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Vol.32/No.4 (128) (2017)

作者:

Vol.32/No.4 (128) (2017)

TitleStudy on the Shear Behavior of Chemical Anchors in the Low Strength Concrete
AuthorJia-MingHsu, Yuan-Liang Zheng, Fu-Pei Hsiao, Wen-I Liao, Pu-Wen Weng, Tai-Kuang Lee, Guo-Luen Huang
Keywordslow strength concrete, adhesive anchors, post-installed rebars, shear, retrofit
AbstractIn order to increase seismic capability of structural system, retrofit techniques are usually applied. Traditional RC retrofit methods include adding RC shear wall, wing wall and RC jacketing. In addition to connect new structural members to old structural members,adhesive anchors (post-installed rebars) are used. From the investigation results by National Center for Research on Earthquake Engineering (NCREE), it was found that concrete strength of old school buildings is very low due to poor construction quality. Therefore, the behavior of post-installed rebars in low strength concrete is very important. In this study, the concrete strength of specimens are 5MPa, 10MPa and 15MPa.According to the minimum edge distance and depth of ACI code, this study proposed a series of anchorage and shear test, a total of 192 specimens. Control parameters are the embedded depth of the rebar, the distance to edge, and concrete strength. The results of those experiments are compared with the calculated values of ACI code. It was found ACI calculated values remain conservative in strength 10MPa and 15MPa, but in the 5MPa calculated values is very close to experiment results.So,the formula of ACI code used in low strength concrete may not be conservative. From the experiments of this study,it was also found a new failure mode as steel bending failure. Finally, the importance of the shear strength of the interface between the post-installed rebar and concrete was addressed with an actual experiment of RC shear wall and the results of the reconnaissance of earthquake disaster in Taiwan.

 

TitleLoading Test Analysis of An Earthquake-Damaged Bridge
AuthorChun-Chung Chen, Yu-Chi Sung, Zheng-Kuan Lee, Chia-Chung Hsu, Fang-Yao Yeh, Yu-Chi Sung, Feng-Kai Chang, Yi-Tsung Chiu, Ping-Hsun Huang, Jia-Ying Chen, Wan-Long Wu
KeywordsGene Algorithm, Response Surface Method, Loading Test
AbstractThis paper conducts an analysis on loading tests of the earthquake-damaged bridge. The study uses the commercial finite element program to build a bridge analytical model, and the analysis result is compared with that of the field load testing to verify the proposed model. Generally, in order to improve the reliability of the finite element model, it is needed to adjust some modeling parameters using field experimental data to realize the representative characteristic of the bridge structure. However, the structural model usually involves numerous elements which lead the poor analysis efficiency of modeling parameters adjustment work. In view of this, this study applies the response method of experimental design function to take place of the finite element model by statistical experimental design theory and integrates the genetic algorithm to optimize modeling parameters which were used in the model and can make the model gives the reliable results which close to static and dynamic characteristics of the actual bridge.
TitleStudy and Establishment for Cloud Platform of Preliminary Seismic Evaluation of Reinforced Concrete Buildings
AuthorYu-Chi Sung, Ming-Chun Lai, Yi-Tsung Chiu, Chun-Jung Chen, Hong-Syuan Lin, Chih-Liang Yen, I-Chau Tsai, Chien-Jung Chen, Chang-Yu Chen
KeywordsCloud Operation System, Quantitative Evaluation, Disaster Prevention
AbstractThe numerous existing buildings maynot behave qualified seismic performance satisfied with the current seismic design code as a result of material deterioration or outdated design, etc. It needs a significant cost and time to do the detailed seismic evaluation of existing buildings for determination on necessary seismic retrofit. Therefore, development of a preliminary seismic evaluation system giving a rapid and reliable result is very important currently in Taiwan. This paper focused on developing the preliminary seismic evaluation of reinforced concrete buildings (PSERCB), based on research of Profs. Tsai and Sung 2014, granted by Architect Research Institute, Taiwan. Both qualitative and quantitative evaluation results are involved in this framework. A cloud platform was established for the engineers to input the inspection of current status of buildings and the evaluation report is able to be downloaded as technical report. All the data on the cloud platform are collected as the basis of big data analysis for strategy of disaster prevention to government in the future.
TitleA Simplified Seismic Analysis Procedure for Vertically Irregular Buildings
AuthorChih-Chia Tsaur, Jui-Liang Lin, Keh-Chyuan Tsai
Keywordsvertically irregular building, setbacks, nonlinear response history analysis, modal pushover analysis, modal response history analysis
AbstractMost seismic building design codes describe the features of vertically irregular buildings. In addition, these building design codes prescribe that dynamic analysis should be adopted in the seismic analysis and design of these irregular structures. Besides the finite element method (FEM), which performs inelastic dynamic analysis to complete finite element models, the modal pushover analysis (MPA) method is one of common simplified seismic analysis procedures. The force-deformation relationship of each vibration mode obtained from the MPA method is employed to construct the corresponding single-degree-of-freedom (SDOF) modal system. The modal response histories are obtained from performing nonlinear response history analysis to each SDOF modal system. The total seismic responses of the building are estimated by adding up the seismic response histories resulting from all vibration modes. This study designates the aforementioned simplified method as the single-degree-of-freedom modal analysis method (SDM). Some research literatures showed that using SDM leads to overestimated seismic responses of the lower parts of the vertically irregular buildings, which have stronger or stronger-and-stiffer bottom story or lower half. Instead of the SDM, the complicated and time-consuming FEM was thus suggested for the seismic analysis of this type of buildings. Nevertheless, this type of vertically irregular buildings is common. It would benefit engineering practice if there are simplified seismic analysis methods available to this type of irregular buildings. In light of the incompetence of using the SDOF modal systems to simultaneously reflect the seismic responses of the super- and sub-structures of the buildings, this study proposes the two-degree-of-freedom modal analysis method (2DM). 2DM is basically the same as SDM, except that 2DM represents each vibration mode as a two-degree-of-freedom modal system. One 9-story and one 20-story regular moment resisting frames are selected as the prototype building in this study. Each of the two prototype buildings are further varied into four vertically irregular buildings as the target buildings. The four variations include buildings with stronger, stronger-and-stiffer first story; stronger, stronger-and-stiffer lower half. FEM, SDM, and 2DM are applied to the eight target buildings subjected to the selected 60 ground motions. This study shows that the analysis results obtained from 2DM are the same as those obtained from SDM as long as the structures remain elastic. While the structures become inelastic, 2DM generally results in more accurate estimations of inter-story drifts, compared with those obtained from SDM. The overestimated peak inter-story drifts of the substructures by using SDM are effectively reduced by using 2DM.
TitleInterference Effects on High-rise Building Based on Aerodynamic and Aeroelastic Tests
AuthorYuan-Lung Lo, Chi-Rou Chen
KeywordsHigh-rise building, Aero-elastic test, Interference effect, Interference factor
AbstractWind effects on high-rise buildings are one of the most important topics in safety designs of structures, especially the target building is neighbored by another or even multiple high-rise buildings. This study intends to compare the differences between the results from the aerodynamic test and the results from the aeroelastic test. Physical scaling tests are planned in three parts: firstly the aerodynamic test is conducted in order to understand mean and fluctuating force coefficients of a square prism model with interference effects; secondly the aeroelastic test is conducted in order to examine the displacement variation under various velocities and terrain flows; thirdly the results from both tests are compared to find the differences by means of displacement estimation methodologies. It is found that, adopting the aerodynamic test for wind-induced response is not reliable compared to the aeroelastic test since the wind-induced response with/without interference effects are much more complicated and need more investigations in systematic aeroelastic test works.

第三十二卷第三期 (期別127) (106年)

作者:

第三十二卷第三期 (期別127) (106年)

標題台灣高強度混凝土彈性模數預估公式研究
作者廖文正、胡瑋秀
關鍵字高強度混凝土、彈性模數、抗壓強度、矽灰、New RC
摘要彈性模數為混凝土在工程設計中的重要材料性質，影響混凝土變形，也是計算撓度和剛度的重要參數。台灣現積極研發New RC 建築技術，採高強度混凝土（f’c > 700 kgf/cm2）搭配高強度鋼筋，朝向超高層鋼筋混凝土建築發展；惟台灣目前對於高強度混凝土彈性模數預估式一般仍採用美國混凝土學會ACI318 或ACI 363 相關規定，然而相關研究已發現由於高漿體量、低粒料強度與矽灰添加等特性，台灣高強度混凝土的彈性模數預估值明顯高估。為了能獲得較準確的彈性模數，須提出一個符合台灣高強度混凝土材料特性之評估計算公式。本研究收集國內本土471 筆的試驗資料，對各參數進行迴歸分析，將矽灰添加等重要參數納入考量；根據研究成果，本研究以ACI 363 彈性模數預估公式為基礎，乘上矽灰折減係數 ksf，除了易於業界計算外，並可反映台灣混凝土彈性模數偏低的現象，並做為未來New RC 構件設計及工程規範修訂的參考。
TitleStudy of Prediction Equation for Modulus of Elasticity of High Strength Concrete in Taiwan
AuthorWen-Cheng Liao, Wei-Xiu Hu
KeywordsHigh Strength Concrete, Modulus of Elasticity, Compressive Strength, Silica Fume, New RC
AbstractThe modulus of elasticity of concrete is an important factor in design of RC structures. Modulus of elasticity is also essential for engineers to estimate deflections and stiffness of RC members. Nowadays, Taiwan New RC project is developing to reduce the member sections and increase the available space of high rise buildings by using high strength concrete (f’c > 700 kgf/cm2) and high strength rebars. However, the prediction and calculation of modulus of elasticity of high strength concrete in Taiwan is still mainly referred to ACI318 or ACI363. It was confirmed that modulus of elasticity of high strength concrete is usually overestimated due to less coarse aggregate amount and high paste volume. In order to gain precise modulus of elasticity, it is necessary to find out an equation which can reflect materials characteristic in Taiwan.This study collects 471 data sets of high strength concrete in Taiwan. By regression analysis with certain key parameters, such as silica fume, a new and practical prediction equation based on the ACI318 is proposed. This equation is easy to calculate and reflects the low modulus of elasticity characteristics in Taiwan. It can offer more accurate estimation of modulus of elasticity for New RC member design.
標題含水平搭接組合繫筋RC柱考慮搭接長度效應之耐震性能
作者李台光、陳正誠、何明錦
關鍵字水平搭接組合繫筋、搭接長度、RC 柱、耐震性能
摘要組合繫筋為由兩支一端為180 度彎鉤另一端為直線的J 形鋼筋搭接組合而成。本研究完成3 支大尺寸鋼筋混凝土柱試體之反復側向載重試驗，探討水平搭接組合繫筋在圍束柱核心混凝土之效應。研究結果顯示：(1)本研究使用之組合繫筋水平搭接長度雖不符合甲級搭接長度之要求，但是由試體之遲滯行為可看出，其圍束效果不亞於兩端為180 度彎鉤之一體繫筋，以及使用90 度-135 度彎鉤之傳統繫筋；(2)組合繫筋之應變量測的結果顯示，組合繫筋發展之強度遠高於單根鋼筋之降伏強度，應變量測結果亦顯示本研究所使用之組合繫筋可以發揮良好的圍束功能；(3)雖然本研究使用之組合繫筋的搭接長度低於甲級搭接長度，而仍然可以發揮預期的功能，但是試驗數據很有限，因此建議組合繫筋還是使用甲級搭接長度；(4)組合繫筋可以大幅改善繫筋之施工性及施工品質，但也會增加鋼筋使用量。本研究探討的個案顯示，使用組合繫筋會使每個塑性鉸區增加11.5 公斤之橫向鋼筋量，柱淨高範圍較傳統繫筋之橫向鋼筋量增加17%。
TitleThe seismic performance of reinforced concrete columns using horizontally lap-spliced crosstie
AuthorTai-Kuang Lee, Cheng-Cheng Chen, Ming-Chin Ho
Keywordshorizontally lap-spliced crosstie, lap splice length, RC columns, seismic performance
AbstractA lap-spliced crosstie consists of two J-shaped steel bars (rebars) that have a straight end and an end featuring a 180° hook. In this study, a lateral cyclic load test was conducted on three specimens of large-sized reinforced concrete (RC) columns to investigate the seismic resistance capability of RC columns comprising horizontally lap-spliced crossties with less than Class A splice length. The research results are presented as follows: (a) The confinement effect of horizontally lap-spliced crosstie with less than Class A splice length, was comparable to that of the specimens using crossties featuring a 180° hook on the two ends and conventional crossties. (b) According to the reading data of strain, the horizontally lap-spliced crosstie can develop the required strength and provide satisfactory confinement effect. (c) In order to be safe and conservative, Class A splice (1.0 times the development length) for lap-spliced crossties is recommended. (d) Using lap-spliced crossties in construction is easy and produces a low possibility of construction errors. Therefore, the construction quality of RC column reinforcement and the seismic resistance capability of RC structures can be substantially increased. The case discussed in this study shows that the use of lap-spliced crosstie would increase the amount of transverse steel in each plastic hinge by 11.5 kg and in the clearance height of columns by 17%.
標題自體調諧質量阻尼系統動力反應最佳化於實務案例之可行性研究
作者陳培榮、劉郁芳、李柏翰、林子剛、張國鎮
關鍵字調諧質量阻尼器、中間樓層隔震、自體調諧質量阻尼器、目標函數、結構控制、動力反應最佳化
摘要近年來隨著隔震設計之建築物蓬勃發展，其中因施工性較優之中間層隔震(Mid-Story Isolation)設計逐漸被廣泛應用，然而中間層隔震設計之高模態參與比例較高，常造成隔震層下部結構反應放大，欲減少隔震層下部反應放大的問題，採用調諧質量阻尼(Tuned Mass Damper，TMD)系統為能量吸收器，於外力作用下與主結構產生反相位運動進而消散外力擾動能量。自體調諧質量阻尼系統(Building Mass Damper System，BMD)將上部結構視為調諧質量，並利用控制層中的橡膠支承墊與黏性阻尼器分別提供BMD 系統所需之勁度及阻尼，結合中間層隔震與調諧質量阻尼器設計之優點，同時控制下部與上部結構反應。數值模型上，以一簡化三自由度模型分別模擬上部結構、控制層及下部結構，進而以三自由度之動力反應總和最小化作為控制目標，推導BMD 最佳化系統(Optimum Building Mass Damper，OBMD)。基於過去研究已分別透過數值模擬及振動台實驗，驗證OBMD 設計於八層樓縮尺構架之可行性，故本研究將針對OBMD 於實際結構之可行性進行探討，因此將採用57 層樓鋼構架作為空構架設計依據，在分析程序上，先根據2%鋼構架初始阻尼比分別設計TMD、BMD 及OBMD 構架，輸入六組不同特性之地震歷時，比較三種系統之歷時反應，同時透過簡化三自由度之加速度轉換函數配合震波FFT 頻涵圖，交互驗證其動態反應。根據第一階段之分析結論，再分別設計下部結構阻尼比為4%之OBMD 構架及一整體阻尼比為4%之消能減震構架，並重新對於空構架、消能減震構架及OBMD 構架進行分析，最後比較最大層間變位角及樓層最大加速度，以驗證OBMD 於實際案例應用之可行性。
TitleFeasibility Study on Building Mass Damper Using Optimum Dynamic Response Control Algorithm for Practical Application
AuthorPei-Rong Chen, Yu-Fang Liu, Bo-Han LEE, Tzu-Kang Lin, Kuo-Chun Chang
KeywordsMid-story isolation system, Tuned mass damper, Building mass damper, Objective function, Optimum Dynamic Response Control Algorithm
AbstractIn a mid-story isolated building, the isolation system is incorporated into the mid-story rather than the base of the building. The effectiveness of mid-story isolation design in reducing seismic demands on the superstructure above the isolation system has been verified in many researches. However, the response of substructure may be amplified due to the flexibility and the contribution of the higher modes. On the other hand, although tuned mass damper has been recognized as an effective energy absorbing device to reduce the undesirable vibrations of the attached vibrating system subjected to harmonic excitations, the mass ratio of most TMD was not enough for earthquake resistance due to the limitation of the building space. Therefore, the concept of building mass damper (BMD) design has been developed, which incorporates the TMD design concept into the mid-story isolated building to control the seismic response of both substructure and superstructure. In the BMD design, the superstructure serves as a tuned absorber mass while the stiffness and damping can be provided by the isolation system composed of elastomeric bearings and additional dampers, as the advantages of conventional TMD and mid-story isolation systems can be integrated. A simplified three-lumped-mass structure model, in which three lumped masses are respectively assigned at the building mass absorber, the control layer, and the primary structure, is rationally assumed to represent a building structure with a BMD system. The reason for doing this is that the inherent dynamic characteristics (fundamental modal characteristics of vibration) of both the building mass absorber and the primary structure can be considered comprehensively in the simplified structure model. The feasibility of the optimum BMD (OBMD) design method has been verified in previous studies. In this research, the 57 story steel frame is used to be a bare frame. According to 2% inherent damping ratios of the TMD, BMD and OBMD can be designed respectively. Six real earthquake records with distinct seismic characteristics adopted in this research are selected for the ground acceleration inputs along the longitudinal and transversal direction. On the other hand, the acceleration transfer functions of the simplified three-lumped-mass structural model and the FFT of each ground motion are used to describe the seismic behavior of the TMD, BMD and OBMD. Then, the seismic responses of the OBMD system are thoroughly investigated and the practicability and effectiveness of the OBMD system for seismic design are verified.
標題移動載重引致鋼承樓版振動之評估
作者翁健煌、李其航
關鍵字樓版振動、鋼承版、移動載重、通用振動標準、1/3 倍頻程譜、SCI P354
摘要一般實驗研究中心的振動敏感設備多規劃於地下室，一方面可減緩建築物外部環境振動之影響；另一方面，當須增加樓版厚度時，因樓版的水平地震力可直接由地下室外牆承擔，故對整體結構設計之影響較小。然而，地下室用途經常包含停車或裝卸貨物，在空間規劃上雖可設置全高RC 牆以區隔車道，或使振動敏感設備盡量遠離車道，但其效果仍須經由樓版振動分析才可確認。本文應用SAP2000 之移動載重分析功能，評估建築物內部車行載重引致的樓版振動，其中，考慮樓版型式為鋼結構常見之鋼承樓版，故結構模擬部分特別參考英國鋼結構學會出版的樓版振動設計指引SCIP354。本文內容包含移動載重模擬、鋼承樓版模擬以及振動標準計算等，其中，振動標準採用高科技廠房常見的通用振動標準，最後，以一動物實驗中心之樓版振動設計為例，詳述各項操作細節和常見問題的解決方法。
TitleEvaluation of composite floor vibrations induced by moving loads
AuthorJian-Huang Weng, Chi-Hang Li
Keywordsfloor vibration, composite floor deck, moving load, generic vibration criteria, one-third octave spectrum, SCI P354
AbstractIn the laboratories or research centers, the vibration-sensitive equipments are often placed on the basement floors. The reason is the impact of environmental vibrations outside the building can be reduced. Another reason is the influence on the structural design will be smaller if the slab thickness needs to be increased because the lateral seismic force of the slab is directly borne by the basement exterior wall. However, basements are often used as parking or loading/unloading spaces so that the vibration induced by vehicle pass-bys may affect the equipments. Although the full height RC partition wall can be used to reduce the vibration and it is also effective to keep the equipments far away from the lane, the result should be confirmed with floor vibration analysis. In this paper, the moving load analysis in SAP2000 is applied to evaluate the floor vibration induced by vehicle traveling inside the building. The publication of Steel Construction Institute: Design of Floor Vibration – A New Approach (SCI P354) is referred as a guideline for structural simulation of the composite floor deck which is commonly used in steel structures. This paper contains simulation of moving load, modeling of composite floor deck and calculation of the generic vibration criteria which is commonly used for high-tech facilities. Finally, an example, design of floor vibration in an animal research facility, is provided to illustrate the design details.
標題國道橋梁耐震補強之碳纖維包覆設計與施工
作者彭康瑜、吳明興、陳建宏、王吉杉、林生發、鄭俊傑
關鍵字橋梁、耐震補強、碳纖維、包覆補強、施工
摘要自有地震儀觀測90 年間以來，臺灣地區已發生多次重大的地震災害。88年9 月21 日發生芮氏地震規模達7.3 的921 集集大地震，造成臺灣相當重大的生命及財產損失，使人不得不懾於大自然無與倫比的力量。此次地震後橋梁結構物之耐震安全成為國家防災計畫非常重要的課題，而國道高速公路為臺灣地區南北交通的大動脈，對於國家整體經濟發展及民生影響甚鉅。臺灣區國道高速公路局為防範於未然，開始分階段持續推動高速公路橋梁耐震評估補強工作。在耐震補強工法中，橋柱包覆補強可有效提升橋梁於強震時之韌性，國內橋梁耐震補強工程常見之包覆補強方式為鋼筋混凝土包覆及鋼板包覆補強工法。鑑於補強材料科技日新月益，碳纖維材料其具有承受主要負載、限制微裂紋延伸、提高材料強度與剛性、改善材料抗疲勞、抗潛變性能及提高材料使用壽命之特性，因此高公局於「國道橋梁耐震強工程」中考量若因空間受限、美觀要求或施工條件不適用混凝土及鋼板包覆工法時，採用纖維強化高分子複合材料包覆工法（FRP 包覆），藉由碳纖維材料重量輕、強度高、易施工等的特性以提高高速公路橋梁的耐震能力與累積本土之設計、施工及檢測維護經驗，期能提供國內橋梁未來耐震補強更多的工法選擇。
TitleDesign and Construction of Carbon Fiber Reinforced Polymer Composite Jacketing for Seismic Retrofit of National Freeway Bridges
AuthorKang-Yu Peng, Ming-Shing Wu, Chien-Hung Chen, Chi-Shan Wang, Sheng-fa Lin, Jun-Jjie Zheng
Keywordsbridge, seismic retrofit, carbon fiber, jacket, construction
AbstractChi-Chi earthquake measuring 7.3 on the Richter scale struck Taiwan on September 21, 1999, and caused severe property losses and casualties to central Taiwan. After the earthquake, the seismic safety of the bridge structure has become a very important issue in the national disaster prevention plan. The national freeway is the main traffic artery connecting the north and south in Taiwan, which has great influence on the national economic development and the people’s livelihood. Taiwan Area National Freeway Bureau (TANFB) actively took preventive measures for the bridge structures. The bridge columns jacketing can effectively increase the flexural ductility and shear strength of the bridge in large earthquake. The reinforced concrete jacketing and steel jacketing are the most widely used in the domestic bridge columns seismic retrofit project. In view of the ever-changing materials technology, carbon fiber material has the characteristics of bearing the load, limiting the micro-crack extension, improving the material strength and rigidity. The material can also improve the material anti-fatigue, anticreep performance and service life. When the space is limited, the landscape requirements or construction conditions are not applicable reinforced concrete jacketing and Steel Jacketing , the seismic retrofit program of national freeway bridges using carbon fiber reinforced polymer composite jacketing (CFRP jacketing). With carbon fiber materials’ light weight, high strength, easy constructed and other characteristics, increase the seismic capacity of freeway bridges, and accumulate the experience of domestic design, construction, testing and maintenance. Looking forward to provide more choice for future domestic bridge seismic retrofit project.

Vol.32/No.3 (127) (2017)

作者:

Vol.32/No.3 (127) (2017)

TitleStudy of Prediction Equation for Modulus of Elasticity of High Strength Concrete in Taiwan
AuthorWen-Cheng Liao, Wei-Xiu Hu
KeywordsHigh Strength Concrete, Modulus of Elasticity, Compressive Strength, Silica Fume, New RC
AbstractThe modulus of elasticity of concrete is an important factor in design of RC structures. Modulus of elasticity is also essential for engineers to estimate deflections and stiffness of RC members. Nowadays, Taiwan New RC project is developing to reduce the member sections and increase the available space of high rise buildings by using high strength concrete (f’c > 700 kgf/cm2) and high strength rebars. However, the prediction and calculation of modulus of elasticity of high strength concrete in Taiwan is still mainly referred to ACI318 or ACI363. It was confirmed that modulus of elasticity of high strength concrete is usually overestimated due to less coarse aggregate amount and high paste volume. In order to gain precise modulus of elasticity, it is necessary to find out an equation which can reflect materials characteristic in Taiwan.This study collects 471 data sets of high strength concrete in Taiwan. By regression analysis with certain key parameters, such as silica fume, a new and practical prediction equation based on the ACI318 is proposed. This equation is easy to calculate and reflects the low modulus of elasticity characteristics in Taiwan. It can offer more accurate estimation of modulus of elasticity for New RC member design.
TitleThe seismic performance of reinforced concrete columns using horizontally lap-spliced crosstie
AuthorTai-Kuang Lee, Cheng-Cheng Chen, Ming-Chin Ho
Keywordshorizontally lap-spliced crosstie, lap splice length, RC columns, seismic performance
AbstractA lap-spliced crosstie consists of two J-shaped steel bars (rebars) that have a straight end and an end featuring a 180° hook. In this study, a lateral cyclic load test was conducted on three specimens of large-sized reinforced concrete (RC) columns to investigate the seismic resistance capability of RC columns comprising horizontally lap-spliced crossties with less than Class A splice length. The research results are presented as follows: (a) The confinement effect of horizontally lap-spliced crosstie with less than Class A splice length, was comparable to that of the specimens using crossties featuring a 180° hook on the two ends and conventional crossties. (b) According to the reading data of strain, the horizontally lap-spliced crosstie can develop the required strength and provide satisfactory confinement effect. (c) In order to be safe and conservative, Class A splice (1.0 times the development length) for lap-spliced crossties is recommended. (d) Using lap-spliced crossties in construction is easy and produces a low possibility of construction errors. Therefore, the construction quality of RC column reinforcement and the seismic resistance capability of RC structures can be substantially increased. The case discussed in this study shows that the use of lap-spliced crosstie would increase the amount of transverse steel in each plastic hinge by 11.5 kg and in the clearance height of columns by 17%.
TitleFeasibility Study on Building Mass Damper Using Optimum Dynamic Response Control Algorithm for Practical Application
AuthorPei-Rong Chen, Yu-Fang Liu, Bo-Han LEE, Tzu-Kang Lin, Kuo-Chun Chang
KeywordsMid-story isolation system, Tuned mass damper, Building mass damper, Objective function, Optimum Dynamic Response Control Algorithm
AbstractIn a mid-story isolated building, the isolation system is incorporated into the mid-story rather than the base of the building. The effectiveness of mid-story isolation design in reducing seismic demands on the superstructure above the isolation system has been verified in many researches. However, the response of substructure may be amplified due to the flexibility and the contribution of the higher modes. On the other hand, although tuned mass damper has been recognized as an effective energy absorbing device to reduce the undesirable vibrations of the attached vibrating system subjected to harmonic excitations, the mass ratio of most TMD was not enough for earthquake resistance due to the limitation of the building space. Therefore, the concept of building mass damper (BMD) design has been developed, which incorporates the TMD design concept into the mid-story isolated building to control the seismic response of both substructure and superstructure. In the BMD design, the superstructure serves as a tuned absorber mass while the stiffness and damping can be provided by the isolation system composed of elastomeric bearings and additional dampers, as the advantages of conventional TMD and mid-story isolation systems can be integrated. A simplified three-lumped-mass structure model, in which three lumped masses are respectively assigned at the building mass absorber, the control layer, and the primary structure, is rationally assumed to represent a building structure with a BMD system. The reason for doing this is that the inherent dynamic characteristics (fundamental modal characteristics of vibration) of both the building mass absorber and the primary structure can be considered comprehensively in the simplified structure model. The feasibility of the optimum BMD (OBMD) design method has been verified in previous studies. In this research, the 57 story steel frame is used to be a bare frame. According to 2% inherent damping ratios of the TMD, BMD and OBMD can be designed respectively. Six real earthquake records with distinct seismic characteristics adopted in this research are selected for the ground acceleration inputs along the longitudinal and transversal direction. On the other hand, the acceleration transfer functions of the simplified three-lumped-mass structural model and the FFT of each ground motion are used to describe the seismic behavior of the TMD, BMD and OBMD. Then, the seismic responses of the OBMD system are thoroughly investigated and the practicability and effectiveness of the OBMD system for seismic design are verified.
TitleEvaluation of composite floor vibrations induced by moving loads
AuthorJian-Huang Weng, Chi-Hang Li
Keywordsfloor vibration, composite floor deck, moving load, generic vibration criteria, one-third octave spectrum, SCI P354
AbstractIn the laboratories or research centers, the vibration-sensitive equipments are often placed on the basement floors. The reason is the impact of environmental vibrations outside the building can be reduced. Another reason is the influence on the structural design will be smaller if the slab thickness needs to be increased because the lateral seismic force of the slab is directly borne by the basement exterior wall. However, basements are often used as parking or loading/unloading spaces so that the vibration induced by vehicle pass-bys may affect the equipments. Although the full height RC partition wall can be used to reduce the vibration and it is also effective to keep the equipments far away from the lane, the result should be confirmed with floor vibration analysis. In this paper, the moving load analysis in SAP2000 is applied to evaluate the floor vibration induced by vehicle traveling inside the building. The publication of Steel Construction Institute: Design of Floor Vibration – A New Approach (SCI P354) is referred as a guideline for structural simulation of the composite floor deck which is commonly used in steel structures. This paper contains simulation of moving load, modeling of composite floor deck and calculation of the generic vibration criteria which is commonly used for high-tech facilities. Finally, an example, design of floor vibration in an animal research facility, is provided to illustrate the design details.
TitleDesign and Construction of Carbon Fiber Reinforced Polymer Composite Jacketing for Seismic Retrofit of National Freeway Bridges
AuthorKang-Yu Peng, Ming-Shing Wu, Chien-Hung Chen, Chi-Shan Wang, Sheng-fa Lin, Jun-Jjie Zheng
Keywordsbridge, seismic retrofit, carbon fiber, jacket, construction
AbstractChi-Chi earthquake measuring 7.3 on the Richter scale struck Taiwan on September 21, 1999, and caused severe property losses and casualties to central Taiwan. After the earthquake, the seismic safety of the bridge structure has become a very important issue in the national disaster prevention plan. The national freeway is the main traffic artery connecting the north and south in Taiwan, which has great influence on the national economic development and the people’s livelihood. Taiwan Area National Freeway Bureau (TANFB) actively took preventive measures for the bridge structures. The bridge columns jacketing can effectively increase the flexural ductility and shear strength of the bridge in large earthquake. The reinforced concrete jacketing and steel jacketing are the most widely used in the domestic bridge columns seismic retrofit project. In view of the ever-changing materials technology, carbon fiber material has the characteristics of bearing the load, limiting the micro-crack extension, improving the material strength and rigidity. The material can also improve the material anti-fatigue, anticreep performance and service life. When the space is limited, the landscape requirements or construction conditions are not applicable reinforced concrete jacketing and Steel Jacketing , the seismic retrofit program of national freeway bridges using carbon fiber reinforced polymer composite jacketing (CFRP jacketing). With carbon fiber materials’ light weight, high strength, easy constructed and other characteristics, increase the seismic capacity of freeway bridges, and accumulate the experience of domestic design, construction, testing and maintenance. Looking forward to provide more choice for future domestic bridge seismic retrofit project.

第三十二卷第二期 (期別126) (106年)

作者:

第三十二卷第二期 (期別126) (106年)

標題含鋼板阻尼器構架耐震設計與分析
作者許仲翔、李昭賢、金步遠、蔡克銓
關鍵字鋼板阻尼器、容量設計、耐震設計、有限元素模型分析、非線性結構分析
摘要鋼板阻尼器(Steel Panel Damper, SPD)為耐震間柱的一種，在抗彎構架(Moment Resisting Frame, MRF)中設置SPD 可增加結構的側向勁度、強度與韌性。本文利用兩組SPD 試體說明SPD 的構造原理與力學特性，介紹三段式SPD 容量設計與延遲塑性挫屈加勁設計方法。另介紹含鋼板阻尼器構架(SPD-MRF)的耐震設計，與邊界梁容量設計，並設計一棟六層SPD-MRF 範例，來闡明SPD-MRF 塑鉸產生機制與非線性動力歷時分析結果。分析證實ABAQUS 有限元素、PISA3D 結構模型均能準確模擬試體之反覆受力變形反應。統計非線性動力歷時分析結果可得MCE 級地震作用下，SPD 核心段最大剪變形角平均值加標準差為0.055 弧度，而兩組SPD 試體反覆載重試驗結果核心段最大剪變形角皆可達0.11 弧度，且累積塑性變形可達127 以上，約可承受4 次MCE 級地震才可能產生破壞。顯示本文所提之三段式SPD 具備足夠的耐震容量。最後本文提出以等效單構件模擬三段式SPD 的建模方法，並探討連接段相對長度與勁度對整體SPD 彈性勁度、降伏側位移角與降伏後勁度之影響，說明設計適當之上下連接段不僅能確保彈性反應，還能在保持SPD 的強度下，調節整體SPD 之降伏側位移角、彈性與降伏後勁度。
TitleSeismic Design, Tests and Analysis of Steel Panel Dampers for Steel Moment Frames
AuthorChung-Hsiang Hsu, Chao-Hsien Li, Pu-Yuan Chin, Keh-Chyuan Tsai
Keywordssteel panel damper, capacity design, seismic design, finite element model analysis, non-linear structural analysis
AbstractA ductile vierendeel frame can be constructed by incorporating the steel panel dampers (SPDs) into the moment resisting frame (SPD-MRF). Thus, the lateral stiffness, strength and energy dissipation capacity of the building can be enhanced.This paper presents the mechanical properties, capacity design procedures and the buckling-delaying stiffeners for the proposed 3-segment SPDs using two specimens subjected to cyclic increasing deformations. This paper also discusses the seismic design procedures of the SPD itself and the boundary beams connected to the SPDs in typical SPD-MRFs. Tests confirm that the proposed SPDs possess excellent ductility and energy dissipation capacities. The cyclic force vs. deformation relationships of the two SPD specimens can be accurately predicted using either the ABAQUS or PISA3D model analyses. This paper also investigates the seismic performance of a 6-story example SPD-MRF by using nonlinear response history analysis procedures and 240 ground accelerations. Results indicate that under the 80 MCE ground accelerations, the mean plus one standard deviation shear deformation of the SPD inelastic core segment is 0.055 radian, substantially less than the 0.11 radian capacity observed from both two SPD specimens. In addition, the cumulative plastic deformation of the proposed SPD is 127 times the yield deformation, capable of sustaining the MCE at least 4 times before failure. This paper concludes the method of using one equivalent element for effective modeling of the 3-segment SPD. The effects of the core segment relative length and stiffness on the overall SPD elastic, post-elastic stiffness, elastic deformation limit and inelastic deformational demand are discussed.
標題全尺寸二層樓雙核心自復位斜撐構架與夾型挫屈束制斜撐構架之耐震試驗與非線性動力歷時分析
作者周中哲、蕭佳宏、陳澤邦、鍾秉庭、范廷海
關鍵字雙核心自復位斜撐、夾型挫屈束制斜撐、二層樓鋼構架試驗
摘要雙核心自復位斜撐是利用斜撐中的兩組拉力構件束制斜撐中的三組鋼受壓構件，並利用第一核心構件與外層構件之相對位移進行摩擦消能，使斜撐受軸拉與軸壓下提供自復位及消能能力，即在大變形下具有回到零殘餘變形的能力；夾型挫屈束制斜撐則是利用兩組獨立分離的圍束構件以栓接方式束制斜撐中的核心構件，使得斜撐受壓不會挫屈而產生飽滿的遲滯消能。本研究主要目的為比較雙核心自復位斜撐與夾型挫屈束制斜撐安裝在相同梁柱構架下的影響，因此設計三組三層樓鋼造斜撐構架，分別為雙核心自復位斜撐構架(Dual-Core Self-Centering Braced Frame, DC-SCBF)、特殊混合斜撐構架(Special Mixed Braced Frame, SMBF)及夾型挫屈束制斜撐構架(Sandwiched Buckling-Restrained Braced Frame, SBRBF)，其中特殊混合斜撐構架之斜撐由雙核心自復位斜撐和夾型挫屈束制斜撐分別配置於不同樓層，目的是結合兩種不同力學行為的斜撐於單一構架中進行抗震。本研究以非線性側推及動力歷時分析三組斜撐構架在20 組強地動地震紀錄下的反應，並於實驗室進行三組全尺寸二層樓鋼造斜撐構架試驗，目的為檢驗三組斜撐構架的側向勁度、能量消散、殘餘變位、累積韌性、等效阻尼比及耐震性能等抗震行為。
TitleSeismic Tests and Nonlinear Time History Analyses of Full-Scale Two-Story Steel Frames with DC-SCBs and SBRBs
AuthorChung-Che Chou, Chia-Hung Hsiao, Ze-Bang Chen, Ping-Ting Chung, Dinh-Hai Pham
KeywordsDual-core self-centering brace (DC-SCB), Sandwiched buckling-restrained brace (SBRB), Tests of two-story steel braced frames
AbstractTraditional seismic resisting systems in a large earthquake can experience significant damage and residual drifts due to energy dissipation of some structural members, which leads to difficult or expensive to repair after earthquakes. A steel dual-core self-centering brace (DC-SCB), which utilizes three steel bracing members, two friction devices, and two sets of tensioning elements that are in a parallel arrangement for doubling its axial deformation, has been proposed and validated to provide both the energy dissipation and self-centering properties to seismic resisting systems. A prototype three-story steel dual-core self-centering braced frame (DC-SCBF) was designed, and its full-scale one-bay DC-SCBF was tested to validate the system response. The DC-SCB was then replaced by the sandwiched buckling-restrained brace (SBRB) in a full-scale two-story frame, so the seismic performance of the DC-SCBF and the special mixed braced frame (SMBF) that has both the DC-SCB and SBRB in a frame could be evaluated. The full-scale two-story DC-SCBF, SMBF and BRBF subassembly specimen performed well up to an interstory drift of 2% after multiple tests. Nonlinear time history analyses were also performed on the prototype braced frames to obtain seismic demands.
標題單擺式滑動隔震系統於水平垂直雙向地震力作用下之曲面效應理論與實驗探討
作者蔡諄昶、盧煉元、王亮偉、鍾立來
關鍵字滑動隔震、摩擦單擺支承、曲面效應、耦合效應、垂直震波、極限地震力、雙向地震力
摘要摩擦單擺支承(FPS)為目前使用最廣之滑動式隔震支承，該類支承之滑動面為具有固定曲率半徑之圓球面，以便提供隔震系統所需之回復力，並以滑動摩擦提供系統所需之消能能力。目前常用之FPS 隔震分析模型多以一固定勁度之彈簧及定摩擦之元件加以並聯而成。此種模型係假設支承位移遠小於曲率半徑故支承回復勁度近似常數，同時忽略滑動曲面傾角對回復力及摩擦子正向力之影響。此種簡化式模型在支承位移較小時或可提供足夠的精度，但在極大地震力或具速度脈衝特性之近斷層震波作用下，支承位移與速度有可能急速增加，此時滑動曲面效應對隔震動力行為即可能產生可觀之影響。為能補捉FPS 隔震系統於極大地震力作用下之真實隔震行為，本文以拉格朗運動方程式推導該系統於水平與垂直雙向震波同時作用下之完整運動方程式。經由本文所推導之方程式可知，FPS 隔震系統之水平與垂直向運動方程式實應包含二個與曲面斜率及曲率相關之非線性高階項，同時此二項又分別與支承水平滑動加速度及速度相關，因而造成隔震系統垂直與水平運動間之耦合效應，並產生額外之垂直向加速度及支承軸壓力等效應，本文經由振動台實驗並進一步證實此耦合效應之存在。本文進一步利用所推導之完整分析模型，並採用168 筆不同強度之水平與垂直雙向震波以進行剛性結構之隔震模擬。初步研究結果顯示，支承曲面效應對於隔震結構水平向反應(水平上傳加速度與支承位移)之影響較為有限，但對於隔震結構之垂直向反應(垂直上傳加速度與支承正向力)則有較大之影響。若忽略曲面效應可能低估垂直向反應達20%以上，部份震波甚至可達40%以上。
TitleCurvature effect on seismic responses of pendulum sliding isolators subjected to vertical and horizontal bi-directional ground excitations
AuthorChun-Chung Tsai, Lyan-Ywan Lu, Liang-Wei Wang, Lap-Loi Chung
Keywordsbase isolation, sliding isolation, pendulum isolator, curvature effect, bi-direction excitation, centrifugal force
AbstractFriction pendulum system (FPS) isolator is one of most widely used sliding isolators, presently. This type of isolators usually has a spherical sliding surface with constant radius, in order to produce a restoring force for the isolation system. The energy dissipation of the isolator is provided by sliding friction force. The common model adopted for an FPS isolator usually contains a constant-stiffness spring and a friction element placed in parallel. This model assumes that the isolator displacement is much smaller than the radius of the sliding surface, therefore the curvature and slope effects of the spherical surface on the restoring and friction forces can be neglected. This simplified model may not be applicable for FPS isolators under earthquakes that produce large isolator displacements or sliding velocities, since in these earthquakes the curvature and slope of the sliding surface may have significant effects on the dynamic response of the isolation system. In order to capture the actual response of a FPS-isolated structural system under an extreme earthquake, in this paper, complete dynamic equations of motion for the isolation system under vertical-and-horizontal bi-directional ground excitations were derived by using Lagrange’s equation. It is shown that the derived governing equations in both horizontal and vertical directions contain high-order nonlinear terms related to the slope and curvature of the sliding surface. These terms that are functions of horizontal sliding velocity and acceleration cause the coupling effect between horizontal and vertical motions and result in extra vertical acceleration and isolator axial load. The existence of the coupling effect was further verified by the shaking table test conducted in this study. In addition, by using the derived complete dynamic equations, the time responses of a FPS-isolated rigid structure under 168 ground motions with different intensities and characteristics were simulated. The simulation result demonstrates that the high-order terms have less effect on the horizontal response (acceleration and isolator drift) of the isolated system, but are more influential on the vertical responses (acceleration and isolator axial load). Neglecting the high-order terms may underestimate the vertical response by about 20-40% in a sever earthquake.

 

標題SRC結構營造施工安全問題之探討
作者彭瑞麟、何崇銘、李文進、呂良正
關鍵字臨界載重、直接分析法、二階分析、SRC結構
摘要SRC 結構(Steel Reinforced Concrete)是融合SS 結構(Steel Structure)與RC 結構(Reinforced Concrete)的優點，將鋼筋混凝土與鋼骨結合，以增加結構的延展性、耐震性及耐火性。近年來，一些安全及耐震要求高的建案，多會採用SRC 結構進行設計。但SRC 結構在施工過程中，若無正確施工程序，則易造成未預期的施工荷重而發生倒塌。本文即以國內一件SRC 結構施工中倒塌案例，利用二階分析及複合式柱之簡化模式解析解，來探討SRC施工中結構的安全問題。研究結果顯示：經由二階分析確認，設計者可能未考慮SRC 施工中鋼骨整體自重已超過SRC 施工中結構的臨界載重，此造成SRC 施工中結構系統發生挫屈，在受微小擾動後立即瞬間倒塌。複合式柱之簡化模式分析結果顯示，當SRC 結構施工程序比照SS 結構施工程序，持續往上吊裝鋼樑鋼柱而不顧下層鋼筋混凝土梁柱施工進度，則SRC 上層鋼骨自重可能會超過SRC 施工中結構的臨界載重，進而發生倒塌。為避免SRC 結構於施工過程中發生倒塌，建議政府主管機關，在施工方面，應制訂SRC 安全組裝施工程序，使鋼骨吊裝作業與鋼筋混凝土作業能完美結合；在設計方面，參考先進國家鋼結構設計規範，將直接分析法或二階分析納入我國鋼結構設計規範，以供設計者遵循。
TitleInvestigation on Safety Problems of SRC Structures used in Construction
AuthorJui-Lin Peng, Chung-Ming Ho, Wen-Jinn Lee, Liang-Jenq Leu
Keywordscritical load, direct analysis method, second-order analysis, steel reinforced concrete structure
AbstractThe steel reinforced concrete structures (SRC) integrate into the merits of steel structures (SS) and reinforced concrete structures (RC). The steel reinforced concrete structures, combined by reinforced concrete and steel structures, have a good ductility, earthquake resistantce and fire resistance. In recent years, some construction projects with high safety and seismic requirements have considered the design of steel reinforced concrete. However, in the construction of SRC structures, an unexpected construction load may cause the collapse of SRC structures if the correct construction procedures is not considered. This study investigates the construction safety of SRC structure based on the collapse of a SRC structure using a second-order analysis and a simplified model of composite columns. The study result of the second-order analysis shows that designers might fail to consider the overall steel self-weight of the SRC construction structure to exceed the critical load of this structure. This caused that the SRC construction structure buckled and then immediately collapsed after a slight disturbance. The analysis result of the simplified model of the composite column shows that the self-weight of SRC may exceed the critical load of the SRC construction structure and then the structure fails finally. The analysis result implies that the SRC construction structure collapses if the construction procedure of SRC only follows that of SS regardless of the setup progress of reinforced concrete beams and columns at the bottom. In order to avoid the collapse of SRC construction structure, this study proposes that, in terms of construction, the government authorities should develop a safety assembly procedure of SRC structures so that the hoisting of steel beams and columns can combine reinforced concrete operations perfectly. In terms of design, the government authorities should add the direct analysis method or the second-order analysis into the domestic design specifications of steel structures based on those used in advanced countries.
標題樁基礎沖刷橋梁模型之振動台實驗與分析研究
作者劉光晏、陳正鴻、陳家漢、張國鎮
關鍵字振動台實驗、樁基礎、沖刷、土壤彈簧
摘要本研究提出土壤結構互制分析之簡化分析流程，探討樁基礎橋梁受地震與沖刷之複合式災害作用下之受震反應。土壤結構互制行為係以等效線性土壤彈簧模擬，主要特點為採用實測之土壤剪力波速與動態剪力模數來推估土壤彈簧之初始值，並假設樁身近域土壤與樁體產生相同剪力變形，根據地震作用下之土層有效剪應變對動態剪力模數進行修正，經少量迭代後獲致合理的等效線性土壤彈簧。此外，本研究建議地震時之土壤分層方式，根據白噪音訊號或者地震訊號作用下之土層加速度進行轉換函數，作為單層土及雙層土模型之依據。基於前述方法，本研究比較樁基礎沖刷橋梁模型之振動台實驗成果。分析結果顯示，無論在基樁有無裸露條件下，均能有效模擬上部結構之相對位移、絕對加速度，樁頂應變等之歷時與峰值，與沿樁長各高程之最大應變，且雙層土模型之預測結果均較單層土模型更佳準確。
TitleNumerical simulation of shaking table tests on dynamic response of a bridge model with scoured piled foundation
AuthorKuang-Yen Liu, Zheng-Hong Chen, Chia-Han Chen, Kuo-Chun Chang
KeywordsShaking table test, Pile foundation, Scouring effect, Soil springs
AbstractThe simplified analysis process of soil-structure interaction is proposed in this research to study the response of the bridge with scoured piled foundation under earthquake. The simplified analysis applies soil spring to simulate soil-structure interaction behavior. Both soil shear wave velocity and dynamic shear modulus are used to estimate initial value of linear soil spring. Given two assumptions: (1) the shear strain of the soil near the pile is consistent to the strain of the pile, and (2) modification of dynamic shear modulus of soil follows the relationship of effective shear strain and maximum shear modulus, proposed by Seed and Idriss, the parameters of soil springs can be determined iteratively. Furthermore, a simplified approach to identify the soil layers subjected to seismic loading was also introduced by the predominant frequencies of soil layers by the transfer function analysis. Based on the proposed method, the SDOF bridge model with equivalent linear soil springs was built to simulate behavior of soil-pile-structure interaction in the shaking table test. The acceleration and relative displacement of superstructure, the strain of pile top, and the maximum strain of pile can be effectively predicted by the proposed method, either in the condition of exposed or no exposed pile foundation. In addition, the analyzed result of the model considering the double layers of soil can obtain better accuracy than that of the model with single layer of soil.

Vol.32/No.2 (126) (2017)

作者:

Vol.32/No.2 (126) (2017)

TitleSeismic Design, Tests and Analysis of Steel Panel Dampers for Steel Moment Frames
AuthorChung-Hsiang Hsu, Chao-Hsien Li, Pu-Yuan Chin, Keh-Chyuan Tsai
Keywordssteel panel damper, capacity design, seismic design, finite element model analysis, non-linear structural analysis
AbstractA ductile vierendeel frame can be constructed by incorporating the steel panel dampers (SPDs) into the moment resisting frame (SPD-MRF). Thus, the lateral stiffness, strength and energy dissipation capacity of the building can be enhanced.This paper presents the mechanical properties, capacity design procedures and the buckling-delaying stiffeners for the proposed 3-segment SPDs using two specimens subjected to cyclic increasing deformations. This paper also discusses the seismic design procedures of the SPD itself and the boundary beams connected to the SPDs in typical SPD-MRFs. Tests confirm that the proposed SPDs possess excellent ductility and energy dissipation capacities. The cyclic force vs. deformation relationships of the two SPD specimens can be accurately predicted using either the ABAQUS or PISA3D model analyses. This paper also investigates the seismic performance of a 6-story example SPD-MRF by using nonlinear response history analysis procedures and 240 ground accelerations. Results indicate that under the 80 MCE ground accelerations, the mean plus one standard deviation shear deformation of the SPD inelastic core segment is 0.055 radian, substantially less than the 0.11 radian capacity observed from both two SPD specimens. In addition, the cumulative plastic deformation of the proposed SPD is 127 times the yield deformation, capable of sustaining the MCE at least 4 times before failure. This paper concludes the method of using one equivalent element for effective modeling of the 3-segment SPD. The effects of the core segment relative length and stiffness on the overall SPD elastic, post-elastic stiffness, elastic deformation limit and inelastic deformational demand are discussed.
TitleSeismic Tests and Nonlinear Time History Analyses of Full-Scale Two-Story Steel Frames with DC-SCBs and SBRBs
AuthorChung-Che Chou, Chia-Hung Hsiao, Ze-Bang Chen, Ping-Ting Chung, Dinh-Hai Pham
KeywordsDual-core self-centering brace (DC-SCB), Sandwiched buckling-restrained brace (SBRB), Tests of two-story steel braced frames
AbstractTraditional seismic resisting systems in a large earthquake can experience significant damage and residual drifts due to energy dissipation of some structural members, which leads to difficult or expensive to repair after earthquakes. A steel dual-core self-centering brace (DC-SCB), which utilizes three steel bracing members, two friction devices, and two sets of tensioning elements that are in a parallel arrangement for doubling its axial deformation, has been proposed and validated to provide both the energy dissipation and self-centering properties to seismic resisting systems. A prototype three-story steel dual-core self-centering braced frame (DC-SCBF) was designed, and its full-scale one-bay DC-SCBF was tested to validate the system response. The DC-SCB was then replaced by the sandwiched buckling-restrained brace (SBRB) in a full-scale two-story frame, so the seismic performance of the DC-SCBF and the special mixed braced frame (SMBF) that has both the DC-SCB and SBRB in a frame could be evaluated. The full-scale two-story DC-SCBF, SMBF and BRBF subassembly specimen performed well up to an interstory drift of 2% after multiple tests. Nonlinear time history analyses were also performed on the prototype braced frames to obtain seismic demands.
TitleCurvature effect on seismic responses of pendulum sliding isolators subjected to vertical and horizontal bi-directional ground excitations
AuthorChun-Chung Tsai, Lyan-Ywan Lu, Liang-Wei Wang, Lap-Loi Chung
Keywordsbase isolation, sliding isolation, pendulum isolator, curvature effect, bi-direction excitation, centrifugal force
AbstractFriction pendulum system (FPS) isolator is one of most widely used sliding isolators, presently. This type of isolators usually has a spherical sliding surface with constant radius, in order to produce a restoring force for the isolation system. The energy dissipation of the isolator is provided by sliding friction force. The common model adopted for an FPS isolator usually contains a constant-stiffness spring and a friction element placed in parallel. This model assumes that the isolator displacement is much smaller than the radius of the sliding surface, therefore the curvature and slope effects of the spherical surface on the restoring and friction forces can be neglected. This simplified model may not be applicable for FPS isolators under earthquakes that produce large isolator displacements or sliding velocities, since in these earthquakes the curvature and slope of the sliding surface may have significant effects on the dynamic response of the isolation system. In order to capture the actual response of a FPS-isolated structural system under an extreme earthquake, in this paper, complete dynamic equations of motion for the isolation system under vertical-and-horizontal bi-directional ground excitations were derived by using Lagrange’s equation. It is shown that the derived governing equations in both horizontal and vertical directions contain high-order nonlinear terms related to the slope and curvature of the sliding surface. These terms that are functions of horizontal sliding velocity and acceleration cause the coupling effect between horizontal and vertical motions and result in extra vertical acceleration and isolator axial load. The existence of the coupling effect was further verified by the shaking table test conducted in this study. In addition, by using the derived complete dynamic equations, the time responses of a FPS-isolated rigid structure under 168 ground motions with different intensities and characteristics were simulated. The simulation result demonstrates that the high-order terms have less effect on the horizontal response (acceleration and isolator drift) of the isolated system, but are more influential on the vertical responses (acceleration and isolator axial load). Neglecting the high-order terms may underestimate the vertical response by about 20-40% in a sever earthquake.
TitleInvestigation on Safety Problems of SRC Structures used in Construction
AuthorJui-Lin Peng, Chung-Ming Ho, Wen-Jinn Lee, Liang-Jenq Leu
Keywordscritical load, direct analysis method, second-order analysis, steel reinforced concrete structure
AbstractThe steel reinforced concrete structures (SRC) integrate into the merits of steel structures (SS) and reinforced concrete structures (RC). The steel reinforced concrete structures, combined by reinforced concrete and steel structures, have a good ductility, earthquake resistantce and fire resistance. In recent years, some construction projects with high safety and seismic requirements have considered the design of steel reinforced concrete. However, in the construction of SRC structures, an unexpected construction load may cause the collapse of SRC structures if the correct construction procedures is not considered. This study investigates the construction safety of SRC structure based on the collapse of a SRC structure using a second-order analysis and a simplified model of composite columns. The study result of the second-order analysis shows that designers might fail to consider the overall steel self-weight of the SRC construction structure to exceed the critical load of this structure. This caused that the SRC construction structure buckled and then immediately collapsed after a slight disturbance. The analysis result of the simplified model of the composite column shows that the self-weight of SRC may exceed the critical load of the SRC construction structure and then the structure fails finally. The analysis result implies that the SRC construction structure collapses if the construction procedure of SRC only follows that of SS regardless of the setup progress of reinforced concrete beams and columns at the bottom. In order to avoid the collapse of SRC construction structure, this study proposes that, in terms of construction, the government authorities should develop a safety assembly procedure of SRC structures so that the hoisting of steel beams and columns can combine reinforced concrete operations perfectly. In terms of design, the government authorities should add the direct analysis method or the second-order analysis into the domestic design specifications of steel structures based on those used in advanced countries.
TitleNumerical simulation of shaking table tests on dynamic response of a bridge model with scoured piled foundation
AuthorKuang-Yen Liu, Zheng-Hong Chen, Chia-Han Chen, Kuo-Chun Chang
KeywordsShaking table test, Pile foundation, Scouring effect, Soil springs
AbstractThe simplified analysis process of soil-structure interaction is proposed in this research to study the response of the bridge with scoured piled foundation under earthquake. The simplified analysis applies soil spring to simulate soil-structure interaction behavior. Both soil shear wave velocity and dynamic shear modulus are used to estimate initial value of linear soil spring. Given two assumptions: (1) the shear strain of the soil near the pile is consistent to the strain of the pile, and (2) modification of dynamic shear modulus of soil follows the relationship of effective shear strain and maximum shear modulus, proposed by Seed and Idriss, the parameters of soil springs can be determined iteratively. Furthermore, a simplified approach to identify the soil layers subjected to seismic loading was also introduced by the predominant frequencies of soil layers by the transfer function analysis. Based on the proposed method, the SDOF bridge model with equivalent linear soil springs was built to simulate behavior of soil-pile-structure interaction in the shaking table test. The acceleration and relative displacement of superstructure, the strain of pile top, and the maximum strain of pile can be effectively predicted by the proposed method, either in the condition of exposed or no exposed pile foundation. In addition, the analyzed result of the model considering the double layers of soil can obtain better accuracy than that of the model with single layer of soil.

第三十二卷第一期 (期別125) (106年)

作者:

第三十二卷第一期 (期別125) (106年)

標題方螺箍混凝土梁耐震行為研究
作者王柄雄、歐昱辰、尹衍樑、王瑞禎、吳振維、陳智軒、張國鎮
關鍵字方螺箍、梁、塑鉸、反覆載重
摘要本文進行鋼筋混凝土梁橫向鋼筋採連續方形螺箍之試驗研究，文中規劃三組梁柱接頭外柱接頭試體，其梁箍筋分別為傳統橫箍、單個方螺箍及兩個方螺箍嵌合型式，探討在梁端塑鉸行為控制前提下，梁受反復載重作用之耐震性能。試驗結果顯示，單方螺箍梁試體與傳統橫箍梁之耐震性能相近，而雙方螺箍梁由於塑鉸端部之箍筋缺乏適當錨定，以致在大側向變位之反覆加載下會有較嚴重的破壞。在箍筋製作的比較上，方螺箍可採自動化設備生產且組立快速，可省去傳統箍筋之彎鉤用量約25%，及節省箍筋加工綁紮的費用與時間。
TitleSeismic Behavior of Reinforced Concrete Beams with Rectangular Spiral Reinforcement
AuthorPing-Hsiung Wang, Kuo-Chun Chang, Yu-Chen Ou, Samuel Y. Yin, Jui-Chen Wang, Chih-Hsuan Chen, Chen-Wei Wu
Keywordsrectangular spiral, beam, plastic hinge, cyclic loading
AbstractThis paper presents an experimental study on reinforced concrete beam with continuous rectangular spiral as transverse reinforcement. Three exterior beam-column joint specimens with different beam detailing were devised to exhibit beam hinging and to examine their seismic performance under pseudo-static cyclic loading. Two beams with single and double rectangular spirals were introduced to compare with the one with traditional hoops. Test results show that beam specimen with single rectangular spiral has comparable hysteresis behavior compared to the traditional one, while the one with double rectangular spiral exhibits more degradation due to inadequate detailing at the end of spiral. Without the need of anchored hooks on each hoop, beam with rectangular spiral can save around 25% of transverse reinforcement in comparison with traditional hoops. Moreover, rectangular spiral can be automatically produced and easily erected with less labor effort.
標題高強度混凝土充填箱型鋼柱於高軸力下之耐震試驗
作者周中哲、吳松城
關鍵字高強度材料、混凝土充填箱型鋼柱、高軸力梁柱構件、耐震試驗
摘要高樓建築結構中的低樓層柱常會因載重要求及尺寸的限制而有使用高強度材料的需求， 因此本研究探討高強度混凝土充填高強度箱型鋼柱（Concrete Filled Box Column, CFBC）於高及低軸力(40%及20%軸力強度)下之耐震行為，主要試驗參數包括鋼柱寬厚比、軸力大小及斷面配置，共計有六組試體，試驗方式為對柱施加固定軸力並進行反覆側推試驗。鋼柱方形斷面寬分別為420、400 及280 mm，寬厚比分別為11、18 及30，試體使用高強度SM 570M 鋼材（實際降伏強度520~580MPa）及高強度混凝土（實際 f’c = 80 MPa）。研究結果顯示寬厚比增加會小幅降低柱韌性，但柱軸力大小對柱韌性之影響非常顯著，於高軸力下柱的韌性低，而銲接箱型柱斷面內充填混凝土與否對韌性並無明顯影響。本研究也將實驗所得的強度與各國規範進行比較，發現歐洲EC 規範及日本AIJ 規範對於高強度混凝土充填箱型鋼柱之強度預測較為準確，美國AISC、ACI 及台灣規範均過於保守；各規範對於高強度箱型鋼柱之強度預測均偏於保守，對於寬厚比較小之柱試體，預測誤差較大。
TitleSeismic Tests of High Strength Concrete Filled Box Columns under Large Axial Loads
AuthorChung-Che Chou, Sung-Cheng Wu
KeywordsHigh strength material, Concrete filled box column, High axial load beam-column specimen
AbstractThe cyclic behavior of high strength Concrete Filled Box Column (CFBC) under large axial loads was experimentally investigated. The parameters in the study included the width-to-thickness (b/t) ratio, axial load level and section type. Total six beam-column specimens were tested under a constant axial load and an increasing cyclic loading. The CFBC specimens were 280 to 420 mm in width and 2000 mm in height. Nominal b/t ratios varied from 11 to 30. All specimens were made of high strength steel SM 570M with a nominal yield strength of520~580 MPa.Three specimens were filled with high strength (80 MPa) concrete. Experimental results indicated that ductility decreases significantly with an increase in either axial load level or b/t ratio of the steel. The ductility does not change significantly whether concrete is infilled in the steel box column. Eurocode (EC 2004) and Architectural Institute of Japan (AIJ 2010) have good prediction in the flexural strength of high strength CFBC. AISC-LRFD (2010), ACI 318 (2011) and Taiwan Steel Design Code (2010) are too conservative in predicting the flexural strength of high strength CFBC. All the design codes are conservative in predicting high strength steel column moment capacity, especially for small b/t ratios.
標題耦合結構牆性能化抗震設計法
作者洪崇展、盧威廷、鄭宇翔
關鍵字耦合結構牆、性能化設計、抗震行為、結構設計
摘要耦合結構牆乃由兩座以上之結構牆，由連接梁結合成一體之結構物，常用以增加位處地震頻繁區域內中高層建物之側向強度與勁度。現今耐震設計規範乃基於強度設計法，雖可確保結構物於強震下之安全，卻無法使設計者或使用者得知結構物於不同層級地震下之預期行為。本研究目標為發展耦合結構牆之性能化設計法，允許設計者選定不同地震災害等級下之結構性能目標，依此目標以及選定之耦合率進行結構設計，並使耦合結構牆得以於地震時展現理想之降伏消能機制，充分發揮非彈性變形消能之能力。文中以四座耦合結構牆為設計範例，闡述設計流程，並建立其有限元素分析模型，以非線性動態歷時分析，模擬耦合牆系統之地震行為，分析結果顯示，使用本文建議之性能化設計法，不僅可使耦合牆系統展現良好之降伏消能機制，並可於不同地震災害層級下，分別達成預設之性能目標。
TitlePerformance-based design for earthquake-resistant coupled structural walls
AuthorChung-Chan Hung , Yu-Hsiang Cheng ,Wei-Ting Lu
Keywordscoupled structural walls, performance-based design, nonlinear time-history analysis
AbstractCoupled structural walls are often used in the buildings located in regions with high seismic risk. A coupled wall structure consists of two or more structural walls linked by coupling beams. It is able to provide efficient lateral strength and stiffness, which effectively reduces the drift response of buildings under earthquakes. Current seismic design codes are based on strength methods. Although they are able to prevent structures that are designed accordingly from collapse, the designers and users have limited knowledge about the seismic behavior of the designed structures under different levels of earthquakes. The objective of the present study is to develop a performance-based design method for coupled walls. The developed method allows engineers to pre-select the desirable coupling ratio and performance objectives for coupled walls, and then design the structures accordingly. In addition, it also facilitates the ideal yielding mechanism of coupled walls under earthquakes. Four example coupled wall structures are designed in this study using the proposed method. Their computational models are also built and analyzed using nonlinear time history procedures. The results show that the designed coupled walls are able to exhibit satisfactory structural yielding mechanisms and show the seismic behavior satisfying the pre-selected performance objectives for different seismic hazard levels.
標題考慮地盤種類之隔震黏滯阻尼比最佳化設計公式
作者楊卓諺、范揚志、鍾立來、陸寶軍
關鍵字設計公式、隔震、黏滯阻尼、最佳化、地盤
摘要本文旨在探討隔震系統輔以黏滯阻尼消能之最佳阻尼比，系統之回復力與阻尼力皆為線性。因前人所用之地表加速度為白雜訊，並未顯現出台灣地盤之特性，故本文以台灣177 個地震紀錄作為地表加速度。並將結構物分成剛體結構與非剛體結構，非剛體結構再以無阻尼以及含阻尼作為劃分。再來根據結構的分類表建立運動方程式，利用狀態空間法以數值模擬求得不同結構參數與地盤種類的動力反應。藉由變化阻尼比，使上部結構絕對加速度反應最小之阻尼比即為最佳阻尼比，進一步利用這些參數與對應之最佳阻尼比迴歸出設計公式。最後以實際案例比較前人與本文提供之公式的優劣，並且證明本文的設計公式之可行性，且有效反映地盤特性對阻尼需求之影響，可作為隔震設計之實務應用中，決定阻尼大小之參考依據。
TitleOptimal Design Formula for Viscous Damping Ratio in Isolation System with Consideration of Site Classification
AuthorCho-Yen Yang,Yang-Chih Fan, Lap-Loi Chung, Bao-Jyun Lu
Keywordsdesign formula, isolation, viscous damping, optimal, site classification
AbstractIn this paper, the optimal viscous damping ratio for isolation system is studied. The linear restoring and damping force are considered. According to the previous literature in optimal design formulas, the white-noise excitation is considered. However, the case analysis in previous study was not doing well because the formulas could not retain the regional feature. Therefore, the numerical analysis intended to input several ground motion records in Taiwan. After that, the rigid and non-rigid superstructures for isolation system with various structure parameters are numerically simulated. The root mean square of absolute structure acceleration is selected to be the objection function for obtaining optimal isolation damping ratio. Repeating the optimal process with various structural parameters, the proposed simple design formula was developed by regression of those optimal isolation damping ratios from numerical simulations. Finally, we conducted the case analysis to verify the feasibility of proposed optimal design formulas.
標題明架式輕鋼架天花板之斜撐組耐震分析及天花板受垂直向地震研究
作者陳威中、姚昭智、林經堯
關鍵字懸吊式輕鋼架天花板、明架式天花板、斜撐組、垂直向地震、振動台實驗
摘要歷年來國內外之地震勘災紀錄可以知道， 在建築物主結構系統尚未發生破壞之情況下，非結構物遭受嚴重破壞的例子很多，而各項非結構物之損壞又以明架式天花板之破壞最為常見。明架式天花板為國內極為普遍之懸吊式天花板系統，卻因缺乏適當之施工方式及耐震措施導致在地震中極容易受到損壞。2011年明架式天花板之耐震施工指南正式收入至「建築物耐震設計規範及解說」之附錄B 中，其中作為抵抗水平地震力之耐震措施即為斜撐組之設置。然而斜撐組之施作一直以來都面臨極大的施工問題，造成許多斜撐組並無法於現場順利組裝，以致於天花板耐震品質參差不齊，影響原訂規範之美意。近年來陸續有研究發現斜撐組並無法有效抵抗地震之作用，甚至有實驗顯示當垂直地震力同時被考慮時反而會加重天花板破壞之情況。為確實瞭解垂直向地震對於明架式天花板之影響以及斜撐組之實際效用，本研究規劃兩階段之全尺寸天花板振動台試驗，試體材料皆符合規範之耐震需求。第一階段天花板試體尺寸為5.7m×2.7m，此階段主要為量測天花板斜撐組在地震中所能負擔之地震力大小，部分試體以單一水平向震波進行測試，其餘天花板試體則同時輸入水平向及垂直向震波。實驗結果發現不論是否考慮垂直向振動，斜撐組中之斜拉線均僅能負擔極少部分之水平作用力（約3%至5%），而當垂直向振動作用於天花板試體時其斜拉線之效用則更為下降。第二階段天花板試體尺寸為7.3m×2.7m， 此階段目的為觀察天花板試體在不同方向地震作用下之破壞模式，實驗結果顯示不論天花板試體是否裝設斜撐組，在單一水平向地震作用下皆有極佳之耐震效果；然而一旦加入垂直向地震力，天花板骨架接頭及骨架收邊處則陸續會出現明顯破壞，甚至在有設置斜撐組之天花板試體中會發現因垂直懸吊線脫落而導致試體發生嚴重崩塌的情形，也說明斜撐組之設計並無法有效提升明架式天花板之耐震能力。本研究依據第二階段實驗數據利用SAP2000 建置明架式天花板電腦模型，首先透過模態分析確認電腦模型之合理性，再以實驗地震紀錄進行動力歷時分析比對電腦模型輸出反應與實驗量測值。完成後之天花板電腦模型可作為後續研究之用模擬各式不同條件明架式天花板之地震動態反應。
TitleSeismic Analysis of Ceiling Lateral Bracing and Vertical Motion Effects on Suspended Ceilings
AuthorGeorge C Yao, Wei-Chung Chen, Ching-Yao Lin
Keywordssuspended ceilings, lateral bracing assembly, bracing wire, shaking table experiment, vertical motion
AbstractPast earthquakes have shown widespread damage to the suspended ceilings. Despite their frequent use in Taiwan, many suspended ceilings experienced damage in earthquakes owing to the lacked proper seismic design or efficient installation. In 2011, Taiwan Building Code issued the seismic installation of the suspended ceiling systems which are similar to the ASTM E580-09. However, the construction of the lateral bracing assembly has always been a difficult challenge. Problems include slack installation or omission of the bracing wires due to obstructions result in uneven quality of the bracing system in-situ. In recent years, some researches have demonstrated that the lateral bracing assembly may not adequately resist the lateral force. The other researches have even shown that unbraced ceiling systems may perform well when providing both sufficient clearance and wide closure. Therefore, there is an increasing concern about the necessity of the bracing system. In order to understand the dynamic behavior of bracing systems of the suspended ceilings, full scale shaking table experiments of suspended ceiling systems were conducted in this study. The first series of experiments on 5.7m × 2.7m ceiling systems looked into the seismic effects of the bracing assemblies. Some ceiling specimens were subjected to unidirectional ground motions while the others were subjected to a horizontal and a vertical ground motions acting together. The results clearly showed that the bracing wire bore only a small portion of the inertial force, and this situation became more obvious while the ceiling systems were subjected to vertical excitations. The second series of experiments on 5.7m × 2.7m ceiling systems compared the seismic performance of the braced and unbraced ceilings. The preliminary observations revealed that the use of the lateral bracing including compression post may not improve the seismic performance of the ceiling system. The unbraced ceiling systems performed well just as the braced ceiling systems when excited only by horizontal ground motions, and it performed better when the vertical ground motions were added to the ceiling systems. In this study, a conceptual computer model was developed based on the experiment data. The accuracy of the computer model was verified by using modal analysis. In comparison with the experiment results, this computer model provides the time-history analysis with reliable accuracy and helps simulate the dynamic response of different conditions of ceiling systems.

Vol.32/No.1 (125) (2017)

作者:

Vol.32/No.1 (125) (2017)

TitleSeismic Behavior of Reinforced Concrete Beams with Rectangular Spiral Reinforcement
AuthorPing-Hsiung Wang, Kuo-Chun Chang, Yu-Chen Ou, Samuel Y. Yin, Jui-Chen Wang, Chih-Hsuan Chen, Chen-Wei Wu
Keywordsrectangular spiral, beam, plastic hinge, cyclic loading
AbstractThis paper presents an experimental study on reinforced concrete beam with continuous rectangular spiral as transverse reinforcement. Three exterior beam-column joint specimens with different beam detailing were devised to exhibit beam hinging and to examine their seismic performance under pseudo-static cyclic loading. Two beams with single and double rectangular spirals were introduced to compare with the one with traditional hoops. Test results show that beam specimen with single rectangular spiral has comparable hysteresis behavior compared to the traditional one, while the one with double rectangular spiral exhibits more degradation due to inadequate detailing at the end of spiral. Without the need of anchored hooks on each hoop, beam with rectangular spiral can save around 25% of transverse reinforcement in comparison with traditional hoops. Moreover, rectangular spiral can be automatically produced and easily erected with less labor effort.
TitleSeismic Tests of High Strength Concrete Filled Box Columns under Large Axial Loads
AuthorChung-Che Chou, Sung-Cheng Wu
KeywordsHigh strength material, Concrete filled box column, High axial load beam-column specimen
AbstractThe cyclic behavior of high strength Concrete Filled Box Column (CFBC) under large axial loads was experimentally investigated. The parameters in the study included the width-to-thickness (b/t) ratio, axial load level and section type. Total six beam-column specimens were tested under a constant axial load and an increasing cyclic loading. The CFBC specimens were 280 to 420 mm in width and 2000 mm in height. Nominal b/t ratios varied from 11 to 30. All specimens were made of high strength steel SM 570M with a nominal yield strength of520~580 MPa.Three specimens were filled with high strength (80 MPa) concrete. Experimental results indicated that ductility decreases significantly with an increase in either axial load level or b/t ratio of the steel. The ductility does not change significantly whether concrete is infilled in the steel box column. Eurocode (EC 2004) and Architectural Institute of Japan (AIJ 2010) have good prediction in the flexural strength of high strength CFBC. AISC-LRFD (2010), ACI 318 (2011) and Taiwan Steel Design Code (2010) are too conservative in predicting the flexural strength of high strength CFBC. All the design codes are conservative in predicting high strength steel column moment capacity, especially for small b/t ratios.
TitlePerformance-based design for earthquake-resistant coupled structural walls
AuthorChung-Chan Hung , Yu-Hsiang Cheng ,Wei-Ting Lu
Keywordscoupled structural walls, performance-based design, nonlinear time-history analysis
AbstractCoupled structural walls are often used in the buildings located in regions with high seismic risk. A coupled wall structure consists of two or more structural walls linked by coupling beams. It is able to provide efficient lateral strength and stiffness, which effectively reduces the drift response of buildings under earthquakes. Current seismic design codes are based on strength methods. Although they are able to prevent structures that are designed accordingly from collapse, the designers and users have limited knowledge about the seismic behavior of the designed structures under different levels of earthquakes. The objective of the present study is to develop a performance-based design method for coupled walls. The developed method allows engineers to pre-select the desirable coupling ratio and performance objectives for coupled walls, and then design the structures accordingly. In addition, it also facilitates the ideal yielding mechanism of coupled walls under earthquakes. Four example coupled wall structures are designed in this study using the proposed method. Their computational models are also built and analyzed using nonlinear time history procedures. The results show that the designed coupled walls are able to exhibit satisfactory structural yielding mechanisms and show the seismic behavior satisfying the pre-selected performance objectives for different seismic hazard levels.
TitleOptimal Design Formula for Viscous Damping Ratio in Isolation System with Consideration of Site Classification
AuthorCho-Yen Yang,Yang-Chih Fan, Lap-Loi Chung, Bao-Jyun Lu
Keywordsdesign formula, isolation, viscous damping, optimal, site classification
AbstractIn this paper, the optimal viscous damping ratio for isolation system is studied. The linear restoring and damping force are considered. According to the previous literature in optimal design formulas, the white-noise excitation is considered. However, the case analysis in previous study was not doing well because the formulas could not retain the regional feature. Therefore, the numerical analysis intended to input several ground motion records in Taiwan. After that, the rigid and non-rigid superstructures for isolation system with various structure parameters are numerically simulated. The root mean square of absolute structure acceleration is selected to be the objection function for obtaining optimal isolation damping ratio. Repeating the optimal process with various structural parameters, the proposed simple design formula was developed by regression of those optimal isolation damping ratios from numerical simulations. Finally, we conducted the case analysis to verify the feasibility of proposed optimal design formulas.
TitleSeismic Analysis of Ceiling Lateral Bracing and Vertical Motion Effects on Suspended Ceilings
AuthorGeorge C Yao, Wei-Chung Chen, Ching-Yao Lin
Keywordssuspended ceilings, lateral bracing assembly, bracing wire, shaking table experiment, vertical motion
AbstractPast earthquakes have shown widespread damage to the suspended ceilings. Despite their frequent use in Taiwan, many suspended ceilings experienced damage in earthquakes owing to the lacked proper seismic design or efficient installation. In 2011, Taiwan Building Code issued the seismic installation of the suspended ceiling systems which are similar to the ASTM E580-09. However, the construction of the lateral bracing assembly has always been a difficult challenge. Problems include slack installation or omission of the bracing wires due to obstructions result in uneven quality of the bracing system in-situ. In recent years, some researches have demonstrated that the lateral bracing assembly may not adequately resist the lateral force. The other researches have even shown that unbraced ceiling systems may perform well when providing both sufficient clearance and wide closure. Therefore, there is an increasing concern about the necessity of the bracing system. In order to understand the dynamic behavior of bracing systems of the suspended ceilings, full scale shaking table experiments of suspended ceiling systems were conducted in this study. The first series of experiments on 5.7m × 2.7m ceiling systems looked into the seismic effects of the bracing assemblies. Some ceiling specimens were subjected to unidirectional ground motions while the others were subjected to a horizontal and a vertical ground motions acting together. The results clearly showed that the bracing wire bore only a small portion of the inertial force, and this situation became more obvious while the ceiling systems were subjected to vertical excitations. The second series of experiments on 5.7m × 2.7m ceiling systems compared the seismic performance of the braced and unbraced ceilings. The preliminary observations revealed that the use of the lateral bracing including compression post may not improve the seismic performance of the ceiling system. The unbraced ceiling systems performed well just as the braced ceiling systems when excited only by horizontal ground motions, and it performed better when the vertical ground motions were added to the ceiling systems. In this study, a conceptual computer model was developed based on the experiment data. The accuracy of the computer model was verified by using modal analysis. In comparison with the experiment results, this computer model provides the time-history analysis with reliable accuracy and helps simulate the dynamic response of different conditions of ceiling systems.

第三十一卷第四期 (期別124) (105年)

作者:

第三十一卷第四期 (期別124) (105年)

標題高強度鋼筋混凝土柱軸力與彎矩強度互制關係電腦程式-NewRC-PM
作者歐昱辰、蔡東均
關鍵字鋼筋混凝土、高強度、柱、軸力與彎矩強度互制關係、New RC、程式
摘要為因應高層鋼筋混凝土建築之強度需求，「台灣新型高強度鋼筋混凝土結構系統(New RC)研發計畫」於是孕育而生，該計畫整合國內產學界之製造與研究能力，致力於發展適用台灣產業環境與設計規範之New RC 結構。該計畫之縱向主筋與橫向鋼筋，分別採用SD690（降伏強度685 MPa）與SD790 之鋼材（降伏強度785 MPa），混凝土抗壓強度一般為70 MPa 以上。為配合台灣NewRC 計畫，本研究發展一套適用NewRC 柱軸力與彎矩強度(PM)互制關係之計算程式：NewRC-PM，並提供免費下載。本文闡述該程式之計算原理，以及與商用PM 互制關係程式之比對驗證。本研究亦蒐集18 組台灣New RC 柱試驗結果，以NewRC-PM 對其進行強度分析，分析結果顯示NewRC-PM 可保守計算所有18 組柱之軸力與彎矩強度。本研究再利用NewRC-PM 進一步分析該18 組柱之最大可能彎矩強度，分析結果顯示混凝土結構設計規範之方法於所有柱皆得不保守之結果；現行橋梁耐震設計規範之方法顯著改善前述不保守之現象，但壓力控制破壞柱仍普遍呈現不保守之預測結果。本研究最終提出最大可能彎矩強度評估方法，與試驗結果比對顯示所提出的方法可提供合理保守之計算結果。
TitleA Computer Program for Axial Load-moment Interaction Diagram for New High-strength Reinforced Concrete Columns- New RC-PM
AuthorYu-Chen Ou, Tung-Chun Tsai
Keywordsreinforced concrete, high strength, columns, axial load-moment interaction diagram, New RC, computer program
AbstractTo address the need for high-rise reinforced concrete buildings in Taiwan, Taiwan New High-Strength Reinforced Concrete (Taiwan New RC) project was initiated. The project integrates the resources of academia and industry of Taiwan to develop the New RC structures for use in Taiwan. The longitudinal and transverse reinforcement used in the project are SD690 (yield strength of 685 MPa) and SD790 (yield strength of 785 MPa), respectively. The concrete compressive strength is typically ≧ 70 MPa. To support the Taiwan New RC project, a computer program, referred to as New RC-PM, was developed in this research to calculate the axial load-moment (PM) interaction diagram for New RC columns as well as for conventional RC columns. The theoretical background and verification of the New RC-PM are presented and discussed in this paper. Moreover, a test database with 18 New RC columns were established. The New RC-PM was used to analyze the PM interaction diagrams of the columns, which were then compared with the test results. The comparison showed that the New RC-PM could conservatively estimate the axial-bending strengths of the columns. The New RC-PM was further used to evaluate the methods for calculating the maximum probable moment strength (Mpr) of the current building and bridge codes. Evaluation results showed that the Mpr calculated by the current building code was unconservative for all the columns. The method of the current bridge code significantly improved the degree of unconservatism of the method of the building code. However, the Mpr was still unconservative for most compression-controlled columns. To address the issue, a new method to calculate the Mpr was proposed in this research. Comparison with the test results showed that the Mpr calculated by the proposed method was reasonably conservative for most of the columns.
標題使用RC 外加構架補強進行結構耐震補強 —以後甲國中德育樓為例
作者林聖學、賴昱志、鍾立來、黃國倫、曾建創、賴濤
關鍵字外加構架補強、耐震補強、側推分析、樓板剪力傳遞
摘要國內在921 大地震後，許多國中、小校舍損壞相當嚴重，但重建相當不經濟且工程亦相當浩大，故多數選擇採取補強方式，然國內目前常見的補強方式（例如：擴柱補強、翼牆補強及剪力牆補強）皆會影響到結構內部的運作，故本研究提出國內目前較少見之外加構架補強方法，該補強方式不影響結構物本身之運作功能，初步先以校舍進行研究探討此補強工法之可行性，未來可望將此方法推展至內部功能不能停止運作之建築物（例如：醫院）。本研究以後甲國中德育樓進行補強之模擬，以樓板將既有建物與外加構架連接，並進行側推分析，最後進行樓板剪力傳遞之檢核，確認樓板能夠完全將地震力由既有構架傳遞至外加構架，確保此方法之合理性，由設計實例確認本研究所提方法確實能夠提升低矮型校舍之耐震能力。
TitleSeismic Retrofit by External Reinforced Concrete Frames – Using School Building of HOU-JIA Junior High School as Example
AuthorSheng-Hsueh Lin, Yu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Chien-Chuang Tseng
Keywordsretrofit by external frames, seismic retrofit, pushover analysis, shear capacity of slab
AbstractIn Chi-Chi earthquake, the school buildings in Taiwan were damaged seriously. Because rebuilding school buildings will be uneconomical and that will be a tremendous amount of work, seismic retrofit methods are usually adopted to raise seismic performance of buildings. The typical retrofit methods of school buildings in Taiwan include RC jacketing, wing wall and shear wall etc. However, those methods above will affect the function of the existing building during the construction. In this paper, retrofit method with adding external frames, seldom seen in Taiwan, is proposed. The advantage of this method is that the function of the existing building will not be affectedduring the construction. We first use a school building to discuss the feasibility of the method. And it is suggested that the method can be used on the buildings whose functioncannot be affected during construction, such as hospitals. We use a school building of HOU-JIA junior high school to apply a retrofit design of this seismic retrofit method using slabs to connect existing building and external frames. After the retrofit design, we do pushover analysis to make sure the seismic capacity of the retrofitted school building is enough. Finally, we check the shear capacities of slabs to make sure they can completely transfer the earthquake load from the existing building to external frames. By the design example, we prove that the retrofit method of RC external frame is fit to the common squat school buildings.
標題大尺寸BCR 鋼管柱的耐震性能
作者陳正誠、林書豪、吳品達
關鍵字冷軋鋼管、鋼結構、鋼管柱、耐震設計
摘要本文針對大尺寸冷軋方形鋼管柱之韌性發展，以5 支全尺寸試體之反復載重試驗探討之。試體包括裂縫敏感試體及局部挫屈敏感試體，此外採用內藏式橫隔板及外橫隔板工法，進行梁與柱之連接。研究結果發現：（1）冷軋過程對鋼管斷面產生可觀的塑性應變，然而控制梁與柱間銲道施工之銲接入熱量，包括斷面直線段在40 KJ/cm 以內、斷面角隅段在30 KJ/cm 以內，可以避免裂縫過早發生；（2）鋼管柱斷面的寬厚比為10.9 時，試體之容許層間位移角可達7%以上，塑性轉角容量可達4.5%以上；（3）鋼管柱斷面的寬厚比為23.9 時，雖然比規範規定之15.6 大很多，但是試體之容許層間位移角仍可達4.2~4.4%，塑性轉角容量亦有2.1~2.2%，大致可符合耐震之需求；（4）規範對鋼管柱寬厚比限制比箱型柱嚴格，但是試驗結果顯示在相同的斷面寬度及柱板厚度下，兩者的韌性行為頗為類似。
TitleSeismic Performance of Large BCR Steel Columns
AuthorCheng-Cheng Chen, Shu-Hao Lin, Pin-Da Wu
Keywordscold formed structural tube, steel structure, steel column, earthquake-resistant structures
AbstractThis study examined the ductility development of large cold-formed square tube columns through cyclic loading test of five full-sized specimens. Specimens included crack-sensitive and local-buckling-sensitive specimens. In addition, specimens using internal diaphragm and external diaphragm were employed to weld the columns to the beams. Based on the test results, the following conclusions can be drawn: (1) The cold-forming process caused considerable plastic strain on the cross sections of the steel columns, however, by controlling the heat input in the welding passes, premature cracks can then be suppressed. (2) For the specimens with a column wall width-to-thickness ratio equals to 10.9, a story drifty ratio capacity no less than 7% and a plastic hinge rotation capacity no lower than 4.5% can be reached. (3) For the specimens with a column wall width-to-thickness ratio of 23.9, which is much larger the code limitation of 15.6, a story drift ratio capacity between 4.2%–4.4% and a plastic hinge rotation capacity between 2.1%–2.2% can be reached; generally, the specimens satisfied the requirements for seismic structures. (4) Although a more restrict with-to-thickness ratio for cold-formed square section than for box column is specified by the code, the ductility of the structural tube and the box column with the same section width and wall thickness is similar.
標題黏性阻尼器應用於二維與三維建築結構 之最佳化設計
作者詹鵬台、鄭至伸、呂良正
關鍵字黏性阻尼器、阻尼器最佳化配置、剪力構架、三維不對稱建築結構
摘要近年來，被動消能裝置已被廣泛的應用於建築結構中，然而在現行的規範當中，如FEMA273/274 僅提供工程師黏性阻尼器等效阻尼比設計之建議，但更有效益的阻尼器最佳化設計卻鮮少被提及。儘管有些阻尼器最佳配置方法已被提出，但這些最佳化方法往往夾帶著繁瑣且複雜的計算，較難以被實際工程界所接受及使用。為克服此一限制，本研究主要是利用較為簡單且同時兼具理想抗震效益的方法以設計黏性阻尼器之最佳化配置。本文提出新的配置方法，用以將阻尼消能向上提升以增進結構物抵抗地震力。本文將不同的阻尼最佳化配置方法應用於剪力構架以及三維不對稱結構中，利用多筆符合設計反應譜的人造地震歷時對這些方法做檢核。最後，以統計工具來探討各種方法應用於不同建築結構之適用性。
TitleOptimal Design of Viscous Dampers for Two and Three-Dimensional Building Structures
AuthorPeng-Tai Chan, Chih-Shen Cheng, Liang-Jenq Leu
KeywordsViscous dampers, optimal placement of dampers, shear type buildings, three-dimensional asymmetric buildings
AbstractNowadays, passive energy dissipation devices are widely used in building structures. Design codes such as FEMA273/274 suggested that the equivalent damping ratio of supplemental viscous dampers be used. However, how to place viscous dampers optimally was not addressed. Several optimal damper placement methods have been proposed to improve the seismic performance of structures but they usually involve complicated procedure and therefore are not suitable for practical applications. The goal of this study is aimed at finding the optimal placement of viscous dampers using proposed simple methods. The proposed methods and other optimal damper placement methods are applied to different shear type buildings and a three-dimensional asymmetric building. Their performance and applicability are compared using statistical methods under a series of spectrum-compatible ground motions.
標題雙向單擺型調諧質量阻尼器之減振效益分析
作者章靖、廖偉汝、連冠華、鍾立來、賴勇安、曾建創
關鍵字調諧質量阻尼器、雙向分析、風力減振、高樓結構
摘要調諧質量阻尼器(Tuned Mass Damper, TMD)已成功應用在許多高樓建築中並有效抑制風力引致之振動。一般TMD 減振效益分析，主要是針對欲調諧的建築物於某振態在加裝TMD 後，分析其減振效果。模態分析雖簡易，但為單向分析，人們所感受到的舒適程度是以雙向之合加速度來判定，因此模態分析需再配合和方根(Square Root of the Sum of the Squares, SRSS)等方式求得約略之最大合加速度。如直接進行雙向動力分析將會比起單向分析更加直接、適當且準確。此外，如TMD 的阻尼器在空間中斜向放置，則阻尼器提供之阻尼力將雙向耦合。因此，本文除了建立出雙向單擺型TMD加裝於剪力屋架上之分析程序外，並針對空間中斜向放置的阻尼器，推導其阻尼力，進行雙方向的減振效益分析。最後，以一高樓案例進行減振效益分析說明，作為工程業界參考之用。縱然TMD 之阻尼器是斜向安裝，只要對稱配置，耦合之阻尼矩陣，亦能去耦而僅為對角矩陣，即雙向之阻尼力可去耦而不相互影響。只要結構雙向之振動週期夠接近，單擺型TMD 即具雙向減振之功能，在1 年回歸期之風力下，合加速度下降至舒適度之要求；在50 年回歸期之風力下，雙向之基底剪力的減幅，滿足規格之要求。此外，TMD 之阻尼器採斜向配置，可有效降低阻尼器衝程之需求。
TitleEffect of Vibration Reduction of Bidirectional Suspension-type Tuned Mass Damper
AuthorJing Jhang, Wei-Ru Liao, Yong-An Lai, Kuan-Hua Lien, Lap-Loi Chung, Chien-Chuang Tseng
KeywordsTuned Mass Damper, bidirectional analysis, wind-induced vibration control, high-rise building
AbstractThe tuned mass damper (TMD) is widely utilized for civil engineering to control wind-induced vibration in high-rise building. In this research, the design and analysis procedures of the bidirectional suspension-type tuned mass damper are proposed and demonstrated. The main structure is simplified as a shear building model to install the suspension-type tuned mass damper for simulation by the dynamic time history analysis. For common pendulum tuned mass damper, the suspension position and viscous damper implement location are located at different floors. Therefore the reaction force and damping force of the tuned mass damper are acting on different degrees of freedom of the main structure. Although the damping force of a damper is acting in both the two horizontal directions because the damper is implemented with an angle to the floor plane, the damping force is independent in the two horizontal directions if the dampers are allocated in symmetric layout. Therefore, the damping matrix can be decoupled. The feasibility of the bidirectional suspension-type tuned mass damper is illustrated by the high-rise building subjected to the design wind force with return periods of 1 year and 50 years, respectively. Following numerical verification, the effects of vibration reduction for the high-rise building subjected to the design wind forces are demonstrated.
標題以微振法量測斜張鋼纜索力之目標頻率選用
作者吳文華、陳建州、王乙任
關鍵字斜張鋼纜、索力、微振法、振態頻率、錨定系統
摘要工程界用於量測斜張鋼纜索力通常以微振法為主，而為提升索力量測的精度，鋼纜振態頻率的精準選用乃是必要條件。基本上鋼纜之各相鄰振態頻率多接近等間距而不難識別，不過卻可能受到橋體頻率、錨定系統偏向束制以及錨定系統局部振動等因素之干擾而產生混淆，特別在鋼纜長度較短時尤為顯著。本文因此針對由鋼纜訊號所可能識別出的頻率，就其種類與來源進行深入分析，從而希望解決鋼纜振態頻率識別實務上的困難以提升後續索力分析之精度。首先對於橋體頻率交叉混雜的問題，建議宜進行廣泛頻率範圍的識別，然後根據較高階鋼纜振態頻率的近似等間距關係，便容易排除橋體振態頻率在低頻範圍的干擾。其次，如鋼纜因錨定系統前端橡膠套環的偏向束制導致各振態都同時存在一對相當接近的頻率時，需特別注意後續分析最好在不同振態都固定選用數值較低或數值較高的一組，如此索力之計算才能具有共同的邊界束制基礎。至於若因鋼纜與錨定子系統相互耦合而使得振態頻率在特定範圍內出現不規則分岔時，則應謹慎篩選出其他明顯不受耦合影響的鋼纜振態頻率，俾能精確評估索力。
TitleSelection of modal frequencies adopted in ambient vibration method for determination of stay cable force
AuthorWen-Hwa Wu, Chien-Chou Chen, Yi-Ren Wang
Keywordsstay cable, cable force, ambient vibration method, modal frequency, anchorage system
AbstractThe ambient vibration method is typically employed in engineering practice to determine the tension of a stay cable and its precision strongly depends on the appropriate selection of cable frequencies. In general, the modal frequencies of a stay cable are close to an arithmetic sequence and these well separated frequency values are not difficult to be identified. From recent measurements on different stay cables by this research group, however, it is found that the identification of cable frequencies is possibly disturbed by the frequencies of bridge deck, the biased constraint of anchorage system, and the coupled interaction for the cable with its anchorage system. This study is consequently aimed to systematically explore these three types of difficulties such that the goal of clarified cable frequency identification and accurate cable force estimation can be attained. For the confusion caused by the frequencies of bridge deck, it is suggested to conduct the cable frequency identification over a wider frequency range and then exclude the interference of the deck frequencies in the lower frequency range based on the equally spaced relationship of cable frequencies conveniently observed in the higher frequency range. Regarding the biased constraint of anchorage system to induce a pair of frequencies for each vibration mode, it is recommended to consistently adopt the higher or lower frequency value in each pair for the computation of cable force established on a basis of common boundary constraints. Finally, the phenomenon that a particularcable frequency within a specific frequency range can irregularly splitinto two is confirmed to result from the coupled interaction between the cable and its anchorage system. Under such circumstances, special attention should be paid to choose the cable frequencies not influenced by this coupling for evaluating the cable tension.

Vol.31/No.4 (124) (2016)

作者:

Vol.31/No.4 (124) (2016)

TitleA Computer Program for Axial Load-moment Interaction Diagram for New High-strength Reinforced Concrete Columns- New RC-PM
AuthorYu-Chen Ou, Tung-Chun Tsai
Keywordsreinforced concrete, high strength, columns, axial load-moment interaction diagram, New RC, computer program
AbstractTo address the need for high-rise reinforced concrete buildings in Taiwan, Taiwan New High-Strength Reinforced Concrete (Taiwan New RC) project was initiated. The project integrates the resources of academia and industry of Taiwan to develop the New RC structures for use in Taiwan. The longitudinal and transverse reinforcement used in the project are SD690 (yield strength of 685 MPa) and SD790 (yield strength of 785 MPa), respectively. The concrete compressive strength is typically ≧ 70 MPa. To support the Taiwan New RC project, a computer program, referred to as New RC-PM, was developed in this research to calculate the axial load-moment (PM) interaction diagram for New RC columns as well as for conventional RC columns. The theoretical background and verification of the New RC-PM are presented and discussed in this paper. Moreover, a test database with 18 New RC columns were established. The New RC-PM was used to analyze the PM interaction diagrams of the columns, which were then compared with the test results. The comparison showed that the New RC-PM could conservatively estimate the axial-bending strengths of the columns. The New RC-PM was further used to evaluate the methods for calculating the maximum probable moment strength (Mpr) of the current building and bridge codes. Evaluation results showed that the Mpr calculated by the current building code was unconservative for all the columns. The method of the current bridge code significantly improved the degree of unconservatism of the method of the building code. However, the Mpr was still unconservative for most compression-controlled columns. To address the issue, a new method to calculate the Mpr was proposed in this research. Comparison with the test results showed that the Mpr calculated by the proposed method was reasonably conservative for most of the columns.
TitleSeismic Retrofit by External Reinforced Concrete Frames – Using School Building of HOU-JIA Junior High School as Example
AuthorSheng-Hsueh Lin, Yu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Chien-Chuang Tseng
Keywordsretrofit by external frames, seismic retrofit, pushover analysis, shear capacity of slab
AbstractIn Chi-Chi earthquake, the school buildings in Taiwan were damaged seriously. Because rebuilding school buildings will be uneconomical and that will be a tremendous amount of work, seismic retrofit methods are usually adopted to raise seismic performance of buildings. The typical retrofit methods of school buildings in Taiwan include RC jacketing, wing wall and shear wall etc. However, those methods above will affect the function of the existing building during the construction. In this paper, retrofit method with adding external frames, seldom seen in Taiwan, is proposed. The advantage of this method is that the function of the existing building will not be affectedduring the construction. We first use a school building to discuss the feasibility of the method. And it is suggested that the method can be used on the buildings whose functioncannot be affected during construction, such as hospitals. We use a school building of HOU-JIA junior high school to apply a retrofit design of this seismic retrofit method using slabs to connect existing building and external frames. After the retrofit design, we do pushover analysis to make sure the seismic capacity of the retrofitted school building is enough. Finally, we check the shear capacities of slabs to make sure they can completely transfer the earthquake load from the existing building to external frames. By the design example, we prove that the retrofit method of RC external frame is fit to the common squat school buildings.
TitleSeismic Performance of Large BCR Steel Columns
AuthorCheng-Cheng Chen, Shu-Hao Lin, Pin-Da Wu
Keywordscold formed structural tube, steel structure, steel column, earthquake-resistant structures
AbstractThis study examined the ductility development of large cold-formed square tube columns through cyclic loading test of five full-sized specimens. Specimens included crack-sensitive and local-buckling-sensitive specimens. In addition, specimens using internal diaphragm and external diaphragm were employed to weld the columns to the beams. Based on the test results, the following conclusions can be drawn: (1) The cold-forming process caused considerable plastic strain on the cross sections of the steel columns, however, by controlling the heat input in the welding passes, premature cracks can then be suppressed. (2) For the specimens with a column wall width-to-thickness ratio equals to 10.9, a story drifty ratio capacity no less than 7% and a plastic hinge rotation capacity no lower than 4.5% can be reached. (3) For the specimens with a column wall width-to-thickness ratio of 23.9, which is much larger the code limitation of 15.6, a story drift ratio capacity between 4.2%–4.4% and a plastic hinge rotation capacity between 2.1%–2.2% can be reached; generally, the specimens satisfied the requirements for seismic structures. (4) Although a more restrict with-to-thickness ratio for cold-formed square section than for box column is specified by the code, the ductility of the structural tube and the box column with the same section width and wall thickness is similar.
TitleOptimal Design of Viscous Dampers for Two and Three-Dimensional Building Structures
AuthorPeng-Tai Chan, Chih-Shen Cheng, Liang-Jenq Leu
KeywordsViscous dampers, optimal placement of dampers, shear type buildings, three-dimensional asymmetric buildings
AbstractNowadays, passive energy dissipation devices are widely used in building structures. Design codes such as FEMA273/274 suggested that the equivalent damping ratio of supplemental viscous dampers be used. However, how to place viscous dampers optimally was not addressed. Several optimal damper placement methods have been proposed to improve the seismic performance of structures but they usually involve complicated procedure and therefore are not suitable for practical applications. The goal of this study is aimed at finding the optimal placement of viscous dampers using proposed simple methods. The proposed methods and other optimal damper placement methods are applied to different shear type buildings and a three-dimensional asymmetric building. Their performance and applicability are compared using statistical methods under a series of spectrum-compatible ground motions.
TitleEffect of Vibration Reduction of Bidirectional Suspension-type Tuned Mass Damper
AuthorJing Jhang, Wei-Ru Liao, Yong-An Lai, Kuan-Hua Lien, Lap-Loi Chung, Chien-Chuang Tseng
KeywordsTuned Mass Damper, bidirectional analysis, wind-induced vibration control, high-rise building
AbstractThe tuned mass damper (TMD) is widely utilized for civil engineering to control wind-induced vibration in high-rise building. In this research, the design and analysis procedures of the bidirectional suspension-type tuned mass damper are proposed and demonstrated. The main structure is simplified as a shear building model to install the suspension-type tuned mass damper for simulation by the dynamic time history analysis. For common pendulum tuned mass damper, the suspension position and viscous damper implement location are located at different floors. Therefore the reaction force and damping force of the tuned mass damper are acting on different degrees of freedom of the main structure. Although the damping force of a damper is acting in both the two horizontal directions because the damper is implemented with an angle to the floor plane, the damping force is independent in the two horizontal directions if the dampers are allocated in symmetric layout. Therefore, the damping matrix can be decoupled. The feasibility of the bidirectional suspension-type tuned mass damper is illustrated by the high-rise building subjected to the design wind force with return periods of 1 year and 50 years, respectively. Following numerical verification, the effects of vibration reduction for the high-rise building subjected to the design wind forces are demonstrated.
TitleSelection of modal frequencies adopted in ambient vibration method for determination of stay cable force
AuthorWen-Hwa Wu, Chien-Chou Chen, Yi-Ren Wang
Keywordsstay cable, cable force, ambient vibration method, modal frequency, anchorage system
AbstractThe ambient vibration method is typically employed in engineering practice to determine the tension of a stay cable and its precision strongly depends on the appropriate selection of cable frequencies. In general, the modal frequencies of a stay cable are close to an arithmetic sequence and these well separated frequency values are not difficult to be identified. From recent measurements on different stay cables by this research group, however, it is found that the identification of cable frequencies is possibly disturbed by the frequencies of bridge deck, the biased constraint of anchorage system, and the coupled interaction for the cable with its anchorage system. This study is consequently aimed to systematically explore these three types of difficulties such that the goal of clarified cable frequency identification and accurate cable force estimation can be attained. For the confusion caused by the frequencies of bridge deck, it is suggested to conduct the cable frequency identification over a wider frequency range and then exclude the interference of the deck frequencies in the lower frequency range based on the equally spaced relationship of cable frequencies conveniently observed in the higher frequency range. Regarding the biased constraint of anchorage system to induce a pair of frequencies for each vibration mode, it is recommended to consistently adopt the higher or lower frequency value in each pair for the computation of cable force established on a basis of common boundary constraints. Finally, the phenomenon that a particularcable frequency within a specific frequency range can irregularly splitinto two is confirmed to result from the coupled interaction between the cable and its anchorage system. Under such circumstances, special attention should be paid to choose the cable frequencies not influenced by this coupling for evaluating the cable tension.

第三十一卷第三期 (期別123) (105年)

作者:

第三十一卷第三期 (期別123) (105年)

標題台灣混凝土彈性模數建議公式研究
作者廖文正、林致淳、詹穎雯
關鍵字混凝土、彈性模數、粒料、抗壓強度
摘要混凝土為由水泥、水及粗細粒料所組成之複合材料，故其彈性模數高低受組成材料等因素影響甚鉅。關於混凝土彈性模數的計算，台灣主要是參照內政部營建署頒佈之「混凝土結構設計規範」，其公式內容是根據美國混凝土學會ACI 318 而定；但從以往研究發現，台灣相較於美國的混凝土彈性模數有明顯偏低的趨勢。有鑑於混凝土彈性模數在工程設計應用上的重要性，以及近年添加高摻量飛灰、水淬高爐爐碴粉等卜作嵐摻料的高性能混凝土被廣泛地使用，本研究乃從混凝土的組成出發，探討影響彈性模數之因子，而後針對台灣本土混凝土材料，蒐集台灣學術機構及現地試驗之彈性模數資料，進行統計迴歸與分析。根據研究成果，本研究建議將ACI318 之彈性模數預測公式乘上一修正因子0.8，適用範圍為抗壓強度在210kgf/cm2~840 kgf/cm2 間之混凝土，除了易於業界計算外，並可反映台灣混凝土彈性模數偏低的事實，並做為未來工程規範修訂的參考。
TitleA Practical Equation for Elastic Modulus of Concrete in Taiwan
AuthorW.-C. Liao, C.-C. Lin, Y.-W. Chan
KeywordsConcrete, Elastic Modulus, Aggregate, Compressive Strength
AbstractConcrete is a composite material consisting of water, cement, fine and coarse aggregates. The elastic modulus of concrete is highly affected by the properties of its components. The estimation of elastic modulus of concrete in Taiwan is mainly referred to the empirical equation provided in America Concrete Institute, ACI 318. However, it can be found that the elastic modulus of concrete in Taiwan is considerably lower than that in US according to the experimental results due to differences of aggregate properties. The aggregate phase is predominantly accounted for the elastic modulus of concrete. In addition, notable amounts of pozzolanic materials, such as fly ash and slag, are widely used in concrete mixtures in Taiwan. Since the elastic modulus directly influences the stiffness of RC structures, a more accurate prediction of the elastic modulus of concrete in Taiwan to reflect all these characteristics is essential. This paper proposes a formula to estimate the elastic modulus of concrete in Taiwan by collecting and analyzing the related test data. The parametric analysis is also carried out to verify the validity of this formula. This practical formula of elastic modulus of concrete has good agreement with that obtained from the experiments.
標題以性能為導向之二階段隔震設計法
作者盧煉元、王亮偉、陳慶輝、李官峰、李姿瑩、蔡諄昶
關鍵字 
摘要結構隔震技術為近年來發展極為快速的耐震新技術之一，可大幅提升結構之耐震性能，我國目前已有隔震設計規範可供依循。不過，現行隔震規範僅提供通用之公式，可用以決定總體隔震系統參數，但並無法用以設計個別隔震支承之參數。因此，傳統隔震設計流程係工程師依經驗選擇隔震支承參數，再利用規範公式進行隔震結構之設計，由於隔震支承大多為非線性元件，若設計結果未能滿足耐震需求，則必須經過多次重複的試誤及迭代過程，方能完成設計並決定隔震支承之參數。為簡化設計流程，本文乃提出「以性能為導向之二階段隔震設計法」。此法以不超過最大容許上傳地震力與容許隔震位移作為雙重性能目標，在無需迭代的情況下，即可決定出滿足此二項性能目標之隔震支承參數。本文方法主要分為二個設計階段，第一階段為線性隔震設計，主要係在滿足預設性能目標條件下利用規範公式以決定線性化等效隔震系統參數，亦即：有效週期與有效阻尼。而第二階段為非線性隔震設計，主要是由第一階段所得之線性化系統參數推求個別隔震器之非線性支承參數，例如：LRB 支承之降伏後勁度及降伏強度等。為方便實務之應用，文中詳細推導各階段所需之輔助設計用公式，同時亦列出詳細之設計流程及步驟。文末更以之一棟含有LRB 隔震支承之五層樓RC 建物為案例，以示範如何應用本文建議之設計方法及流程，在無需迭代及試誤計算的情況下獲得個別LRB 之支承參數，此組參數並可同時滿足預設之雙重性能目標。
TitlePerformance-oriented two-stage design method for base-isolated structures
AuthorLyan-Ywan Lu, Liang-Wei Wang, Ching-Huei Chen, Kuan Feng Lee, Tzu-Ying Lee, Chun-Chung Tsai
Keywordsbase isolation, isolation design, performance objective, allowable isolator displacement, allowable base shear
AbstractBase isolation is an effective means for improving seismic resistance capacity of structures. Design codes for base isolation have been given in many countries for many years. However, most of existing codes only provide generic formulas that determine the parameters of an isolation system as a whole, rather than the parameters for individual isolators. Consequently, design engineers have to perform the design task based on the isolator parameters selected according to past experience. Moreover, since most of existing isolators are nonlinear devices, conventional design methods usually involve iteration and trial-and-error procedure if certain performance demand has to be satisfied. In order to simplify the design procedure so the tedious iteration procedure in a conventional design approach can be averted, in this paper, a performance-oriented two-stage design method is proposed. Without iteration, this method is able to determine a set of isolator parameters that meet the two pre-selected performance objectives, namely, the allowable isolator displacement and base shear. The proposed method includes two design stages. In the first stage, the formulas specified in the current design code are employed to compute the linearized parameters of the whole isolation system, i.e., the effective period and effective damping, so that the two performance objectives can be satisfied. Based on the linearized parameters determined in the first stage, in the second stage, the nonlinear parameters for each individual isolator, such as the yield force and post-yield stiffness in a LRB isolator, are computed. For the convenience of applications, in this work, the complementary design formulas are derived and design steps are also outlined. Finally, the feasibility of the proposed design method is demonstrated by an example that involves a 5-story RC building isolated by LRB isolators.
標題採最佳化摩擦係數設計公式之隔震實務設計流程
作者王勝宣、蔡易佑、鍾立來、楊卓諺、高培修
關鍵字鋼筋混凝土、開孔牆、側力位移曲線、剪力強度、剪力變形
摘要由耐震設計中反應譜的觀念得知，當結構系統之週期較長時，有較低之設計地震力。隔震系統乃呼應此觀念，藉由延長結構系統之週期來降低上傳之水平地震力。摩擦係數在摩擦消能隔震系統扮演相當重要的角色。摩擦係數過低或過高，皆會提高上傳之地震力，隔震層設計位移則是隨著摩擦係數提高而降低，因此摩擦係數之決定相當重要。然而，目前業界通常是仰賴經驗以決定摩擦係數，而非一套有系統之方法。此外，由於地震震度與震波形式之不確定性，結構物於使用年限之間有可能碰到尖峰地表加速度(peak ground acceleration, PGA)更甚於設計地震之大地震，或是具低頻特性之近斷層震波。因此，本文嘗試將本文作者所發表之摩擦係數最佳化公式融入業界習用之隔震設計流程，是為摩擦係數最佳化隔震設計流程。為驗證最佳化流程之效果，本文考慮一假想隔震案例，並以設計地震、1.5倍設計地震、近斷層地震當作輸入，執行歷時分析，來驗證隔震效果及隔震層位移是否超過隔震位移限制。分析結果顯示，最佳化設計流程於三種外力下皆能有效降低加速度反應，但當外力為非設計地震力時，位移反應可能會超過隔震位移限制，代表最佳化流程可能無法滿足需求，因此本文嘗試改變設計流程之邏輯。首先固定位移，而後直接代入非設計地震之反應譜係數進行設計，此為修正最佳化隔震設計流程。本文亦以假想隔震案例進行設計，再以非設計地震力當作輸入執行歷時分析。由模擬結果可知此修正設計流程具有不錯的減震效果，隔震層最大位移反應亦小於隔震位移限制。摩擦係數最佳化設計流程相對於業界現行之設計流程僅多增加一步驟，並不會大幅影響工程師之設計習慣，但卻能作為工程師選用參數的依據。而修正最佳化隔震設計不僅步驟簡潔且又針對非設計地震需求設計，故本文認為此流程可以信賴。
TitleStructural Isolation Design Procedure with Optimal Design Formula of Friction Coefficient
AuthorSheng-Hsuan Wang, Yi-YoTsai, Lap-Loi Chung, Cho-Yen Yang, Pei-Shiou Kao
Keywordsisolation systems, frictional coefficient, optimal design procedure, isolation systems simulation
AbstractAccording to the concept of earthquake response spectrum, the structure which equips with isolation system reduces seismicforce by extending the period.For isolation design, the friction coefficient is one of the main design parameters. Based on the experience, the isolation displacement get lower with larger friction coefficient, however, the structural acceleration get larger with lower or larger friction coefficient.In the conventional isolation design procedures, the energy dissipation parameters, like friction coefficient, is not determined by some certain criteria but engineers’ practical experience. Because structure may suffer nearfult earthquake orearthquake of which intensity is larger than design earthquake. This article incorporates the optimal friction coefficient into isolation design process which called optimalisolation design process of friction coefficient. In order to verify effect of the process, the article choosesdesign earthquake, 1.5 times design earthquake and nearfult earthquake as input to do time history analysis in an imaginary case. The simulation result indicates that structural acceleration reduce effectively but isolation displacement may be larger than displacement limit except under design earthquake. Therefore, the article change design logicthat fixes displacement first and designs with non-design earthquake response spectrumto develop modified optimal isolation design process and chooses non-design earthquake as input to do the timehistory analysis in an imaginary case.According to the analysis results, the isolation displacement will be lower than design displacement andstructuralacceleration reduce effectively. Because the difference between the optimal design procedures of friction coefficient and the conventional one is insignificant, engineers will feel comfortable to adopt the optimal design procedures to determine isolation parameter. The modified optimal isolation process’s steps are concise and base on non-design earthquakeresponse spectrum, so the article refer the process as credible.
標題鋼筋混凝土開孔牆受剪破壞之側力位移曲線預測
作者黃世建、林永健、蔡仁傑、曾建創、涂耀賢、蕭輔沛
關鍵字鋼筋混凝土、開孔牆、側力位移曲線、剪力強度、剪力變形
摘要低矮型鋼筋混凝土(Reinforced Concrete; RC)住宅建築使用了大量的開孔RC 牆，但由於工程界對開孔RC 牆之耐震行為不甚了解，故於耐震評估與設計時，常將開孔RC 牆之貢獻予以忽略或是過度折減使用。此將造成住宅建築之耐震能力被嚴重低估，這對低矮型住宅結構之耐震設計、評估與補強工作有不利之影響。本文對開孔RC 牆在剪力破壞控制下之側力位移曲線提出建議，其係以開裂點、強度點及崩塌點為轉折之曲線。經與反復載重之開孔RC 牆實驗比對，得知本文建議之側力位移曲線，確實能合理反映開孔RC 牆之耐震行為。本文建議的分析程序已大幅簡化，可以手算執行，非常適合工程實務之應用。若對低矮型RC 建築執行側推分析，而將開孔RC 牆模擬為等值寬柱時，本文建議之側力位移曲線，可供該寬柱剪力塑鉸之模擬使用。
TitlePrediction of Lateral Load Displacement Curve of RC Wall with Openings Failing in Shear
AuthorShyh-Jiann Hwang, Weng-Kin Lam, Ren-Jie Tsai, Chien-Chuang Tseng, Yaw-Shen Tu, Fu-Pei Hsiao
Keywordslateral load displacement curve, reinforced concrete, shear deformation, shear strength, wall with opening
AbstractThere are plenty of RC walls with openings in the low-rise residential buildings. Due to unawareness of the behavior of RC walls with openings, their effects are often ignored or undervalued during seismic assessment and design. In consequence, the seismic capacity of residential buildings is greatly underestimated, which is detrimental to the work of seismic design, evaluation and retrofitting for the low-rise residential buildings. In this paper, a lateral load displacemen tcurve of the RC walls with openings subjected to shear failure is proposed. The turning points in the structural behavior are defined as shear cracking, shear strength and collapse point. The proposed model correlates well with the available test results of RC walls with openings. Calculations of the proposed model are greatly simplified to fit in the purpose of design in practice. For the pushover analysis, the proposed model can simulate the properties of shear plastic hinge of the RC walls with openings.
標題不同橋梁耐震評估方法之比較
作者黃仲偉、洪曉慧、陳常麒
關鍵字性能設計、側推分析、多跨橋梁、動力歷時、耐震評估
摘要結構的「耐震設計」與「耐震評估」長久以來一直是國內推廣永續發展之重大課題，歐、美、日本在內的許多國家皆已採用性能設計理念的精神與內涵於新世紀技術規範。國內亦於民國98 年起推動本土化公路橋梁耐震性能設計規範，目標為控制橋梁結構於各等級地震作用下之使用性、可修復性與安全性。確保新建橋梁在不同等級地震作用下達到預期耐震設計目標之可靠度，降低橋梁地震中的受損風險。本文旨在介紹公路橋梁耐震能力設計規範草案中的耐震評估方法，並以四座多跨連續數值橋梁為探討對象。利用非線性側推分析建立橋梁整體容量曲線，分別以不同的耐震評估方法計算橋梁性能點，由性能點反推橋梁上部結構整體之側向位移。最後以非線性動力歷時分析所得之橋梁上部結構整體之側向位移作為基準，比較不同耐震評估方式所得結果的差異。希冀透過此研究可讓國內實務單位對於不同橋梁耐震評估方法能有初步的認識。
TitleComparison of different bridge seismic assessment methods
AuthorChang-Wei Huang, Hsiao-Hui Hung, Chang-Chi Chen
Keywordsperformance design, pushover analysis, multiple span bridge, dynamic time history,seismic assessment
AbstractStructural seismic design and seismic assessment are important issues in the sustainable development. Today, the concepts of performance-based design have been adopted in the building codes of European Union, Untied of States, Japan and other advanced countries. As a result, the performance-based seismic design provisions and commentary for highway bridges has also been introduced in Taiwan from 2009. The aims of the new seismic design provisions are to ensure the serviceability, retrofit, and safety of highway bridges under seismic hazards. In addition, the new seismic design provisions focus on the real responses of structures suffer from different levels of earthquakes, which can guarantee the new bridges, according to the performance-based design, achieving the reliability of anticipated targets and decreasing the damage ricks. In this paper, the draft of the new seismic design provisions for highway bridges is introduced and compared with other two existed method (ATC-40 and refined seismic assessment method). Pushover analyses with uniform lateral load pattern for four numerical multiple-span bridges are carried out. Then the pushover curves are transformed to the corresponding capacity spectrum curve with multiple monitoring points. Then the performance points are obtained by three seismic assessment methods and can be used to estimate the maximum lateral displacements. Compared with the results from nonlinear dynamic analyses, one can know the differences between three seismic assessment methods.