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Vol.34/No.1 (133) (2019)

作者:

Vol.34/No.1 (133) (2019)

Title Seismic design and analysis on boundary elements in bidirectional steel plate shear walls
Author Yi-Hsuan Yang, Tung Huang, Chao-Hsien Li, Ching-Yi Tsai, Keh-Chyuan Tsai
Keywords bi-directional steel plate shear walls, capacity design, axial, shear and flexural interaction, finite element model analysis, composite beam
Abstract The aim of this research is to propose a seismic design method for the corner vertical boundary elements (VBEs) in bidirectional steel plate shear walls (SPSWs) through a series of analytical and experimental studies. The VBEs at the intersection of bidirectional SPSWs must sustain the force demands induced from the two SPSWs simultaneously. The column axial force, bi-directional moments and shears are incorporated in the proposed procedures in computing the reduced column flexural capacities. The location of the bottom column flexural hinge is set at an elevation of 0.3 times the first story column height in order to achieve both performance and economy goals. In this paper, the effectiveness of the proposed design method is verified by four two-story L-shape bidirectional SPSW finite element model (FEM) analyses. The pushover analyses on the FEMs confirm that the flexural demands and the plastic hinge locations of the bottom corner VBEs can be predicted by the proposed method. This research also investigates the effectiveness of the composite action of the concrete slab and steel beam in the SPSW’s top boundary element using FEM analysis. Analysis results show that the composite action is not pronounced since the vertical downward panel forces are applied on the beam bottom flange.
Title Optimization of Steel Panel Dampers for Moment Resisting Frame Designs
Author Chu-Hung Chang, Keh-Chyuan Tsai
Keywords steel panel damper, seismic design, capacity design, shear buckling, optimization design, moment resisting frame
Abstract The proposed 3-segment steel panel damper (SPD) consists of one middle inelastic core (IC) and two end elastic joint (EJ) wide-flange sections. During earthquakes, the two EJs of the same cross-sectional property, are designed to remain elastic while the IC could undergo large inelastic shear deformation thereby dissipating seismic energy. In order to sustain a large deformation and delay the shear buckling of the IC web, stiffeners must be properly devised. In this study, optimization algorithm is adopted to proportion the SPDs and the boundary beams, and achieve the minimum steel weight design. It is assumed that two identical SPDs, one above and one below, are attached to the boundary beam mid-span. The MATLAB optimization toolbox combined the simulated annealing algorithm with the gradient-descent method is adopted to find the minimum steel weight design. The objective function is the total weight of the SPD, the boundary beam and the panel zone. The design variables are the sectional properties of the SPD, the boundary beam and the doubler plate thickness. Constraints include the capacity design of the SPD, boundary beam and panel zone, the stiffeners of the IC web, compact section and lateral torsional buckling limit state design requirements. The ”basic design”  is the lightest sections meeting all the constraints. The lateral stiffness of the two SPDs- to-boundary beam subassembly can be enhanced by either increasing the stiffness of the SPDs or the boundary beam. As examples, the optimization designs of increasing 50% more stiffness of the subassemblies as the new constraint were conducted also. While complying with the aforementioned constraints, the steel weight is increased by about 9% to achieve a 50% more stiffened design. The stiffness of the subassemblies are found enhanced most effectively by increasing the beam depths and web thicknesses.
TitleDevelopment and Seismic Tests of Steel Self-Centering Sandwiched Buckling-Restrained Braces (SC-SBRBs)
AuthorChung-Che Chou, Wen-Jing Tsai, Ping-Ting Chung
KeywordsSelf-centering sandwiched buckling-restrained brace (SC-SBRB), Cyclic test, Residual deformation, Energy dissipation
AbstractEarthquake-resisting frame systems that are designed based on current seismic provisions provide life safety performance in a large earthquake, but may have significant structural damage or residual drift due to energy dissipation in designated structural members. The damage leads to difficult or expensive repairs after a large earthquake. Therefore, development of a structural system that has both energy dissipation and self-centering properties in earthquakes is needed to improve the seismic performances of buildings. This paper presents a viable solution that was validated by multiple cyclic tests of an innovative brace, called a dual-core self-centering sandwiched buckling-restrained brace (SC-SBRB). The proposed brace combines the self-centering property of a dual-core self-centering brace (DC-SCB) and the energy dissipation of a sandwiched buckling-restrained brace (SBRB) together. The dual-core SC-SBRB is essentially a DC-SCB that is positioned concentrically with a SBRB to create both the self-centering and energy dissipation properties in either tension or compression. A 7860 mm-long dual-core SCSBRB, which uses ASTM A572 Gr. 50 steel as bracing members and ASTM A416 Grade 270 steel tendons as tensioning elements, was cyclically tested six times to validate its kinematics and cyclic performance. The test program demonstrated that the proposed dual-core SC-SBRB provides stable hysteretic responses with appreciable energy dissipation, self-centering behavior and large deformation capacity before low-cycle fatigue failure of the SBRB core.
Title Development and Application of a Variable Stiffness Isolation System Considering Ground Motion Characteristic
Author Zheng-Jia Liu, Chia-En Hsiao, Tzu-Kang Lin, Lyan-Ywan Lu
Keywords Stiffness-variable, energy of velocity, isolation system, semi-active control, minimum energy weighting
Abstract In recent years, the research of isolation and mitigation system has become more and more important. In the traditional isolation and mitigation system, the control effect may be reduced because of unknown earthquake types. To have the best effect of response reduction, the systems have to be adaptive with the earthquake type. To achieve that, an upgraded algorithm, Feed-forward Predictive Earthquake Energy Analysis (FPEEA), is proposed by considering the energy of earthquake velocity to have the optimal response. The new algorithm quickly evaluates the velocity energy to have the optimal weighting of minimum energy weighting (MEW). With the optimal weighting of the potential energy and the kinetic energy, the PFEEA can reduce the structural responses efficiently. In order to demonstrate the performance of the proposed algorithm, a single-degree-of-freedom structure is used as a benchmark in both numerical simulation and experimental verification. With predicting the optimal weighting in advance, the type of earthquake can be defined before the main shock of earthquake comes. The results have shown that the dynamic response of the structure can be effectively alleviated. Comparing to the structural responses of the MEW method, the performance of the proposed algorithm is similar to MEW or even better. The shaking table test also demonstrates the feasibility of applying the proposed algorithm in practical application.
Title A Life Cycle Consideration Structural Design Method for Concrete-Filled Steel Tubes Structure
Author Jenn-Chuan Chern, Zu-Liang Wu
Keywords creep, autogenous shrinkage, drying creep, CFT, structural design
Abstract The concrete-filled steel tubular structure has become a common structural type for buildings, which is matched with the use of self-compacting concrete, which is helpful for increasing the bearing capacity and stiffness of the high-rise building and increasing the effective use of the building area. However, the existing specifications and designs adopt the composite design method, and the structural design and the creep & Shrinkage behavior of the in-filled concrete and the interaction between concrete and steel tube are not fully considered in the existing structural design. This study introduces the time-dependent deformation characteristics of concrete and the necessity of applying local developed prediction formulas and proposes a design analysis method for concrete-filled steel tubular structures considering life cycle, and proposes design procedures and case studies to ensure the life expectancy in life cycle. During the period, the structural safety and serviceability of the structure can be ensured.

第三十三卷第四期 (期別132) (107年)

作者:

第三十三卷第四期 (期別132) (107年)

標題強脊結構系統之耐震行為研究
作者郭銘桂、林瑞良、蔡克銓
關鍵字層間位移角、廣義建築模型、強脊系統、非線性反應歷時分析
摘要為解決結構受震層間位移角分佈不均之問題，本研究希望利用簡化分析模型對強脊系統（strongback system）進行大量的參數分析，提出有效的設計參數。本研究以廣義建築模型（generalized building model，GBM）及含強脊系統之廣義建築模型（generalized building model with strongback，GBMSB）作為簡化的數值模型，針對在台北二區，第二類地盤的三、六、九和二十層建築進行參數分析。採用SRSS 振態疊加法估算最大彈性層間位移角，並利用層間位移角的標準偏差作為均勻度指標，評估層間位移角分佈之均勻性，使層間位移角的標準偏差為最小之設計為最佳設計。分析結果顯示強脊系統為純剪力型式，且其層勁度呈線性遞減，並且於一樓加勁的勁度分配法效果最佳。為了驗證參數分析之有效性，採用SAC 研究計畫中的九層鋼構造抗彎矩構架，和國家地震工程研究中心台南實驗室的三層鋼筋混凝土構架試體作為驗證例。將原始結構模型（分別稱為SAC9 和T3）、含最佳強脊系統之結構模型（分別稱為SAC9-SB 和T3-SB）、及含非最佳強脊系統之結構模型，分別利用PISA3D 結構分析程式進行非線性反應歷時分析。結果顯示配置最佳強脊系統之SAC9-SB 和T3-SB 層間位移角之標準偏差平均值最小，能使層間位移角分佈最為均勻。
TitleStrongback systems for enhancing the seismic performance of buildings
AuthorMeng-Kwee Kek, Jui-Liang Lin, Keh-Chyuan Tsai
Keywordsinter-story drift ratio, generalized building model, strongback, nonlinear response history analysis
AbstractIn order to reduce the variations of peak inter-story drifts occurred in earthquakes along the building height, this research conducts the parametric study of the buildings with strongback systems through simplified numerical models. The generalized building model (GBM) and generalized building model with strongback (GBMSB) are employed as the simplified numerical models in the parametric study. This study investigated 3, 6, 9 and 20-story buildings.The peak inter-story drift ratios along the building height are computed by using the response spectrum analysis method, in which the peak modal responses are combined according to the SRSS method. The optimization objective is to minimize the standard deviation of the peak inter-story drift ratios. The optimal stiffness distribution of a strongback is thus obtained.The results of parametric study show that when a pure shear-type strongback, whose first story is stiffened and its story stiffness decreases linearly along the height, the standard deviation of inter-story drifts is minimized. The effectiveness of the proposed method is verified by investigating one 9-story steel building and one 3-story reinforced concrete (RC) building.The 9-story steel moment resisting frame, designated as SAC9, was a prototype building located in Los Angeles adopted in SAC steel research project. In addition, the 3-story RC building, designated as T3,was tested using shaking table at Tainan Laboratory of National Center for Research on Earthquake Engineering. The optimal designs of SAC9 and T3 with the strongbacks are designated as SAC9-SB and T3-SB, respectively. Nonlinear response history analyses (NRHA) of SAC9, T3, SAC9-SB, T3-SB models and the others with different properties of strongback systems were conducted using PISD3D program. The NRHA result shows that SAC9-SB and T3-SB have smaller standard deviations than those using other strongback properties. The analysis results confirm the effectiveness of the proposed method in proportioning the strongback for buildings.
標題鋼梁接箱型柱之內橫隔斷裂試驗與有限元素模型分析研究
作者吳忠哲、李昭賢、蔡青宜、林克強、莊勝智、蔡克銓
關鍵字鋼箱型柱、電熱熔渣焊、鋼材斷裂預測模型、鋼梁柱接頭、有限元素分析、圓周刻痕拉伸試驗、電熱熔渣焊儲倉口
摘要鋼箱型斷面柱構件具有雙強軸的特性，因此國內鋼建築結構中應用非常普遍。為傳遞梁端彎矩至柱構件，箱型柱內與梁翼同高處須配置與梁翼同厚的橫隔板。內橫隔板與柱板間焊接常使用電熱熔渣焊(Electro Slag Welding, ESW)工法，此種焊道施作便利且效率高，已大量使用於國內鋼結構製造廠。然而，ESW 施做時的高入熱量恐導致其焊道及其周圍母材結晶過大與抗衝擊性質較差，此現象亦常導致梁柱發生非預期的脆性破壞。為避免ESW 發生脆性破壞及量化ESW 破壞之機制，本研究採用既有的鋼材斷裂預測模型，利用有限元素模型對試體進行斷裂預測分析。本研究進行三組梁柱接頭試驗，藉由變化試驗之載重歷時與ESW 施工儲倉口截面形狀，探討試體破壞時機並驗證鋼材斷裂預測模型之可行性。實驗結果顯示證實累積塑性應變大小確實影響其破壞時機；ESW 儲倉口截面由矩形變為喇叭口形時，顯示若增加ESW 之熔透範圍可增加接頭試驗耐震性能。為應用斷裂預測模型，藉圓周刻痕拉伸(Circumferential Notched Tensile, CNT)試驗與有限元素模型分析，將所得之材料參數對ESW 元件試驗與梁柱接頭試驗進行斷裂預測分析。分析結果顯示，ESW 之幾何形狀及相對位置對於破壞時機影響甚大，因此顯示破壞預測分析與CNT 試驗之可行性，以及焊道超音波檢測(Ultrasonic Test, UT)之重要性。
TitleFracture Tests and Finite Element Analysis of Diaphragm Connection in Steel Beam-to-Box Column Joints
AuthorChung-Che Wu, Chao-Hsien Li, Ching-Yi Tsai, Ker-Chun Lin, Sheng-Jhih Jhuang, Keh-Chyuan Tsai
Keywordssteel box column, electro-slag welding, heat affected zone, fracture prediction model, steel beam-to-box column connection, finite element model analysis, circumferential notched tensile test, ultrasonic test
AbstractSteel box columns are widely used in steel building structures in Taiwan due to the strong axes in two directions. In order to transfer the beam end moment to column, diaphragm plates of the same thickness and elevations as beam flanges are usually welded inside box column. Electro-slag welding (ESW) process is typically used in attaching the diaphragms to column flanges. This ESW process has been widely used in steel beam-to-box column joints in Taiwan because of its’ convenience and efficiency. However, ESW may increase the hardness of the welds and heat affected zones (HAZs), while reduce the Charpy-V Notch (CVN) strength in HAZ. This situation could cause the diaphragm to column flange weld to suffer premature fracture before a large plastic rotation is developed in beam-to-box column joints. In order to quantify the critical eccentricity and the effectiveness of predicting the fractures, this study utilizes the fracture prediction model and finite element model (FEM) analysis to correlate the test results. In this study, three beam-to-box column connection subassembly tests have been conducted with a different loading protocol or the shape of ESW chamber. Test results show that the fracture instances can be predicted based on the cumulative plastic deformation in the HAZs. Tests confirm that the possible fracture of the diaphragm to column flange welds can be mitigated by enlarging the chamber of the ESW. When the fracture prediction model is applied, the material parameters were firstly established from the Circumferential Notched Tensile (CNT) tests and FEM analysis. Subsequently, these parameters were used to predict the fractures observed in the ESW component tests and beam-to-box column connection subassembly tests. The fracture locations and instances can be reasonably well predicted by a suitable FEM model analysis. Thus, the effectiveness of CNT and the fracture model are confirmed. Analytical results also show fracture instances and locations are sensitive to the relative locations of the ESW and the beam flange. Thus, the importance of ultrasonic test in assuring the quality of the ESW is evident.
標題考慮塗裝系統更新週期影響之鋼構橋梁生命週期成本評估方法建構
作者邱建國、陳正誠、陳敏祐
關鍵字鋼構橋梁、劣化速率、生命週期維護成本、防蝕塗裝系統
摘要鋼構橋梁於維護階段主要之費用分為定期維護成本及防蝕塗裝成本。對於定期維護成本而言，本研究主要使用貝氏更新決定構件/元件劣化速率，並且推估不同維護週期下之費用分布，以選擇成本最小之定期維護週期。防蝕塗裝成本除材料費用外須考慮施工費用，本研究主要參考歷史資料，以建立防蝕塗裝工程洐生之施工機具與相關費用推估模式。此外，為使設定之塗裝系統更換週期更貼近實務，本研究亦進行鋼構橋梁常用塗裝系統之耐用年限評估，除加速耐候試驗與現地曝曬試驗外，並參考文獻之塗膜消耗速率以建議不同性能要求下之對應耐用年限，以做為不同塗裝系統更新週期之設定依據。本研究以某直轄市之26 座鋼構橋梁為例，主要選取 8 項橋梁構件/元件，共包括：橋面板、支承、伸縮縫、面層、防落橋裝置、主結構、欄杆及護牆、排水設施等，利用上列元件/構件估算所得維護費用，再依係數進行修正以得出橋梁整體定期維護成本，並試算不同塗裝系統及更新週期下之費用，以了解其對生命週期維護成本之影響，可做為後續維護計畫之擬定參考。
TitleLife-cycle Cost Assessment Method Development for Steel Bridges Considering the Effect of the Renewal Periods of Coating Systems
AuthorC. K. Chiu, C. C. Chen, M. Y. Chen
Keywordssteel bridge, deterioration rate, life-cycle maintenance cost, anti-corrosion coating system
AbstractIn the maintenance stage of steel bridges, the costs can be divided into the regular maintenance cost and anti-corrosion coating cost. For the regular maintenance cost, this work adopts the Bayesian updating to determine the deterioration rate of each component or member. Additionally, based on the minimal regular maintenance cost, the corresponding maintenance period can be obtained. In order to quantify the renewal cost of the anti-corrosion coating system, this work conducts the accelerated-weathering test and site exposure test for the anti-corrosion coating materials. In addition to the testing results, the past investigations on the consuming rates of the specified coating materials for steel bridges are referred to determine the renewal periods of the anti-corrosion coating system. Finally, an assessment method of the life-cycle cost (LCC) of steel bridges is developed to investigate effect of the renewal period of the anti-corrosion coating system on the LCCs for 26 steel bridges located in a special municipality in Taiwan.
標題容量位移雙反應譜－基於損傷之鋼筋混凝土橋梁耐震設計與評估法
作者王柄雄、張國鎮、歐昱辰
關鍵字反應譜、非彈性位移比、損傷指標、平滑型遲滯模型、遠域地震、近斷層地震、耐震設計與評估、鋼筋混凝土橋梁
摘要本研究提出一套容量位移反應譜(Capacity-based inelastic displacement spectra)，其係由一個非彈性位移比CR反應譜與一個相應之損傷指標DI反應譜所構成之雙反應譜(Dual spectra)，可用於鋼筋混凝土橋梁之耐震性能設計與評估。反應譜之建置係藉由一個功能強大的平滑型遲滯模型，可考慮不同橋柱設計參數之影響，並分別就遠域及近斷層地震進行單自由度系統之非線性動力歷時分析而得。本研究證實在任何的位移加載歷程下，Park and Ang 所提出之損傷指標不但可用來準確地預測橋柱的強度衰減時機，更可作為評估橋柱真實可視破壞狀態的良好指標，進而得到較佳的橋梁耐震性能評估結果。採用遠域地震所計算之CR反應譜顯示，當結構週期約略大於0.8 秒時，非彈性位移比CR可近似滿足等位移原理；但就近斷層地震而言，在全部反應譜週期範圍內則皆不滿足此原理。此外，分析結果顯示近斷層地震會較遠域地震產生明顯較大的CR及DI值，且當相對強度比R = 5.0 時，大部分本研究所考量之設計方案皆無法承受所考慮之近斷層地震的侵襲。最後，根據所計算之反應譜分析結果，本研究分別就遠域及近斷層地震各提出一套非彈性位移比CR及相應之損傷指標DI之反應譜公式，並依據所建置之容量位移反應譜，提出一套基於損傷之鋼筋混凝土橋梁耐震性能設計與評估方法。
TitleCapacity-Based Inelastic Displacement Spectra for Seismic Design and Evaluation of Reinforced Concrete Bridges
AuthorPing-Hsiung Wang, Kuo-Chun Chang, Yu-Chen Ou
Keywordsspectrum, inelastic displacement ratio, damage index, smooth hysteretic model, far-field earthquake, near-fault earthquake, seismic design and evaluation, RC bridges
AbstractCapacity-based inelastic displacement spectra that comprised an inelastic displacement (CR) spectrum and a corresponding damage state (DI) spectrum was proposed in this study to aid seismic evaluation and design of reinforced concrete (RC) bridges. Nonlinear time history analyses of SDOF systems were conducted using a versatile smooth hysteretic model that accounted for the influences of various column design parameters when subjected to far-field and near-fault ground motions. It was proved that the Park and Ang’s damage index not only can be used to accurately predict the onset of strength deterioration, but also can be a good indicator for assessing the actual visible damage condition of column regardless of its loading history, providing a better insight into the seismic performance of bridges. The computed spectra show that the CR for far-field ground motions approximately conforms to the equal displacement rule for structural period (Tn) larger than around 0.8 seconds, but that for near-fault ground motions departs from the rule in the whole spectral regions. Moreover, the near-fault ground motions would lead to significantly greater CR and DI than far-field ground motions and most of the design scenarios investigated in this research cannot survive the near-fault ground motions when relative strength ratio R = 5.0. Based on the computed spectra, CR and DI formulae are presented as a function of Tn, R, and various design parameters for far-field and near-fault ground motions. Finally, application of the proposed spectra to the performance-based seismic design and evaluation of RC bridge was presented using DI as the performance objective.
標題以極值分析理論推估最佳設計風壓係數
作者羅元隆、Michael Kasperski
關鍵字設計風速、極值分布曲線、風壓係數、最佳設計非超越機率
摘要決定設計風載重大小取決於設計風速與設計風壓係數的評估。其中設計風速的評估由實場監測長年累積的數據經極值分析理論求得，因此首先必須對於標的物的氣象資料資訊進行了解。再者，設計風壓係數由標的物的幾何外型決定，可以經由正確的物理縮尺風洞試驗，在滿足各種無因次化參數條件下，獲得標的物每個局部位置的風壓係數值。設計風速與設計風壓係數的機率密度分布函數透過乘冪計算，必須滿足對於標的物破壞的目標超越機率。本研究以台灣本土的氣象資料進行設計風速的評估，輔以一簡單的高層建築物理縮尺實驗作為設計風壓係數的推算範例，推算出滿足於標的物分類及回歸期的最佳設計風壓係數值及其相對應之最佳設計非超越機率值、最佳設計風載重。
TitleEstimation of Design Pressure Coefficient Based on Extreme Value Analysis Theory
AuthorYuan-Lung Lo, Michael Kasperski
KeywordsDesign wind speed, Extreme value distribution, Pressure coefficient, Optimal design fractile
AbstractTo determine a proper design wind load relies on correct evaluations on design wind speed and design wind pressure coefficient. The evaluation on design wind speed requires the understanding of local meteorological information accumulated for a long-term period and the knowledge of extreme value analysis; wind pressure coefficient of the target structure can be obtained via properly arranged wind tunnel test fulfilling the satisfactory demand of all non-dimensional aerodynamic parameters. By satisfying the target exceedance probability of failure of a target building, convolution process of probability densities of design wind speed and pressure coefficients is carried out and then the optimal design pressure coefficient can be found through iterative calculation. This study intends to apply local meteorological information in Taiwan and a simple wind tunnel test to demonstrate the determination of the optimal design fractile and its corresponding design wind pressure coefficient and design wind load.

Vol.33/No.4 (132) (2018)

作者:

Vol.33/No.4 (132) (2018)

Title Strongback systems for enhancing the seismic performance of buildings
Author Meng-Kwee Kek, Jui-Liang Lin, Keh-Chyuan Tsai
Keywords inter-story drift ratio, generalized building model, strongback, nonlinear response history analysis
Abstract In order to reduce the variations of peak inter-story drifts occurred in earthquakes along the building height, this research conducts the parametric study of the buildings with strongback systems through simplified numerical models. The generalized building model (GBM) and generalized building model with strongback (GBMSB) are employed as the simplified numerical models in the parametric study. This study investigated 3, 6, 9 and 20-story buildings.The peak inter-story drift ratios along the building height are computed by using the response spectrum analysis method, in which the peak modal responses are combined according to the SRSS method. The optimization objective is to minimize the standard deviation of the peak inter-story drift ratios. The optimal stiffness distribution of a strongback is thus obtained.The results of parametric study show that when a pure shear-type strongback, whose first story is stiffened and its story stiffness decreases linearly along the height, the standard deviation of inter-story drifts is minimized. The effectiveness of the proposed method is verified by investigating one 9-story steel building and one 3-story reinforced concrete (RC) building.The 9-story steel moment resisting frame, designated as SAC9, was a prototype building located in Los Angeles adopted in SAC steel research project. In addition, the 3-story RC building, designated as T3,was tested using shaking table at Tainan Laboratory of National Center for Research on Earthquake Engineering. The optimal designs of SAC9 and T3 with the strongbacks are designated as SAC9-SB and T3-SB, respectively. Nonlinear response history analyses (NRHA) of SAC9, T3, SAC9-SB, T3-SB models and the others with different properties of strongback systems were conducted using PISD3D program. The NRHA result shows that SAC9-SB and T3-SB have smaller standard deviations than those using other strongback properties. The analysis results confirm the effectiveness of the proposed method in proportioning the strongback for buildings.
Title Fracture Tests and Finite Element Analysis of Diaphragm Connection in Steel Beam-to-Box Column Joints
Author Chung-Che Wu, Chao-Hsien Li, Ching-Yi Tsai, Ker-Chun Lin, Sheng-Jhih Jhuang, Keh-Chyuan Tsai
Keywords steel box column, electro-slag welding, heat affected zone, fracture prediction model, steel beam-to-box column connection, finite element model analysis, circumferential notched tensile test, ultrasonic test
Abstract Steel box columns are widely used in steel building structures in Taiwan due to the strong axes in two directions. In order to transfer the beam end moment to column, diaphragm plates of the same thickness and elevations as beam flanges are usually welded inside box column. Electro-slag welding (ESW) process is typically used in attaching the diaphragms to column flanges. This ESW process has been widely used in steel beam-to-box column joints in Taiwan because of its’ convenience and efficiency. However, ESW may increase the hardness of the welds and heat affected zones (HAZs), while reduce the Charpy-V Notch (CVN) strength in HAZ. This situation could cause the diaphragm to column flange weld to suffer premature fracture before a large plastic rotation is developed in beam-to-box column joints. In order to quantify the critical eccentricity and the effectiveness of predicting the fractures, this study utilizes the fracture prediction model and finite element model (FEM) analysis to correlate the test results. In this study, three beam-to-box column connection subassembly tests have been conducted with a different loading protocol or the shape of ESW chamber. Test results show that the fracture instances can be predicted based on the cumulative plastic deformation in the HAZs. Tests confirm that the possible fracture of the diaphragm to column flange welds can be mitigated by enlarging the chamber of the ESW. When the fracture prediction model is applied, the material parameters were firstly established from the Circumferential Notched Tensile (CNT) tests and FEM analysis. Subsequently, these parameters were used to predict the fractures observed in the ESW component tests and beam-to-box column connection subassembly tests. The fracture locations and instances can be reasonably well predicted by a suitable FEM model analysis. Thus, the effectiveness of CNT and the fracture model are confirmed. Analytical results also show fracture instances and locations are sensitive to the relative locations of the ESW and the beam flange. Thus, the importance of ultrasonic test in assuring the quality of the ESW is evident.
Title Life-cycle Cost Assessment Method Development for Steel Bridges Considering the Effect of the Renewal Periods of Coating Systems
Author C. K. Chiu, C. C. Chen, M. Y. Chen
Keywords steel bridge, deterioration rate, life-cycle maintenance cost, anti-corrosion coating system
Abstract In the maintenance stage of steel bridges, the costs can be divided into the regular maintenance cost and anti-corrosion coating cost. For the regular maintenance cost, this work adopts the Bayesian updating to determine the deterioration rate of each component or member. Additionally, based on the minimal regular maintenance cost, the corresponding maintenance period can be obtained. In order to quantify the renewal cost of the anti-corrosion coating system, this work conducts the accelerated-weathering test and site exposure test for the anti-corrosion coating materials. In addition to the testing results, the past investigations on the consuming rates of the specified coating materials for steel bridges are referred to determine the renewal periods of the anti-corrosion coating system. Finally, an assessment method of the life-cycle cost (LCC) of steel bridges is developed to investigate effect of the renewal period of the anti-corrosion coating system on the LCCs for 26 steel bridges located in a special municipality in Taiwan.
Title Capacity-Based Inelastic Displacement Spectra for Seismic Design and Evaluation of Reinforced Concrete Bridges
Author Ping-Hsiung Wang, Kuo-Chun Chang, Yu-Chen Ou
Keywords spectrum, inelastic displacement ratio, damage index, smooth hysteretic model, far-field earthquake, near-fault earthquake, seismic design and evaluation, RC bridges
Abstract Capacity-based inelastic displacement spectra that comprised an inelastic displacement (CR) spectrum and a corresponding damage state (DI) spectrum was proposed in this study to aid seismic evaluation and design of reinforced concrete (RC) bridges. Nonlinear time history analyses of SDOF systems were conducted using a versatile smooth hysteretic model that accounted for the influences of various column design parameters when subjected to far-field and near-fault ground motions. It was proved that the Park and Ang’s damage index not only can be used to accurately predict the onset of strength deterioration, but also can be a good indicator for assessing the actual visible damage condition of column regardless of its loading history, providing a better insight into the seismic performance of bridges. The computed spectra show that the CR for far-field ground motions approximately conforms to the equal displacement rule for structural period (Tn) larger than around 0.8 seconds, but that for near-fault ground motions departs from the rule in the whole spectral regions. Moreover, the near-fault ground motions would lead to significantly greater CR and DI than far-field ground motions and most of the design scenarios investigated in this research cannot survive the near-fault ground motions when relative strength ratio R = 5.0. Based on the computed spectra, CR and DI formulae are presented as a function of Tn, R, and various design parameters for far-field and near-fault ground motions. Finally, application of the proposed spectra to the performance-based seismic design and evaluation of RC bridge was presented using DI as the performance objective.
Title Estimation of Design Pressure Coefficient Based on Extreme Value Analysis Theory
Author Yuan-Lung Lo, Michael Kasperski
Keywords Design wind speed, Extreme value distribution, Pressure coefficient, Optimal design fractile
Abstract To determine a proper design wind load relies on correct evaluations on design wind speed and design wind pressure coefficient. The evaluation on design wind speed requires the understanding of local meteorological information accumulated for a long-term period and the knowledge of extreme value analysis; wind pressure coefficient of the target structure can be obtained via properly arranged wind tunnel test fulfilling the satisfactory demand of all non-dimensional aerodynamic parameters. By satisfying the target exceedance probability of failure of a target building, convolution process of probability densities of design wind speed and pressure coefficients is carried out and then the optimal design pressure coefficient can be found through iterative calculation. This study intends to apply local meteorological information in Taiwan and a simple wind tunnel test to demonstrate the determination of the optimal design fractile and its corresponding design wind pressure coefficient and design wind load.

第三十三卷第三期 (期別131) (107年)

作者:

第三十三卷第三期 (期別131) (107年)

標題鋼筋混凝土圓形柱橫向鋼筋圍束效果之探討
作者李台光、陳正誠
關鍵字鋼筋混凝土圓形柱、橫向鋼筋、圍束效果
摘要本研究完成8支大尺寸鋼筋混凝土圓形柱試體之反復側向載重試驗，共規劃R、S33、S17 及D33 等4 個系列，以箍筋、繫筋總圍束力維持固定為原則，箍筋之圍束力以箍筋2 倍的斷面積與標稱降伏強度之乘積計算，而對於十字型及井字型配置之繫筋，分別以1 根及2 根繫筋斷面積與標稱降伏強度之乘積，計算繫筋之圍束力，探討井字型及十字型等2 種繫筋於圍束柱混凝土的可行性及有效性。研究結果顯示：(1)含十字型及井字型組合繫筋之鋼筋混凝土圓形柱，其耐震性能與側力方向具有某種關聯性，但並不顯著。故圓柱繫筋施工時應不需要特別旋轉或是調整十字型及井字型組合繫筋之方向或指定方向。(2)以本研究圍束力之定義，在相同總圍束力下，圓箍筋的圍束效果優於十字型及井字型配置之組合繫筋，另十字型繫筋比井字型繫筋圍束效果稍佳，組合繫筋之圓箍筋等效圍束力折減之計算，與繫筋配置形式及圍束力比有關，尚需後續進一步研究釐清。
TitleThe confinement effectiveness of transverse reinforcement in circular reinforced concrete columns
AuthorTai-Kuang Lee, Cheng-Cheng Chen
KeywordsCircular RC Columns, Transverse Reinforcement, Confinement Effectiveness
AbstractIn this study, a lateral cyclic load test was conducted on eight specimens of large-sized circular reinforced concrete (RC) columns to investigate the confinement effectiveness of circular ties and lap-spliced crossties. Totally, there are four series of specimens including R, S33, S17 and D33 constructed and tested. In single-cross crossties, the confining force of transverse reinforcement is calculated by adding the confinement effectiveness of one crosstie cross-sectional area. On the other hand, in double-cross crossties, the confining force of transverse reinforcement is calculated by adding the confinement effectiveness of two crosstie cross-sectional areas. The research results are presented as follows: (a) The seismic performance of circular RC columns with single-cross and double-cross lap-spliced crosstie correlates with the lateral loading direction. But its influence is not significant (b) The confinement effectiveness of circular tie is better than that of single-cross and double-cross lap-spliced crosstie. The reduction influence of lap-spliced crossties depends upon crosstie layout and the confinement force ratio. More details need further studies.
標題以應力波法非破壞檢測混凝土植筋epoxy握裹長度
作者鄧凱均、莊江隆、林宜清、江國睿
關鍵字植筋品質、非破壞檢測、應力波動、敲擊回音法
摘要本文開發以波動技術非破壞檢測植筋握裹長度與植筋深度。首先以有限元素法對植筋結構之應力波動訊號進行數值模擬分析，以瞭解植筋之波動行為，並經由植筋試體之敲擊回音試驗來驗證數值分析結果。研究結果顯示，在頻譜圖中可以發現明顯尖峰位於主導頻率上，該主導頻率主要由植筋外露長度與植筋握裹長度所控制，對特定之植筋外露長度時，植筋握裹長度越長所得頻率就越高。本文以數值分析建立三種不同植筋外露長度(10、15 與20公分)，頻率與植筋握裹長度間之關係曲線。試驗檢測結果與數值模擬相當吻合。研究結果建議現場植筋握裹長度檢測程序如下：(1)以超音波測得植筋總長度，由測得之植筋總長度扣除外露長度即可求得植筋深度；(2)執行敲擊回音試驗測得主導頻率，代入所建立的迴歸方程式，即可以預估植筋握裹長度。試驗結果顯示預估之植筋握裹長度誤差大都在1 公分以內，證明本文所開發檢測法可以作為現地植筋施工品質之檢驗用。
TitleUse of Stress Wave methods for Nondestructive Inspection of Epoxy-Bonded Length of Post-installed Rebars in Concrete
AuthorKai-Chung Teng, Chiang-Lung Chuang, Yiching Lin, Guo-Ruei Jiang
Keywordsquality of planting bars, nondestructive evaluation, stress waves, impact-echo
AbstractThis article develops a stress wave-based technology to detect non-destructively the epoxy-bonded length and embedded depth of post-installed rebars in concrete. Firstly, the finite element method (FEM) was used to simulate the stress wave propagation signal of the post-installed rebars in concrete to understand the wave propagation behavior of anchorage rebar. The results of the numerical analysis were verified by the impact-echo test performed on the concrete specimens containing post-installed rebars. The results show that a high amplitude peak can be found at the dominant frequency in the spectrum. The dominant frequency is mainly controlled by the exposed length and the epoxy-bonded length of the post-installed rebar. For a specific exposed length of the planting rebar, the longer the epoxy-bonded length, the higher the dominant frequency. In this paper, numerical analysis of three different exposed lengths (10,15 and 20 cm) were considered to establish the relationship between the dominant frequency and the epoxy-bonded length. The experimental results are in good agreement with those obtained from the numerical simulation. The results obtained from this study suggested that the epoxy-bonded length of post-installed rebar can be evaluated as follows: (1) The total length of the post-installed rebar can be measured by ultrasound. The embedded depth of the post-installed rebar is obtained by deducting the exposed length from the measured total length; (2) Impact-echo test measured the dominant frequency. The epoxy-bonded length can be predicted by substituting the dominant frequency into the established regression equation. The test results show that the estimated error of embedding length of post-installed rebar is mostly within 1 cm, which proves that the test method developed in this paper can be used to evaluate the quality of planting bars.
標題台灣混凝土變形預測模式B4-TW 建置(ㄧ)：基本潛變、乾燥潛變與總潛變
作者劉庭愷、陳振川
關鍵字混凝土、長期變形、潛變、收縮、資料庫
摘要台灣目前之混凝土工程設計規範缺乏混凝土潛變之預測公式，工程師設計大多依循美國ACI 規範，參考美國AASHTO 公路橋梁設計規範；歐洲CEB-FIP、RILEM；或日本JSCE、JCI 等作法。基於台灣混凝土材料、配比、施工與環境之地區特性，台灣著實需要發展良好之本土化混凝土潛變預測公式。本文指出運用現有之國內外混凝土潛變模式預測台灣混凝土資料之情形，結果顯示大多現有模式皆呈現低估的現象。本研究評估並選用Bažant 2015年提出之Model B4 潛變預測公式為基礎，針對上述之台灣混凝土特性進行本土化修正，分別是在瞬時應變項中考慮因粒料堅實度較為不足造成之混凝土彈性模數折減；在基本潛變項中考慮因高漿體量及粒料性質造成高變形之現象；在乾燥潛變項中考慮台灣常用之砂岩粒料造成之影響。結果顯示，進行本土化修正後之Model B4-TW 潛變預測公式與原始Model B4相比，預測台灣混凝土基本潛變資料時，迴歸分析中之決定係數 R2由 0.52提升至0.78；預測總潛變資料變形時R2由 0.76 提升至 0.81。除 R2外，各國學者提出之不同統計指標也顯示Model B4-TW 預測台灣潛變資料之表現較佳，建議發展成為適用台灣本土之混凝土潛變預測公式。
TitleEstablishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( I ) :Basic Creep, Drying Creep and Total Creep
AuthorTing-Kai Liu, Jenn-Chuan Chern
KeywordsConcrete, Long-term Deformation, Creep, Shrinkage, Database
AbstractAt present the concrete design code in Taiwan lacks any predictive model for concrete creep, which is why most engineers in Taiwan follow the models of the American Concrete Institute (ACI) or the American Association of State Highway and Transportation Officials (AASHTO) of the US; the European CEB-FIP and RILEM ; or the methods of the JSCE or JCI of Japan. Although the physical and chemical characteristics of concrete are essentially the same all across the world, each location uses its own constituent materials and mix design. In the present study, looking at the establishment of a concrete creep database for concrete in Taiwan, we have seen that the aggregate used in concrete of Taiwan is of lower quality. When formulating a mix design to attain higher strength, the resulting concrete will tend to have a high paste content, high cement content, low water cement ratio, and low aggregate/cement ratio. These local characteristics of concrete in Taiwan may lead to inaccuracies when they are applied to foreign predictive formulas, and in turn influence the structural behavior and safety of the concrete structures. Taiwan therefore has a manifest need for developing better localized predictive models for concrete creep. This study first presents the results from the predictive models for concrete creep (foreign and domestic formulas) applied to concrete in Taiwan. At present, it may be seen that the norms tend to undervalue. Then, it evaluates and actually uses the Model B4 predictive model for concrete creep suggested by Bažant in 2015 as a basis for the correction of characteristics in localized concrete in Taiwan in multiple situations: in instantaneous deformation items the reduction of the elasticity modulus in concrete due to low-quality aggregate was considered; in basic creep items the phenomenon of high levels of deformation due to high paste content and aggregate property were considered; in drying creep items the effect of sandstone aggregate, which is often used in Taiwan, was considered. Our results were as follows: after using the Model B4-TW model, which has been corrected for localized concrete in Taiwan, we may compare the two models (Model B4 and Model B4-TW); when predicting basic creep for Taiwan concrete, the coefficient of determination R2 rose from 0.52 to 0.78; when predicting the total strain, R2 rose from 0.76 to 0.81. In addition to R2, the statistical indicators given by scholars from around the world have shown that the predictive capabilities of the Model B4-TW model for concrete creep data in Taiwan are superior to other models; thus it can be further developed as a predictive model for concrete creep in Taiwan.
標題台灣混凝土變形預測模式B4-TW 建置(二)：乾縮、自體收縮與總收縮
作者秦維邑、陳振川
關鍵字混凝土、長期變形、收縮、高爐石粉、飛灰、資料庫
摘要目前台灣之混凝土工程設計規範之混凝土收縮計算並未有明確公式，未能和混凝土材料之性質連結。致其計算常使用國外之美國 ACI、AASHTO，歐洲 CEB-FIP、RILEM 等預測公式。混凝土變形問題仍因牽涉世界各地區氣候環境、組成材料、配比及施工實務等，而有所差異性。台灣混凝土使用之粒料性質堅實度較為不足，配比設計時為追求強度達標，有使用高漿體量、高水泥量、低水灰比、低粒料量⁄水泥量比等特性，上述之本土化特性非使用國外預測公式可掌握，故台灣著實需要發展良好之本土化混凝土收縮預測公式。經評估現有國內外混凝土收縮預測規範，本文選用美國西北大學Bažant等人發展於2015 年提出之Model B4 收縮預測公式為基礎。針對上述之台灣混凝土特性進行本土化的修正，並考慮台灣常用之砂岩粒料造成之影響，找出適用於台灣之粒料修正參數。本文亦針對含有礦物摻料之混凝土進行摻料 影響之修正，選用FIB2000 作為自體收縮時間成長曲線，並修正Model B4 之礦物摻料參數表格，建立適合台灣使用之內含自體收縮項目的Model B4-TW 收縮預測公式。結果顯示，進行本土化修正後之Model B4-TW 收縮預測公式，在預測台灣普通混凝土或含有礦物摻料混凝土收縮時，均有極優表現，可發展為適用台灣本土之混凝土收縮預測公式。
TitleEstablishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( II ) : Drying Shrinkage, Autogenous Shrinkage and Total Shrinkage
AuthorWei-Yi Chin, Jenn-Chuan Chern
Keywordsconcrete, long-term deformation, shrinkage, blast-furnace slag cement, fly ash, dataset
AbstractAt present, there is no definite formula for concrete shrinkage calculation in the concrete engineering design code of Taiwan, which cannot link with the nature of local concrete material. Most engineers in Taiwan often use the formula of American Concrete Institution (ACI), the American Association of State Highway and Transportation Officials (AASHTO), and European CEB-FIP and RILEM codes. The problem of concrete deformation is still different because it involves the climate environment, mix design, proportion and construction practice in different areas. The aggregate quality of the concrete used in Taiwan is poor, and the mix is designed to achieve the strength with the use of high paste volume, high cement content, low water/cement ratio, low aggregate/cement ratio and other characteristics. The localization characteristics described above cannot be mastered by foreign prediction formula, so Taiwan really needs to develop a good local concrete shrinkage prediction formula. Based on the evaluation of the existing domestic and foreign concrete shrinkage prediction formulae, this paper chooses the model B4 shrinkage prediction formula developed in 2015 by Bažant of Northwestern University. With regard to the local characteristics of the concrete in Taiwan, and the effect of the commonly used sandstone aggregate in Taiwan, the modified parameters of the aggregate are found. In this paper, the influence of concrete containing mineral admixture is modified: the FIB2000 is selected as autogenous shrinkage time growth curve; and the mineral admixture parameter table of model B4 is modified. These local modifications led to the establishment of the Model B4-TW. The results show that the model B4-TW shrinkage prediction formula, which included autogenous shrinkage, after localization correction has excellent performance in predicting the shrinkage of normal concrete or concrete containing mineral admixture in Taiwan, and can be developed as a concrete shrinkage prediction formula for Taiwan.
標題鋼筋混凝土構架填充低台度磚牆之試驗研究
作者張順益、吳秉祈、巫垂晃
關鍵字鋼筋混凝土、低台度磚牆、反覆載重試驗、側推分析，剪力強度
摘要國內老舊校舍建築物在受到地震侵襲時，常因鋼筋混凝土構架內填充台度磚牆而發生短柱破壞。其中台度磚牆所提供的側向剪力強度，即是評估是否發生短柱破壞的重要因子，而台度磚牆的側向抗剪強度可能因其高寬比以及臨界破壞角的不同而有所差異。由於現行估算方法並未考慮台度磚牆高寬比的影響，因此並無法真實反應台度磚牆的側向剪力強度。本文特別針對低台度磚牆的側向抗剪強度進行三座試體的試驗研究，其中一座為空構架試體以及兩座填充不同高度之低台度磚牆構架試體，用來做為推估鋼筋混凝土構架內低台度磚牆側向剪力強度的重要依據。此三座試體除了進行反覆載重試驗之外，也利用側推模擬分析探討其耐震行為，將分析結果與試驗結果進行比較以推估低台度磚牆的側向剪力強度。從試驗結果可以得知低台度磚牆的高寬比為其側向剪力強度的重要因子之一，因此在推估低台度磚牆的側向剪力強度時，若能將高寬比這項因子適度的反應在計算的公式中，將可以更真實的預測台度磚牆的側向剪力強度。本研究已據此原則研擬出鋼筋混凝土構架填充低台度磚牆的剪力強度計算公式。
TitleExperimental Study of Reinforced Concrete Frame Filled with Low Masonry Window Spandrel
AuthorShuenn-Yih Chang, Ping-Chi Wu, Tsui-Huang Wu
KeywordsReinforced Concrete Building, Low Masonry Window Spandrel, Seismic Evaluation, Pushover Analysis
AbstractIn Taiwan area, structural damages caused by short column effect are very common in school buildings. The short column failure is closely related to the shear strength of the masonry window spandrel infilled within a reinforced concrete frame. The shear strength of a masonry window spandrel might be highly affected by its height-width ratio. However, this factor is not considered in the current evaluating formula and thus this formula seems unable to faithfully predict the shear strength. In fact, a formula for estimating the shear strength of a masonry window spandrel has been proposed. Because the height-width ratio of the masonry window spandrel was not considered in the formula its application is limited or might be inappropriate. To improve thisformula, three reinforced concrete frames were designed and fabricated for the cyclic loading tests for predicting the shear strength of a low masonry window spandrel within a reinforced concrete frame. One is a pure frame and the other two frames were infilled with different height of the masonry window spandrels. After conducting the cyclic loading tests of the three frames, the pushover analysis of each frame was also performed. Hence, after comparing the analytical result with the experimental results, the shear strength of the masonry window spandrel can be estimated. In this work, the height-weight ratio is chosen as an important factor for the newly proposed formula to estimate the shear strength of a low masonry window spandrel within a reinforced concrete frame. As a result, an improved formula for predicting the shear strength of the low masonry window spandrel within a reinforced concrete frame is proposed in this work.

Vol.33/No.3 (131) (2018)

作者:

Vol.33/No.3 (131) (2018)

TitleThe confinement effectiveness of transverse reinforcement in circular reinforced concrete columns
AuthorTai-Kuang Lee, Cheng-Cheng Chen
KeywordsCircular RC Columns, Transverse Reinforcement, Confinement Effectiveness
AbstractIn this study, a lateral cyclic load test was conducted on eight specimens of large-sized circular reinforced concrete (RC) columns to investigate the confinement effectiveness of circular ties and lap-spliced crossties. Totally, there are four series of specimens including R, S33, S17 and D33 constructed and tested. In single-cross crossties, the confining force of transverse reinforcement is calculated by adding the confinement effectiveness of one crosstie cross-sectional area. On the other hand, in double-cross crossties, the confining force of transverse reinforcement is calculated by adding the confinement effectiveness of two crosstie cross-sectional areas. The research results are presented as follows: (a) The seismic performance of circular RC columns with single-cross and double-cross lap-spliced crosstie correlates with the lateral loading direction. But its influence is not significant (b) The confinement effectiveness of circular tie is better than that of single-cross and double-cross lap-spliced crosstie. The reduction influence of lap-spliced crossties depends upon crosstie layout and the confinement force ratio. More details need further studies.
TitleUse of Stress Wave methods for Nondestructive Inspection of Epoxy-Bonded Length of Post-installed Rebars in Concrete
AuthorKai-Chung Teng, Chiang-Lung Chuang, Yiching Lin, Guo-Ruei Jiang
Keywordsquality of planting bars, nondestructive evaluation, stress waves, impact-echo
AbstractThis article develops a stress wave-based technology to detect non-destructively the epoxy-bonded length and embedded depth of post-installed rebars in concrete. Firstly, the finite element method (FEM) was used to simulate the stress wave propagation signal of the post-installed rebars in concrete to understand the wave propagation behavior of anchorage rebar. The results of the numerical analysis were verified by the impact-echo test performed on the concrete specimens containing post-installed rebars. The results show that a high amplitude peak can be found at the dominant frequency in the spectrum. The dominant frequency is mainly controlled by the exposed length and the epoxy-bonded length of the post-installed rebar. For a specific exposed length of the planting rebar, the longer the epoxy-bonded length, the higher the dominant frequency. In this paper, numerical analysis of three different exposed lengths (10,15 and 20 cm) were considered to establish the relationship between the dominant frequency and the epoxy-bonded length. The experimental results are in good agreement with those obtained from the numerical simulation. The results obtained from this study suggested that the epoxy-bonded length of post-installed rebar can be evaluated as follows: (1) The total length of the post-installed rebar can be measured by ultrasound. The embedded depth of the post-installed rebar is obtained by deducting the exposed length from the measured total length; (2) Impact-echo test measured the dominant frequency. The epoxy-bonded length can be predicted by substituting the dominant frequency into the established regression equation. The test results show that the estimated error of embedding length of post-installed rebar is mostly within 1 cm, which proves that the test method developed in this paper can be used to evaluate the quality of planting bars.
TitleEstablishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( I ) :Basic Creep, Drying Creep and Total Creep
AuthorTing-Kai Liu, Jenn-Chuan Chern
KeywordsConcrete, Long-term Deformation, Creep, Shrinkage, Database
AbstractAt present the concrete design code in Taiwan lacks any predictive model for concrete creep, which is why most engineers in Taiwan follow the models of the American Concrete Institute (ACI) or the American Association of State Highway and Transportation Officials (AASHTO) of the US; the European CEB-FIP and RILEM ; or the methods of the JSCE or JCI of Japan. Although the physical and chemical characteristics of concrete are essentially the same all across the world, each location uses its own constituent materials and mix design. In the present study, looking at the establishment of a concrete creep database for concrete in Taiwan, we have seen that the aggregate used in concrete of Taiwan is of lower quality. When formulating a mix design to attain higher strength, the resulting concrete will tend to have a high paste content, high cement content, low water cement ratio, and low aggregate/cement ratio. These local characteristics of concrete in Taiwan may lead to inaccuracies when they are applied to foreign predictive formulas, and in turn influence the structural behavior and safety of the concrete structures. Taiwan therefore has a manifest need for developing better localized predictive models for concrete creep. This study first presents the results from the predictive models for concrete creep (foreign and domestic formulas) applied to concrete in Taiwan. At present, it may be seen that the norms tend to undervalue. Then, it evaluates and actually uses the Model B4 predictive model for concrete creep suggested by Bažant in 2015 as a basis for the correction of characteristics in localized concrete in Taiwan in multiple situations: in instantaneous deformation items the reduction of the elasticity modulus in concrete due to low-quality aggregate was considered; in basic creep items the phenomenon of high levels of deformation due to high paste content and aggregate property were considered; in drying creep items the effect of sandstone aggregate, which is often used in Taiwan, was considered. Our results were as follows: after using the Model B4-TW model, which has been corrected for localized concrete in Taiwan, we may compare the two models (Model B4 and Model B4-TW); when predicting basic creep for Taiwan concrete, the coefficient of determination R2 rose from 0.52 to 0.78; when predicting the total strain, R2 rose from 0.76 to 0.81. In addition to R2, the statistical indicators given by scholars from around the world have shown that the predictive capabilities of the Model B4-TW model for concrete creep data in Taiwan are superior to other models; thus it can be further developed as a predictive model for concrete creep in Taiwan.
TitleEstablishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( II ) : Drying Shrinkage, Autogenous Shrinkage and Total Shrinkage
AuthorWei-Yi Chin, Jenn-Chuan Chern
Keywordsconcrete, long-term deformation, shrinkage, blast-furnace slag cement, fly ash, dataset
AbstractAt present, there is no definite formula for concrete shrinkage calculation in the concrete engineering design code of Taiwan, which cannot link with the nature of local concrete material. Most engineers in Taiwan often use the formula of American Concrete Institution (ACI), the American Association of State Highway and Transportation Officials (AASHTO), and European CEB-FIP and RILEM codes. The problem of concrete deformation is still different because it involves the climate environment, mix design, proportion and construction practice in different areas. The aggregate quality of the concrete used in Taiwan is poor, and the mix is designed to achieve the strength with the use of high paste volume, high cement content, low water/cement ratio, low aggregate/cement ratio and other characteristics. The localization characteristics described above cannot be mastered by foreign prediction formula, so Taiwan really needs to develop a good local concrete shrinkage prediction formula. Based on the evaluation of the existing domestic and foreign concrete shrinkage prediction formulae, this paper chooses the model B4 shrinkage prediction formula developed in 2015 by Bažant of Northwestern University. With regard to the local characteristics of the concrete in Taiwan, and the effect of the commonly used sandstone aggregate in Taiwan, the modified parameters of the aggregate are found. In this paper, the influence of concrete containing mineral admixture is modified: the FIB2000 is selected as autogenous shrinkage time growth curve; and the mineral admixture parameter table of model B4 is modified. These local modifications led to the establishment of the Model B4-TW. The results show that the model B4-TW shrinkage prediction formula, which included autogenous shrinkage, after localization correction has excellent performance in predicting the shrinkage of normal concrete or concrete containing mineral admixture in Taiwan, and can be developed as a concrete shrinkage prediction formula for Taiwan.
TitleExperimental Study of Reinforced Concrete Frame Filled with Low Masonry Window Spandrel
AuthorShuenn-Yih Chang, Ping-Chi Wu, Tsui-Huang Wu
KeywordsReinforced Concrete Building, Low Masonry Window Spandrel, Seismic Evaluation, Pushover Analysis
AbstractIn Taiwan area, structural damages caused by short column effect are very common in school buildings. The short column failure is closely related to the shear strength of the masonry window spandrel infilled within a reinforced concrete frame. The shear strength of a masonry window spandrel might be highly affected by its height-width ratio. However, this factor is not considered in the current evaluating formula and thus this formula seems unable to faithfully predict the shear strength. In fact, a formula for estimating the shear strength of a masonry window spandrel has been proposed. Because the height-width ratio of the masonry window spandrel was not considered in the formula its application is limited or might be inappropriate. To improve thisformula, three reinforced concrete frames were designed and fabricated for the cyclic loading tests for predicting the shear strength of a low masonry window spandrel within a reinforced concrete frame. One is a pure frame and the other two frames were infilled with different height of the masonry window spandrels. After conducting the cyclic loading tests of the three frames, the pushover analysis of each frame was also performed. Hence, after comparing the analytical result with the experimental results, the shear strength of the masonry window spandrel can be estimated. In this work, the height-weight ratio is chosen as an important factor for the newly proposed formula to estimate the shear strength of a low masonry window spandrel within a reinforced concrete frame. As a result, an improved formula for predicting the shear strength of the low masonry window spandrel within a reinforced concrete frame is proposed in this work.

第三十三卷第二期 (期別130) (107年)

作者:

第三十三卷第二期 (期別130) (107年)

標題中空鋼骨鋼筋混凝土構材之抗扭耐震效能提昇研究
作者許協隆、洪明德
關鍵字鋼骨鋼筋混凝土、撓曲扭轉行為、斜拉鋼筋
摘要本研究針對中空鋼骨鋼筋混凝土構材於偏心反覆載重下之撓曲扭轉性能進行探討，並以斜拉鋼筋改善構材之相關承載效能，研究中藉由配置不同斜拉鋼筋試體承受扭矩以及不同組合反覆載重之試驗，探討此補強設計對構材極限強度、破壞模式、能量消散行為之影響。研究結果顯示，含斜拉鋼筋之構材在偏心載重作用下，其勁度高於未加斜拉鋼筋之構材，適當配置斜拉鋼筋之構材除強度、韌性以及能量消散能力均較未配置者為佳，構材之扭轉撓曲效能亦可有效提昇，上述結果顯示，應用斜拉鋼筋於中空鋼骨鋼筋混凝土構材設計，具有相當之可行性。
TitleImproving Seismic Performance of Hollow Steel Reinforced Concrete Members with Inclined Bars
AuthorHsieh-Lung Hsu, Ming-Te Hong
Keywordssteel reinforced concrete, flexural-torsional behavior, inclined bars
AbstractThis study focused on the improvement of flexural-torsional behavior of hollow composite members subjected to eccentric cyclic loads. A series of composite members composed of encased steel tubes and reinforced concrete with various inclined bars were fabricated for testing. Member performance was evaluated by the strength, stiffness and energy dissipation during the loading history. Test results showed that the strength of members with inclined bars was significantly increased when subjected to torsion and combined loading coupled with torsion. Enhancement in energy dissipation further validated the applicability of incline bars to the performance improvement of hollow composite members.
標題橫向鋼筋配置方式對包覆填充型箱型柱混凝土圍束效果之影響
作者陳正誠、吳品達、周佳希
關鍵字包覆填充型箱型柱、鋼骨鋼筋混凝土、包覆型SRC 柱、填充型箱型柱
摘要包覆填充型箱型柱的橫向鋼筋，除了外圍之圍束箍筋外通常也需要配置繫筋以滿足規範之要求。但是繫筋受到鋼骨箱型柱的阻撓而無法直通，因此箱型柱板外圍混凝土的圍束往往無法滿足規範的要求。使用「角隅繫筋」、「接力式繫筋」及「側繫筋」為可能解決這個問題的方法。本文以10支大尺寸包覆填充型箱型短柱之軸向載重試驗，探討上述3 種繫筋對於圍束箱型柱外側混凝土的效果。由試驗結果獲得結論如下：（1）角隅繫筋無法提供主筋及角隅混凝土足夠之橫向支承，不能取代一般繫筋，也不能計入橫向鋼筋量。（2）接力式繫筋的作法可以達到圍束箱型柱板外側混凝土的效果，可行性相當高，應該可以計入橫向鋼筋量。（3）側繫筋的構想也相當程度達到圍束箱型柱板外側混凝土的效果，惟側繫筋是否可以直接計入橫向鋼筋量，還需要進一步的研究探討之。
TitleThe Effect of Different Transverse Reinforcement Schemes on the Confinement of Encased Concrete-Filled Box Columns
AuthorCheng-Cheng Chen, Pin-Da Wu, Jia-Xi Zhou
KeywordsEncased Concrete-Filled Steel Box Columns, steel reinforced concrete column, SRC column, encased box column, concrete filled box column.
AbstractThe concrete in a concrete-filled steel box column is confined by the box column. However, the confinement of the concrete outside the box column(referred as outer concrete hereafter) in an encased concrete-filled box column need to be provided by the steel cage which is composed of main reinforcement and transverse reinforcement. Due to the existence of the steel box column, the traditional ties used in RC columns can note be implemented here. In this article, the confinement effect of so called corner tie, combined tie and lateral tie are investigated experimentally. Ten large-sized concrete-encased concrete-filled steel box short columns were tested under monotonic axial compression. Based on the test results obtained, the following conclusions are made: (a) the corner tie was unable to provide sufficient lateral support to the longitudinal bar and corner concrete that required by the design code; (b) the use of combined tie can provide sufficient confinement to the outer concrete, (c) the potential of lateral tie in providing sufficient confinement to the outer concrete is high, however, further research is needed to confirm it.
標題具短衝程阻尼器之調諧質量阻尼器研究
作者賴勇安、孟繁嫣、連冠華、鍾立來
關鍵字調諧質量阻尼器、短衝程阻尼器、最佳化設計、阻尼器衝程
摘要現有調諧質量阻尼器之機構模型，裝設之阻尼器與質量塊的衝程相同，因此為配合質量塊衝程，常需選用較長衝程之阻尼器。長衝程之阻尼器，在製造上須預留相當伸縮之空間予阻尼器，因此阻尼器本身相當龐大，裝設不易，且長衝程阻尼器磨耗較高，於製造上需要較高的精度與油封技術，使其造價及維護費用較高。有鑒於此，本研究針對單純降低調諧質量阻尼器之阻尼器衝程， 提出「具短衝程阻尼器之調諧質量阻尼器(Short-Stroke Damper assembled in Tuned Mass Damper, SSD-TMD)」，並介紹其可行之機構。SSD-TMD 的機構特徵為，將傳統調諧質量阻尼器之彈簧元件分成兩段，使阻尼元件與第一段之彈簧元件並聯後，再與第二段彈簧元件串聯相接質量塊。由於阻尼器衝程與質量塊衝程並不相同，能經由適當設計大幅降低阻尼器之衝程，以避免使用長衝程之阻尼器，且不降低其減振效果。為使短衝程阻尼器消散與長衝程阻尼器等量之能量，因此短衝程阻尼器選用之阻尼係數較高，以提供較大之阻尼力。本文提出之SSD-TMD可行機構之詳細解說，並以傳統調諧質量阻尼器之最佳化設計參數為輔，提出SSD-TMD 之最佳化設計公式及設計流程，供工程師初步設計時參考。由台北101 結構案例分析結果顯示，不論頻率反應函數或是風力歷時模擬，SSD-TMD 皆能有效大幅降低阻尼器衝程，因而使用短衝程阻尼器即可；且如適當選取SSD-TMD 二段彈簧元件之勁度比值，其減振效果及質量塊衝程都可略優於傳統調諧質量阻尼器。
TitleStudy on Short-Stroke Damper Assembled in Tuned Mass Damper
AuthorYong-An Lai, Fan-Yen Meng, Kuan-Hua Lien, Lap-Loi Chung
Keywordstuned mass damper, short-stroke damper, optimal design, damper stroke
AbstractIn the conventional tuned mass damper (TMD), the damper stroke and the mass stroke must be the same, thus the long-stroke dampers are required for implementation in TMD. In addition, a considerable size and higher precision for manufacture of long-stroke damper majorly cause expensive budget for installation and maintenance of the TMD. According to the above features, the“Short-Stroke Damper assembled in Tuned Mass Damper (SSD-TMD)” is proposed in order to reduce the damper stroke in the TMD. In the SSD-TMD, the stiffness of SSD-TMD is separated into two parts. The first part is connected with the viscous damper in parallel. Then, the paralleled system is connected with the stiffness of the second part in series. Afterwards, the mass block is further attached to form the SSD-TMD. This assemblage will produce different strokes between the damper and the mass so that the damper stroke can be significantly mitigated under appropriate design of the stiffnesses and damping coefficient. In this article, the model of the SSD-TMD is firstly proposed. The design formulae and procedure of the SSD-TMD is also proposed by following the optimal design parameters for conventional TMD. The case study of the Taipei 101 structure implemented with the SSD-TMD shows that the damper stroke of the SSD-TMD can be dramatically reduced, so that the short-stroke dampers can be used to replace the long-stroke dampers. Furthermore, with suitable design of the SSD-TMD, both effectiveness of structural vibration reduction and mass stroke of the SSD-TMD can outperform the conventional TMD.
標題老舊建物耐震能力之簡易詳細評估
作者賴昱志、賴濤、鍾立來、黃國倫、楊耀昇、曾建創、林聖學、張筑媛
關鍵字耐震評估、極限基底剪力、現地試驗
摘要近年來台灣所發生的地震如921 大地震，均凸顯老舊建築物耐震能力不足之問題，因而導致人員傷亡，因此提升老舊建物之耐震能力極為重要，其中校舍可能需於震後供避難使用，應優先提升其耐震能力，國家地震中心因而針對發展出一套完整之耐震評估程序，以3 個階段進行篩選，包含簡易調查、初步評估法及詳細評估法，將耐震能力最不足之老舊校舍優先進行補強，以減少成本並提升效率。然國內除校舍外，亦有諸多其它老舊建築物(如：街屋、醫院、行政機關)之耐震能力亦亟需提升，故本研究提出使用極限彎矩平衡法，分別計算所有柱線之極限側向強度，依據其破壞模式，乘上折減係數，最後再進行疊加，可得建築物之極限基底剪力；並依據各柱線不同破壞模式，給予其相對之韌性容量，再依各柱線貢獻之側向強度採加權方式，得知該建物之韌性容量，最後採結構物耐震容量與需求比的方式，於側推分析前初步得知建築物之耐震能力；由於極限彎矩平衡法同時考量弱柱強梁及強柱弱梁之柱線情形，故可用於既有建築物之簡易詳細評估及完成補強設計建築物之簡易詳細評估。本研究初步以桃園縣瑞埔國小標準構架為例，進行簡易詳細評估，驗證其極限基底剪力及耐震容量均較現地試驗保守，故可針對老舊建物進行簡易之耐震評估及補強後之耐震評估，未來可使用此方法建立校舍外之其它老舊建物之初步評估方法，便於工程師使用。
TitleSimplified Seismic Evaluation Method on Old Buildings
AuthorYu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Yao-Sheng Yang, Chien-Chuang Tseng, Sheng-Hsueh Lin, Chu-Yuan Chang
Keywordsseismic evaluation, maximum base shear, in-situ test
AbstractThe earthquakes happen in Taiwan, such as Chi-Chi earthquake, let us know seismic capacity of old buildings is not enough. Because it may cause casualty, it is important to raise seismic ability of those old buildings. School buildings belong to public facility and provide people shelters when their home are damaged seriously by earthquake. Therefore their seismic ability should be raised as soon as possible. National Center for Research on Earthquake Engineering (NCREE) proposed complete procedures for seismic evaluation. The procedures of seismic evaluations include: simple survey, preliminary evaluation and detailed evaluation. After screening out school buildings which have less seismic capacity than seismic demand, we need to do seismic retrofit for them. However, there are lots of other old buildings in Taiwan (such as street houses, hospitals and executive agency) need to raise their seismic ability. In this paper, the method use Ultimate Moment Balanced Method to do Simplified Detailed Seismic Evaluation is proposed. The method first evaluates the lateral strength of each column line and multiplied by reduction factor which decided by failure mode of column. And then add lateral strength of each column after reduction, the result is the maximum base shear strength of building. Also, decides the ductility capacity of each column by its failure mode. The ductility capacity of building can be decided by the ductility capacity of each column weighted its lateral strength. Finally, using the ratio of seismic capacity and seismic demand can get the seismic performance of the building before detailed evaluation. Since Ultimate Moment Balanced Method consider both failure mode of strong beam weak column and strong column weak beam, the method can be used on old building either before or after retrofit. This paper takes Ruei Pu elementary school in Taoyuan county as an example to do Simplified Detailed Seismic Evaluation. It is proved that both maximum base shear and seismic capacity are conservative compared to in-situ test. So the method can be used on existing buildings for seismic evaluation. The Simplified Detailed Seismic Evaluation method can be used on establishing the preliminary evaluation method of buildings in addition to school buildings for engineers to application.
標題中高樓結構機率式倒塌風險評估法之應用研究
作者謝瑋桓、盧煉元、蕭輔沛、湯宇仕、黃尹男
關鍵字中高樓建築、機率式評估法、耐震性能評估、倒塌易損分析、風險評估、增量動力分析、非線性歷時分析
摘要都會區由於地狹人稠之故，建築物大多屬於中高樓結構，這些結構若於地震中倒塌或受損所造成的地震災害將不容小覷。因此對於老舊或因設計施工不良具潛在危險性之中高樓建物，吾人實有必要建立一套合理的耐震評估方法，以作為工程實務上篩檢與補強之依據。然而，現行建物評估法大多屬於定量式(deterministic)的非線性靜力側推分析法，此法對於低矮樓房或有其準確性，但卻不易預估中高樓結構高頻振態之反應，亦未能計及震波與設計及施工中所涵有的諸多不確定因子，因此評估結果有可能不夠保守。有鑑於此，本文旨在研議一實用之機率式建物倒塌耐震評估方法與流程，該方法乃結合美國FEMA P-58 之倒塌易損分析法、非線性增量式動力分析法與地震危害度分析法等，以計及結構在強震下的非線性動態特性及地震力的不確定性等項因子。惟因FEMA P-58 對於建物倒塌的判定準則與倒塌性能指標的選擇並無明確的建議。因此，本文乃參採PEER-TBI 與ASCE 41-13 技術報告針對RC 構造建議二項倒塌判定準則，分別稱為「總體結構」與「局部構件」倒塌判定準則。而在倒塌性能指標的訂定方面則參採ASCE 7-10 及FEMA P695建議之倒塌機率容許值，亦即：「最大考量地震力之倒塌機率」小於10%及「50年內倒塌超越機率」小於1%，作為判定建物是否有倒塌疑慮之標準。其中，前者之最大考量地震力可採用我國設計規範之值，十分方便實務之應用；而後者則須配合工址所在之地震危害度曲線加以計算，有利建物所有人作為承擔風險決策之用。最後，再以一實際倒塌的中高樓建物案例說明本文所建議倒塌性能評估法之執行程序。
TitleProbabilistic assessment of seismic performance and collapse risk for mid-rise buildings
AuthorWei-Huan Hsieh, Lyan-Ywan Lu, Fu-PeiHsiao, Yu-Shi Tang, Yin-Nan Huang
KeywordsWei-Huan Hsieh, Lyan-Ywan Lu, Fu-PeiHsiao, Yu-Shi Tang, Yin-Nan Huang Mid-rise building, seismic performance assessment, probabilistic assessment, collapse fragility analysis, risk assessment, incremental dynamic analysis, nonlinear time history analysis
AbstractMid-rise buildings, which are usually heavily populated, are very common structures in urban areas. The casualty and social impact caused by the collapse of mid-rise buildings in an earthquake can not be overestimated. Therefore, developing suitable assessment methods to identify the buildings with high collapse risk becomes a critical issue. Even though traditional seismic assessment methods, which usually employ nonlinear static pushover analysis, have been successfully applied to regular low-rise buildings, these methods are unable to reflect higher-mode effect on the responses of mid-rise buildings. Furthermore, a traditional approach usually leads to a deterministic result that could not account for the uncertainty in seismic motions and structural responses of a mid-rise building, which is usually more complicated and involves more structural uncertainties than a low-rise building. To this end, this paper presents a procedure and methodology to assess the collapse risk of a mid-rise building. This methodology is developed based on the collapse fragility analysis proposed by FEMA P-58, the collapse criteria proposed by PEER-TBI and ASCE 41-13, and acceptance criteria suggested by ASCE 41-13 and FEMA 356. To establish the fragility curves, this approach employs nonlinear time history analysis together with the method of incremental dynamic analysis (IDA) to estimate structural response parameters. Finally, for demonstration, the proposed assessment method is applied to assess the collapse risk of a mid-rise building that collapsed in an earthquake.

Vol.33/No.2 (130) (2018)

作者:

Vol.33/No.2 (130) (2018)

TitleImproving Seismic Performance of Hollow Steel Reinforced Concrete Members with Inclined Bars
AuthorHsieh-Lung Hsu, Ming-Te Hong
Keywordssteel reinforced concrete, flexural-torsional behavior, inclined bars
AbstractThis study focused on the improvement of flexural-torsional behavior of hollow composite members subjected to eccentric cyclic loads. A series of composite members composed of encased steel tubes and reinforced concrete with various inclined bars were fabricated for testing. Member performance was evaluated by the strength, stiffness and energy dissipation during the loading history. Test results showed that the strength of members with inclined bars was significantly increased when subjected to torsion and combined loading coupled with torsion. Enhancement in energy dissipation further validated the applicability of incline bars to the performance improvement of hollow composite members.
TitleThe Effect of Different Transverse Reinforcement Schemes on the Confinement of Encased Concrete-Filled Box Columns
AuthorCheng-Cheng Chen, Pin-Da Wu, Jia-Xi Zhou
KeywordsEncased Concrete-Filled Steel Box Columns, steel reinforced concrete column, SRC column, encased box column, concrete filled box column.
AbstractThe concrete in a concrete-filled steel box column is confined by the box column. However, the confinement of the concrete outside the box column(referred as outer concrete hereafter) in an encased concrete-filled box column need to be provided by the steel cage which is composed of main reinforcement and transverse reinforcement. Due to the existence of the steel box column, the traditional ties used in RC columns can note be implemented here. In this article, the confinement effect of so called corner tie, combined tie and lateral tie are investigated experimentally. Ten large-sized concrete-encased concrete-filled steel box short columns were tested under monotonic axial compression. Based on the test results obtained, the following conclusions are made: (a) the corner tie was unable to provide sufficient lateral support to the longitudinal bar and corner concrete that required by the design code; (b) the use of combined tie can provide sufficient confinement to the outer concrete, (c) the potential of lateral tie in providing sufficient confinement to the outer concrete is high, however, further research is needed to confirm it.
TitleStudy on Short-Stroke Damper Assembled in Tuned Mass Damper
AuthorYong-An Lai, Fan-Yen Meng, Kuan-Hua Lien, Lap-Loi Chung
Keywordstuned mass damper, short-stroke damper, optimal design, damper stroke
AbstractIn the conventional tuned mass damper (TMD), the damper stroke and the mass stroke must be the same, thus the long-stroke dampers are required for implementation in TMD. In addition, a considerable size and higher precision for manufacture of long-stroke damper majorly cause expensive budget for installation and maintenance of the TMD. According to the above features, the“Short-Stroke Damper assembled in Tuned Mass Damper (SSD-TMD)” is proposed in order to reduce the damper stroke in the TMD. In the SSD-TMD, the stiffness of SSD-TMD is separated into two parts. The first part is connected with the viscous damper in parallel. Then, the paralleled system is connected with the stiffness of the second part in series. Afterwards, the mass block is further attached to form the SSD-TMD. This assemblage will produce different strokes between the damper and the mass so that the damper stroke can be significantly mitigated under appropriate design of the stiffnesses and damping coefficient. In this article, the model of the SSD-TMD is firstly proposed. The design formulae and procedure of the SSD-TMD is also proposed by following the optimal design parameters for conventional TMD. The case study of the Taipei 101 structure implemented with the SSD-TMD shows that the damper stroke of the SSD-TMD can be dramatically reduced, so that the short-stroke dampers can be used to replace the long-stroke dampers. Furthermore, with suitable design of the SSD-TMD, both effectiveness of structural vibration reduction and mass stroke of the SSD-TMD can outperform the conventional TMD.
TitleSimplified Seismic Evaluation Method on Old Buildings
AuthorYu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Yao-Sheng Yang, Chien-Chuang Tseng, Sheng-Hsueh Lin, Chu-Yuan Chang
Keywordsseismic evaluation, maximum base shear, in-situ test
AbstractThe earthquakes happen in Taiwan, such as Chi-Chi earthquake, let us know seismic capacity of old buildings is not enough. Because it may cause casualty, it is important to raise seismic ability of those old buildings. School buildings belong to public facility and provide people shelters when their home are damaged seriously by earthquake. Therefore their seismic ability should be raised as soon as possible. National Center for Research on Earthquake Engineering (NCREE) proposed complete procedures for seismic evaluation. The procedures of seismic evaluations include: simple survey, preliminary evaluation and detailed evaluation. After screening out school buildings which have less seismic capacity than seismic demand, we need to do seismic retrofit for them. However, there are lots of other old buildings in Taiwan (such as street houses, hospitals and executive agency) need to raise their seismic ability. In this paper, the method use Ultimate Moment Balanced Method to do Simplified Detailed Seismic Evaluation is proposed. The method first evaluates the lateral strength of each column line and multiplied by reduction factor which decided by failure mode of column. And then add lateral strength of each column after reduction, the result is the maximum base shear strength of building. Also, decides the ductility capacity of each column by its failure mode. The ductility capacity of building can be decided by the ductility capacity of each column weighted its lateral strength. Finally, using the ratio of seismic capacity and seismic demand can get the seismic performance of the building before detailed evaluation. Since Ultimate Moment Balanced Method consider both failure mode of strong beam weak column and strong column weak beam, the method can be used on old building either before or after retrofit. This paper takes Ruei Pu elementary school in Taoyuan county as an example to do Simplified Detailed Seismic Evaluation. It is proved that both maximum base shear and seismic capacity are conservative compared to in-situ test. So the method can be used on existing buildings for seismic evaluation. The Simplified Detailed Seismic Evaluation method can be used on establishing the preliminary evaluation method of buildings in addition to school buildings for engineers to application.
TitleProbabilistic assessment of seismic performance and collapse risk for mid-rise buildings
AuthorWei-Huan Hsieh, Lyan-Ywan Lu, Fu-PeiHsiao, Yu-Shi Tang, Yin-Nan Huang
KeywordsWei-Huan Hsieh, Lyan-Ywan Lu, Fu-PeiHsiao, Yu-Shi Tang, Yin-Nan Huang Mid-rise building, seismic performance assessment, probabilistic assessment, collapse fragility analysis, risk assessment, incremental dynamic analysis, nonlinear time history analysis
AbstractMid-rise buildings, which are usually heavily populated, are very common structures in urban areas. The casualty and social impact caused by the collapse of mid-rise buildings in an earthquake can not be overestimated. Therefore, developing suitable assessment methods to identify the buildings with high collapse risk becomes a critical issue. Even though traditional seismic assessment methods, which usually employ nonlinear static pushover analysis, have been successfully applied to regular low-rise buildings, these methods are unable to reflect higher-mode effect on the responses of mid-rise buildings. Furthermore, a traditional approach usually leads to a deterministic result that could not account for the uncertainty in seismic motions and structural responses of a mid-rise building, which is usually more complicated and involves more structural uncertainties than a low-rise building. To this end, this paper presents a procedure and methodology to assess the collapse risk of a mid-rise building. This methodology is developed based on the collapse fragility analysis proposed by FEMA P-58, the collapse criteria proposed by PEER-TBI and ASCE 41-13, and acceptance criteria suggested by ASCE 41-13 and FEMA 356. To establish the fragility curves, this approach employs nonlinear time history analysis together with the method of incremental dynamic analysis (IDA) to estimate structural response parameters. Finally, for demonstration, the proposed assessment method is applied to assess the collapse risk of a mid-rise building that collapsed in an earthquake.

第三十三卷第一期 (期別129) (107年)

作者:

第三十三卷第一期 (期別129) (107年)

標題新竹科學園區1990年代之十層樓鋼構造標準廠房微振動長期監測及耐震能力評估
作者周中哲、曾冠霖、凌郁婷
關鍵字新竹鋼構造標準廠房、微振動、耐震能力、非韌性抗彎矩接頭
摘要新竹科學園區建立於1979年，為臺灣重要經濟支柱，然而臺灣地震頻繁，平時的微振動影響廠內精密儀器的精度以及製程良率，中小型地震下可能造成儀器損壞；強震則可能造成結構物破壞，危及廠內生命財產。為瞭解各種等級振動對既有廠房的影響，本研究在科技部的補助下以新竹科學園區內於1991年完成設計，1995年完工的第一座鋼構造高層標準廠房進行長期微振動監測以及耐震能力評估；監測系統蒐集該廠房2015年1月至2015年10月的微振動資料，並分析微振動等級及來源，監測期間收集多次中小型地震紀錄，並涵蓋數次的強颱事件(如2015年蘇迪勒及杜鵑颱風)，瞭解結構物在地震力及風力擾動下的反應特性。為瞭解廠房是否滿足現行規範的耐震要求，本研究根據1989年臺灣建築技術規則與現行臺灣建築物耐震設計規範(2011)計算地震力，並利用長期監測資料校正廠房的數值分析模型，進行結構物非線性側推分析與設計地震力(DBE)及最大考量地震力(MCE)下的20組非線性地震歷時分析，評估此廠房耐震能力。
TitleLong-Term Micro-Vibration Monitoring and Seismic Performance Evaluation of an Existing 10-Story Steel Factory in Hsinchu Science Park
AuthorChung-Che Chou, Steven Tsuang, Yu-Ting Ling
KeywordsSteel factory, Micro-vibration, Seismic performance, Moment connection
AbstractThe Hsinchu Science Park was opening in 1979 and becomes a very important high-tech area in Taiwan to support the economic growth. This work supported by the MOST, Taiwan focused on the micro-vibration and seismic performance of an existing 10-story steel factory that was designed in 1991 and completed in 1995 in Hsinchu Science Park, Taiwan. A few velocity and acceleration meters were used to monitor the building micro-vibration and performance during earthquakes and typhoons. The monitoring duration is from January to October, 2015 while Typhoons Soudelor and Dujuan and several small earthquakes hit the building. The recorded data was used to (1) evaluate the factory performance in terms of micro-vibration in vertical and longitudinal directions, and (2) adjust the building computer model such as the fundamental period and damping ratio. Then, the nonlinear pushover analysis and time history analyses were conducted on the factory model to obtain seismic demands on design-based and maximum-considered earthquake levels.
標題鋼筋混凝土柱最大可能彎矩強度
作者歐昱辰、蔡東均
關鍵字鋼筋混凝土、柱、最大可能彎矩強度、高強度、軸力
摘要在耐震設計中，吾人須求取柱之最大可能彎矩強度Mprc，以進行剪力容量設計。所謂最大可能彎矩強度為斷面在考慮材料超強效應（真實強度大於標稱強度、混凝土圍束效應、鋼筋應變硬化等）與各種設計軸力作用下所可能產生的最大彎矩。現行混凝土結構設計規範與橋梁耐震設計規範各設有一套最大可能彎矩強度計算方法，過去研究顯示此二法之保守程度會隨軸壓力比之增加而降低，其中又以壓力控制斷面之柱構件尤其明顯。為確認前述現象，本研究計算297 組柱試驗彎矩強度與標稱彎矩強度之比值，經比對後發現該比值與軸壓力比呈顯著正相關，相符於過去研究結果。為確認前述現象之主因，本研究進一步以數學式推導證明混凝土圍束效應會使此現象發生。考量此現象，本研究發展一套最大可能彎矩強度建議通用式，在材料實測強度已知的情況下，可通用於普通強度與高強度柱構件最大可能彎矩強度之計算。為驗證建議通用式之保守性，本研究計算柱之最大可能彎矩強度，結果顯示混凝土結構設計規範於多數柱呈現不保守，現行橋梁耐震設計規範則顯著改善此現象，然而對高軸壓力比之試體仍普遍得不保守計算結果，本研究建議通用式則可滿足規範一般對保守程度之要求，變異性亦屬三個算法中最低者。另外，為便於設計時使用，本研究另發展兩套最大可能彎矩強度建議式，在僅知材料規定強度的情況下，分別適用於普通強度與高強度柱構件。此二建議式經比對發現可得相近於建議通用式的計算結果。
TitleMaximum probable moment strengths of reinforced concrete columns
AuthorYu-Chen Ou, Tung-Chun Tsai
Keywordsreinforced concrete, columns, maximum probable moment strength, high strength, axial force
AbstractIn seismic design, the maximum probable moment strengths of columns need to be calculated for shear design. The maximum probable moment strength is the maximum possible moment strength considering material overstrengths (e.g. actual strengths higher than specified ones, concrete confinement, strain hardening of reinforcement, etc.) and the range of factored axial load acting on the column. Both the codes for design of reinforced concrete structures and seismic design of bridges have include their own provisions to calculate the maximum probable moment strength. Earlier studies have shown that both the code methods tend to show unconservative results with increasing axial compression, particularly for compression-controlled sections. In this research, the ratios of measured moment strength to nominal moment strength of 297 column specimens were examined. The examination confirmed that the ratios increased with increasing axial compression and found that it is mainly due to the effect of concrete confinement. To account for the phenomenon, a general equation for maximum probable moment strength of normal and high-strength columns was developed based on actual material strengths. Comparison with the test data of the 297 columns showed that the proposed equation produced conservative predictions for most of the columns. In contrast, current code equations for reinforced concrete structures and for seismic design of bridges produced unconservative predictions for most of the columns. Moreover, the predictions by the proposed equation showed smaller standard deviation than those by the current code methods. Based on the general equation, two equations were developed based on specified material strengths for normal and high-strength columns. Comparison with the test data of the 297 columns showed the two equations produced results similar to the proposed general equation.
標題含開口鋼筋混凝土牆非韌性構架試驗研究
作者曾建創、陳力平、黃世建
關鍵字鋼筋混凝土、開口剪力牆、開窗、開門、剪力強度、試驗研究
摘要本研究設計了六座對台灣低矮型建築具代表性之含開口鋼筋混凝土牆非韌性構架試體，於國家地震工程研究中心（National Center for Research on Earthquake Engineering, NCREE）進行試驗。共規劃三個系列，每個系列各二座試體：單一開窗試體、雙開窗試體以及單一開門試體。實驗結果顯示，開窗寬度較小的試體，因保有翼牆的特性，其翼牆能讓剪力強度明顯提昇。雙開窗試體，於兩開窗中間的垂直牆段，其強度的貢獻，與其高長比有明顯的差異。而單一開門系列的試體，其開門上方所增加的垂壁，對試體的剪力強度提昇效果不大，但會因開門兩側垂直牆段的高長比，明顯影響試體的韌性表現。關於含開口鋼筋混凝土牆的剪力強度計算，ACI 318-14 規範中已有明確的計算公式，本文利用ACI 318 的建議公式來計算剪力強度並與實驗值作比較，以驗證ACI 318-14 規範針對含開口RC 牆的剪力強度預測之適用性。
TitleExperimental Study of Non-ductile Frame Infilled with RC Shear Wall with Openings
AuthorChien-Chuang Tseng, Li-Ping Chen, Shyh-Jiann Hwang
Keywordsreinforced concrete, shear wall with openings, window openings, door openings, shear strength, experimental study
AbstractIn this study, six specimens of non-ductile RC infilled frames with openings were designed according to the typical low-rise buildings in Taiwan, and these specimens were tested in NCREE. Specimens were categorized into three series, such as single window opening, double window openings and single door opening, and each series has two specimens. Test results indicated that the smaller width of window opening can increase shear strength significantly due to the contribution of wing wall. For the specimens of double window openings, shear strength of vertical wall segments between two window openings is significantly lower as compared with its height-to-length ratio. For the specimens of single door opening, the experimental results showed shear strength only increased slightly by its overhanging wall. In addition, it was indicated that the ductility of the specimen is significantly improved because the larger vertical dimension of door opening can yield higher height-to-length ratio of vertical wall segment. ACI 318-14 building code has equations to predict the shear strength of RC wall with openings. In this paper, ACI 318 building code was used to calculate shear strength and compared with the experimental results to check the applicability of ACI 318-14 code on predicting the shear strength of RC wall with openings applicability.
標題採托架支承配置挫屈束制支撐之新建RC構架設計、試驗與抗震性能分析
作者林庭立、吳安傑、王孔君、蔡克銓
關鍵字挫屈束制支撐、鋼筋混凝土結構、托架、梁柱接頭、非線性動力歷時分析
摘要本文針對採Z 字形（zigzag）配置挫屈束制支撐（buckling-restrained brace,BRB）於新建鋼筋混凝土（reinforced concrete, RC）構架中的接合介面進行探討，依據現行耐震設計規範提出一棟含BRB 之12 層樓RC 結構設計例。為了解所提接合方式之施工性與耐震性能，擷取設計例中位於10 樓的RC梁柱接頭處進行細部設計，並製作含接合板基座及托架之實尺寸梁與柱節點子結構試體進行反覆載重試驗。試驗結果顯示，接頭處之接合板基座及托架未發生明顯損壞，可有效傳遞BRB 與RC 構架間的力量，並證實所提接合方式之設計與施工方法可供工程實務應用。為更進一步探討整體結構系統受震反應，本研究採用三種地震危害度（SLE, DBE and MCE）共240組含近斷層之地震加速度歷時進行非線性動力歷時分析。分析結果顯示，整體結構系統高模態振動反應並不顯著，三種危害度地震下BRB 最大抗層間側力比例平均值分別為23%（SLE）、21%（DBE）及19%（MCE）；DBE及MCE 等級地震下，最大層間側位移角則分別為0.0182 及0.0232 弧度。此外，接合板基座之最大水平向拉力需求可採相鄰兩組BRB 可能發展之最大拉力強度水平向合力之70%進行設計。
TitleSeismic Design and Tests of the Beam-column Joint in a Buckling-Restrained RC Braced Frame
AuthorTing-Li Lin, An-Chien Wu, Kung-Juin Wang, Keh-Chyuan Tsai
Keywordsbuckling-restrained brace, reinforced concrete structure, corbel, beam-column joint, nonlinear response history analysis
AbstractIn this study, the brace connection performance in the new reinforced concrete (RC) frame buildings with buckling-restrained braces (BRBs) arranged in a zigzag configuration is investigated. A 12-story buckling-restrained braced RC building is proposed following the model building codes as a prototype. In order to verify the constructability and the seismic performance of the proposed connection, the beam-column joint at the tenth floor selected as the sub-assemblage specimen was designed and fabricated. The full-scale sub-assemblage, including the BRB gusset bracket and a pair of RC corbels, in the proposed BRB-RCF structural system was tested using cyclic loading procedure. Test results demonstrate that the proposed BRB-to-RC connection details performed very well without failure in the steel gusset bracket or the RC corbels. The design and construction of the sub-assemblage specimen show the feasibility of the proposed system for practical applications. In order to further gain insights into the seismic performance of the BRB-RCF system, nonlinear response history analyses were conducted using a total of 240 (SLE, DBE and MCE) ground accelerations. Analysis results indicate that the mean maximum total BRB shear to base story shear ratios are about 23%, 21% and 19% for SLE, DBE and MCE, respectively. The maximum inter-story drift ratios under the DBE and MCE events are 1.82% and 2.32%, respectively. Analysis results also suggest that the high mode effect is moderate. It is found that the peak demand of the horizontal tension force on the gusset bracket can be estimated by considering 70% of the sum of the horizontal force components computed from the maximum tension strengths of two adjacent BRBs.
標題台灣混凝土潛變收縮資料庫建置及特質分析
作者陳振川、廖文正、劉庭愷、秦維邑
關鍵字混凝土、潛變、收縮、高爐石粉、飛灰、資料庫
摘要本研究彙整台灣近半世紀潛變及收縮試驗資料，參考國際上資料庫的參數組成及資料架構，並與前所建立台灣既有混凝土資料庫結合，建立「台灣混凝土潛變收縮資料庫」。其中收錄82 篇文獻，包含潛變試驗156 組及收縮試驗303 組，並對於其材料性質、配比、摻料用量、試體幾何、養護條件等試驗情況皆有紀錄。本研究透過與文獻探討和國際資料庫資料的分析比較，證實台灣混凝土配比設計中，在相同設計強度目標，具有使用高水泥量及漿體量，及使用彈性模數較低之本土粒料的特性。最後，本文成果除了將台灣資料庫併入世界混凝土資料庫，並可用以建立台灣混凝土潛變與收縮預測公式，亦期望能奠定世界資料庫發展至雲端化、網頁化之基礎。
TitleDevelopment and Analysis of Creep and Shrinkage Database of Concrete in Taiwan
AuthorJenn-Chaun Chern, Wen-Cheng Liao, Ting-Kai Liu, Wei-Yi Chin
KeywordsConcrete, Creep, Shrinkage, Slag, Fly Ash, Database
AbstractThe present study begins with the organization of recent half a century data on the shrinkage and creep testing, and proceeds to refer the parameter formation and data structure in international databases, and combines those with present concrete databases in Taiwan to create the Database on Creep and Shrinkage of Taiwan Concrete. The database incorporates 82 documents, 156 data sets for concrete creep tests, and 303 data sets for concrete shrinkage tests. The material properties, the mix designs, the admixture amounts, the geometry of the test specimens, and the test conditions, for each test, are well documented in this database. Through comparisons with international database analyses and literature reviews, this study has verified that the mix design of concrete in Taiwan, for comparable design strength targets, tends to have the following characteristics: high cement amounts, and low elastic moduli of local aggregate. Finally, this study, in addition to incorporating the Taiwan database into the international concrete databases, is also expected to serve as a base to facilitate the development of the worldwide database with a cloud-based web platform for the world.

Vol.33/No.1 (129) (2018)

作者:

Vol.33/No.1 (129) (2018)

Title Long-Term Micro-Vibration Monitoring and Seismic Performance Evaluation of an Existing 10-Story Steel Factory in Hsinchu Science Park
Author Chung-Che Chou, Steven Tsuang, Yu-Ting Ling
Keywords Steel factory, Micro-vibration, Seismic performance, Moment connection
Abstract The Hsinchu Science Park was opening in 1979 and becomes a very important high-tech area in Taiwan to support the economic growth. This work supported by the MOST, Taiwan focused on the micro-vibration and seismic performance of an existing 10-story steel factory that was designed in 1991 and completed in 1995 in Hsinchu Science Park, Taiwan. A few velocity and acceleration meters were used to monitor the building micro-vibration and performance during earthquakes and typhoons. The monitoring duration is from January to October, 2015 while Typhoons Soudelor and Dujuan and several small earthquakes hit the building. The recorded data was used to (1) evaluate the factory performance in terms of micro-vibration in vertical and longitudinal directions, and (2) adjust the building computer model such as the fundamental period and damping ratio. Then, the nonlinear pushover analysis and time history analyses were conducted on the factory model to obtain seismic demands on design-based and maximum-considered earthquake levels.
TitleMaximum probable moment strengths of reinforced concrete columns
AuthorYu-Chen Ou, Tung-Chun Tsai
Keywordsreinforced concrete, columns, maximum probable moment strength, high strength, axial force
AbstractIn seismic design, the maximum probable moment strengths of columns need to be calculated for shear design. The maximum probable moment strength is the maximum possible moment strength considering material overstrengths (e.g. actual strengths higher than specified ones, concrete confinement, strain hardening of reinforcement, etc.) and the range of factored axial load acting on the column. Both the codes for design of reinforced concrete structures and seismic design of bridges have include their own provisions to calculate the maximum probable moment strength. Earlier studies have shown that both the code methods tend to show unconservative results with increasing axial compression, particularly for compression-controlled sections. In this research, the ratios of measured moment strength to nominal moment strength of 297 column specimens were examined. The examination confirmed that the ratios increased with increasing axial compression and found that it is mainly due to the effect of concrete confinement. To account for the phenomenon, a general equation for maximum probable moment strength of normal and high-strength columns was developed based on actual material strengths. Comparison with the test data of the 297 columns showed that the proposed equation produced conservative predictions for most of the columns. In contrast, current code equations for reinforced concrete structures and for seismic design of bridges produced unconservative predictions for most of the columns. Moreover, the predictions by the proposed equation showed smaller standard deviation than those by the current code methods. Based on the general equation, two equations were developed based on specified material strengths for normal and high-strength columns. Comparison with the test data of the 297 columns showed the two equations produced results similar to the proposed general equation.
Title Experimental Study of Non-ductile Frame Infilled with RC Shear Wall with Openings
Author Chien-Chuang Tseng, Li-Ping Chen, Shyh-Jiann Hwang
Keywords reinforced concrete, shear wall with openings, window openings, door openings, shear strength, experimental study
Abstract In this study, six specimens of non-ductile RC infilled frames with openings were designed according to the typical low-rise buildings in Taiwan, and these specimens were tested in NCREE. Specimens were categorized into three series, such as single window opening, double window openings and single door opening, and each series has two specimens. Test results indicated that the smaller width of window opening can increase shear strength significantly due to the contribution of wing wall. For the specimens of double window openings, shear strength of vertical wall segments between two window openings is significantly lower as compared with its height-to-length ratio. For the specimens of single door opening, the experimental results showed shear strength only increased slightly by its overhanging wall. In addition, it was indicated that the ductility of the specimen is significantly improved because the larger vertical dimension of door opening can yield higher height-to-length ratio of vertical wall segment. ACI 318-14 building code has equations to predict the shear strength of RC wall with openings. In this paper, ACI 318 building code was used to calculate shear strength and compared with the experimental results to check the applicability of ACI 318-14 code on predicting the shear strength of RC wall with openings applicability.
Title Seismic Design and Tests of the Beam-column Joint in a Buckling-Restrained RC Braced Frame
Author Ting-Li Lin, An-Chien Wu, Kung-Juin Wang, Keh-Chyuan Tsai
Keywords buckling-restrained brace, reinforced concrete structure, corbel, beam-column joint, nonlinear response history analysis
Abstract In this study, the brace connection performance in the new reinforced concrete (RC) frame buildings with buckling-restrained braces (BRBs) arranged in a zigzag configuration is investigated. A 12-story buckling-restrained braced RC building is proposed following the model building codes as a prototype. In order to verify the constructability and the seismic performance of the proposed connection, the beam-column joint at the tenth floor selected as the sub-assemblage specimen was designed and fabricated. The full-scale sub-assemblage, including the BRB gusset bracket and a pair of RC corbels, in the proposed BRB-RCF structural system was tested using cyclic loading procedure. Test results demonstrate that the proposed BRB-to-RC connection details performed very well without failure in the steel gusset bracket or the RC corbels. The design and construction of the sub-assemblage specimen show the feasibility of the proposed system for practical applications. In order to further gain insights into the seismic performance of the BRB-RCF system, nonlinear response history analyses were conducted using a total of 240 (SLE, DBE and MCE) ground accelerations. Analysis results indicate that the mean maximum total BRB shear to base story shear ratios are about 23%, 21% and 19% for SLE, DBE and MCE, respectively. The maximum inter-story drift ratios under the DBE and MCE events are 1.82% and 2.32%, respectively. Analysis results also suggest that the high mode effect is moderate. It is found that the peak demand of the horizontal tension force on the gusset bracket can be estimated by considering 70% of the sum of the horizontal force components computed from the maximum tension strengths of two adjacent BRBs.
Title Development and Analysis of Creep and Shrinkage Database of Concrete in Taiwan
Author Jenn-Chaun Chern, Wen-Cheng Liao, Ting-Kai Liu, Wei-Yi Chin
Keywords Concrete, Creep, Shrinkage, Slag, Fly Ash, Database
Abstract The present study begins with the organization of recent half a century data on the shrinkage and creep testing, and proceeds to refer the parameter formation and data structure in international databases, and combines those with present concrete databases in Taiwan to create the Database on Creep and Shrinkage of Taiwan Concrete. The database incorporates 82 documents, 156 data sets for concrete creep tests, and 303 data sets for concrete shrinkage tests. The material properties, the mix designs, the admixture amounts, the geometry of the test specimens, and the test conditions, for each test, are well documented in this database. Through comparisons with international database analyses and literature reviews, this study has verified that the mix design of concrete in Taiwan, for comparable design strength targets, tends to have the following characteristics: high cement amounts, and low elastic moduli of local aggregate. Finally, this study, in addition to incorporating the Taiwan database into the international concrete databases, is also expected to serve as a base to facilitate the development of the worldwide database with a cloud-based web platform for the world.

第三十二卷第四期 (期別128) (106年)

作者:

第三十二卷第四期 (期別128) (106年)

標題 化學植筋在低強度混凝土中剪力行為研究
作者 許家銘、鄭元良、蕭輔沛、廖文義、翁樸文、李台光、黃國倫
關鍵字 低強度混凝土、化學錨栓、植筋、剪力、補強
摘要 植筋工程常被用於結構物補強工程中，如翼牆及剪力牆補強等工法，藉由對既有結構體進行植筋，將補強結構體與既有結構體相連接，以期發展出良好的耐震行為。國家地震工程研究中心於校舍補強案例中，發現老舊校舍結構常有混凝土強度偏低的問題，其平均混凝土強度約為17 MPa，甚至有低至5 MPa 左右之案例，因此本研究探討低強度混凝土中植筋剪力行為，並探討現行ACI 混凝土設計規範之適用性。本研究在混凝土強度分別為5MPa、10 MPa 及15 MPa 之混凝土試體中，進行一系列的植筋單向剪力測試，試體共計有192 組，試驗控制參數包含植筋深度、邊距及混凝土強度。試驗結果與ACI 規範計算值相比較後，發現ACI 計算值在強度10MPa 和15MPa 之試體仍屬保守，但在5MPa 試體之試驗值則與計算值相當接近，故ACI 規範錨定計算公式應用於極低強度混凝土中可能會有不保守情況產生。此外，實驗發現有一種在低強度混凝土中的破壞模式屬鋼筋彎曲破壞，其強度介於邊距破壞與鋼筋剪斷之間，有別於ACI 規範中所考慮之邊距、撬破和鋼筋剪斷三種破壞模式。最後，本文以國內實際RC 剪力牆試驗與震害勘災結果，說明混凝土植筋界面剪力強度之重要性。
Title Study on the Shear Behavior of Chemical Anchors in the Low Strength Concrete
Author Jia-MingHsu, Yuan-Liang Zheng, Fu-Pei Hsiao, Wen-I Liao, Pu-Wen Weng, Tai-Kuang Lee, Guo-Luen Huang
Keywords low strength concrete, adhesiveanchors, post-installed rebars, shear, retrofit
Abstract In 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.
標題震害橋梁載重試驗之分析
作者陳俊仲、宋裕祺、張峰愷、邱毅宗、李政寬、許家銓、葉芳耀、黃炳勳、陳嘉盈、吳萬龍
關鍵字遺傳演算法、反應曲面法、車載試驗
摘要本文以震害橋梁載重試驗為研究分析案例，採用有限元素分析軟體建構橋梁結構模型，並依車輛載重現地試驗量測成果，瞭解橋梁於試驗現況之結構基本特性，用以回饋分析模型設定參數調校參考，目的為確保建構之結構分析模型可詳實反映真實橋梁基本結構特性與輸出反應。由於建置可靠之結構分析模型，考量各受載情境下推估結構可能的真實反應，是訂定橋梁長期監測與管養量化參數主要應用參考方法，惟真實橋梁結構構件與系統複雜度高，欲完整詳實模擬真實橋梁結構，通常可利用現地橋梁試驗量測得真實結構反應，並據以適當調校結構分析模型參數，讓分析模型反應接近真實結構反應。一般而言必須採用足夠多的分析元素才能得到較具代表性的結構分析模型，因此在調校模型參數過程配合反覆演算需求，經常遇到調校過程分析效率不佳或無法完成模型參數調校目的。因此本研究應用實驗設計方法，建立反應曲面函數以代表原有限元素分析模型，並針對反應曲面函數參數，配合遺傳演算法進行分析模型選定之設定參數最佳化，透過最佳化後之反應曲面函數，取得最佳之分析模型材料設定參數。本研究方法可有效提升結構分析模型參數調校之效率，提高分析模型相對真實結構之代表性，近而將分析模型應用於結構長期監測與健康診斷系統之安全資訊評估。
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.
標題鋼筋混凝土建築物耐震能力初步評估系統PSERCB之建置與應用
作者宋裕祺、蔡益超、陳建忠、賴明俊、邱毅宗、陳俊榕、林宏軒、陳長佑、顏志良
關鍵字雲端作業系統、定量評估、防災
摘要老舊建築物或因設計年代久遠或因現況不佳等因素，其耐震能力恐未能符合現行規範標準。若逐一進行詳細耐震能力評估，將耗費相當龐大的經費與時間。本文根據內政部建築研究所2014 年委託研究計畫所制定的新版建築物耐震能力初步評估方法為基礎，開發出鋼筋混凝土建築物耐震能力初步評估系統(Preliminary Seismic Evaluation of RC Building, PSERCB)，讓使用者能夠快速且不失準確的估算建築物的耐震能力。PSERCB 能夠將耐震能力初步評估結果以定性與定量方式呈現，並以分數表示，讓評估者能夠判別建築物耐震能力之情況，作為後續是否須執行耐震詳細評估與補強或者是拆除重建之參考依據。本系統採雲端作業方式，評估者之調查資料將儲存於雲端資料庫內，可提供各級政府資料檢視、分析、統計與管理之用，並可作為擬訂防災策略所需大數據(Big Data)分析之依據，達到災害控管的目的。
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.
標題立面不規則建築受震反應簡化分析方法
作者曹智嘉、林瑞良、蔡克銓
關鍵字立面不規則建築、退縮、非線性反應歷時分析、振態側推分析、振態反應歷時分析
摘要耐震規範中對立面不規則建築有其定義與限制，並且要求須以動力分析方法進行結構設計。除了以有限元素分析法(finite element method, FEM)進行全結構的非彈性動力分析外，振態側推分析法(modal pushover analysis method)是常用的簡化分析方法之一。進行振態側推分析可以得到各振態的非彈性受力與變形關係，由此受力與變形關係可以建立代表該振態的單自由度振態系統。再進行各單自由度振態系統的非線性反應歷時分析，並將各振態造成的反應歷時相加，即可求得結構的總反應，在本研究中稱此簡化分析方法為單自由度振態分析方法(single-degree-of-freedom modal analysis method,SDM)。相關文獻顯示SDM會高估底層或下半結構較強或較強且較硬之立面不規則建築之下部樓層的受震反應，建議對此類結構仍應採用較為複雜與耗時的FEM來分析其受震反應。然而此類型之立面不規則結構物常見於實際工程中，若能發展適合的簡化分析方法，則將有助於工程的應用。有鑒於單自由度振態系統無法反映上述類型結構上下兩部分顯著不同的受震反應， 本研究提出二自由度振態分析方法(two-degree-of-freedom modal analysis method,2DM)，將每個振態系統以兩個自由度分別代表上部及下部結構的振態反應，經由疊加各振態所造成的反應歷時以估算結構的總反應歷時。本研究以一棟9層樓及一棟20層樓規則平面抗彎矩構架做為原型建築，修改每一個原型建築成為四個立面不規則構架(底層較強、底層較強且較硬、下半結構較強、下半結構較強且較硬)做為研究之標的建築。以FEM、SDM及2DM分析上述八個立面不規則構架分別受到60筆地震記錄作用下的反應。本研究顯示當結構保持彈性，2DM與SDM分析結果完全相同；當結構進入非彈性，一般而言2DM估算的各樓層反應較SDM準確，能夠有效降低被SDM高估的下部結構的最大層間位移比。
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.
標題高層建築於干擾效應下氣動力及氣彈力實驗結果比較
作者羅元隆、陳紀柔
關鍵字高層建築、氣彈實驗、干擾效應、干擾因子
摘要風力對高層建築物的反應為高層建築物設計中重要的一環，本研究以建築物之間風力所造成的干擾效應影響比較為主要探討項目，比較氣動力實驗與氣彈力實驗結果在干擾效應影響下的差異性。實驗結果討論分為三個部分，第一部分為探討干擾效應下氣動力實驗─風壓量測法之建物整體平均風力係數、擾動風力係數與風力干擾因子；第二部分為探討干擾效應下氣彈力實驗─位移量測法之位移擾動值與位移干擾因子；第三部分為比較第一部分與第二部分之相同流場下不同實驗方法之干擾效應結果差異。在不同的實驗方法中所得到的結構擾動反應值之變化與不同干擾位置之影響甚大。且由氣彈力實驗結果中找出氣動力實驗無法預估的結構氣彈力現象。本研究期望能藉由兩種實驗方式指出結構物受干擾效應影響下可能發生的遮蔽效應及增幅效應隨著干擾位置變動，而有不同的結果。
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.