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.