teacher 各位會員大家好， 以下2則演講訊息：
日期：108年08月26日(星期一) 時間：下午02:00～04:30
演講題目：Current Approaches for Assessing Uncertainty in PSHA: Examples from Recent SSHAC Studies
講者： Dr. William R. Lettis
服務機關：Lettis Consultants International
日期：108年8月29日(星期四) 時間：上午9:30～12:00
地點：國家地震工程研究中心R101演講廳
第一場演講題目：台中國家歌劇院結構設計
講者：張敬昌 副總經理 服務機關：永峻工程顧問股份有限公司
第二場演講題目：台中國家歌劇院施工
講者：黃明晴 副總經理
服務機關：麗明營造股份有限公司 本場專題演講無需報名與繳費，歡迎有興趣者踴躍參加。
中華民國結構工程學會 敬啟 108/08/19
「結構工程」季刊第133期(第34卷第1期)
電子檔已經上線。歡迎會員登入後下載全文。
中文網址: 第34卷第1期 (2019)
英文網址: Vol.34 / No.1 (2019)
若有任何意見歡迎 email 至 csse@csse.org.tw。
| 標題 | 雙向鋼板剪力牆邊界梁柱耐震設計與分析研究 |
|---|---|
| 作者 | 楊依璇、黃彤、李昭賢、蔡青宜、蔡克銓 |
| 關鍵字 | 三維鋼板剪力牆、邊界柱、容量設計、軸彎剪互制、有限元素模型分析、合成梁 |
| 摘要 | 針對雙向鋼板剪力牆底層角落邊界柱須抵抗兩正交向剪力牆之作用，本研究利用過去研究所提單向剪力牆底層邊界柱設計方法，考量雙向構架及鋼板共同造成之彎矩、剪力及軸力互制關係，設定底層柱塑鉸高程在0.3倍柱高，提出雙向鋼板剪力牆邊界柱設計方法。為驗證所提之設計方法，本研究利用四組兩層L 型平面之雙向鋼板剪力牆有限元素模型進行分析，分析結果顯示，所提設計方法可準確預測底層受壓邊界柱之雙向彎矩需求分佈與塑鉸發生位置。此外箱型邊界柱須承受與柱面垂直之鋼板拉力場作用力，柱面板厚不足時可能導致局部非線性變形，本研究亦探討雙向鋼板剪力牆交界處邊界箱型柱面外受拉力與變形之關係，並提出耐震設計方法。鋼板剪力牆頂層邊界梁構件須承受下方鋼板下拉力引致之正彎矩，本研究以有限元素分析探討邊界鋼寬翼梁與混凝土樓板合成之行為，分析結果顯示當合成梁受來自鋼梁下方之鋼板拉力，混凝土樓板與鋼梁之共同作用行為並不明顯，因此本研究建議設計時應保持一般鋼寬翼斷面梁之設計方法，僅考量鋼骨之彎矩強度。 |
| 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. |
| 標題 | 含鋼板阻尼器構架最佳化設計 |
|---|---|
| 作者 | 張舉虹、蔡克銓 |
| 關鍵字 | 鋼板阻尼器、耐震設計、容量設計、受剪挫屈、最佳化設計、抗彎構架 |
| 摘要 | 鋼板阻尼器(Steel Panel Damper, SPD)為三段式寬翼構件，中段為非彈性核心段，上下兩段為彈性連接段，在核心段配置加勁板，可延遲受剪挫屈的發生。在抗彎構架配置SPD，核心段腹板能反覆受剪降伏來消能，本研究利用MATLAB 最佳化工具箱，結合模擬退火法與梯度下降法成混合式演算法，考慮上下層SPD 相同且皆於梁跨中心，僅探討SPD、邊界梁與其交會區之設計，以最少SPD、加勁板、邊界梁全長、交會區疊合板與連續板總用鋼量為目標函數。SPD、加勁板、邊界梁斷面與交會區疊合板厚為設計變數；以滿足SPD、邊界梁與交會區容量設計、SPD 核心段加勁板設計及防止斷面局部與側向扭轉挫屈作為基本限制條件，研究最少用鋼量為「基本設計」。因SPD 勁度強度可分離，在固定強度下可增加勁度，然增加SPD或邊界梁勁度，皆能提升構架勁度，本研究根據反曲點取出SPD 與邊界梁十字子構架，在選定SPD 強度下，以子構架側向勁度增加50%為新增限制條件，再次進行最佳化設計，稱所得最少用鋼量為「1.5 倍勁度設計」。設計範例顯示在滿足基本限制條件下，只須增約9%用鋼量，即可達1.5 倍勁度設計。為提高勁度，主要以增加邊界梁深與腹板厚較有效，但將導致梁強度增加40%。另對梁強度增量設25%上限，發現須較基本設計增約11%用鋼量，才可得1.5 倍勁度設計。若另對梁深也設上限，須增約30%用鋼量，才可得1.5 倍勁度設計；此時梁強度為基本設計的1.2 倍。本研究也討論垂直載重對邊界梁設計之效應，並表列實際可供工程應用之最佳化SPD 與邊界梁的設計尺寸案例。 |
| 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. |
| 標題 | 鋼造自復位挫屈束制斜撐(SC-SBRB)發展及耐震試驗 |
|---|---|
| 作者 | 周中哲、蔡文璟、鍾秉庭 |
| 關鍵字 | 自復位挫屈束制斜撐、反覆載重、殘餘變形、能量消散 |
| 摘要 | 鋼造斜撐構架具有良好的耐震性能，然而在大變形下易使建築物產生結構損壞和殘餘變形，造成震後難以修復且費用昂貴，因此本文提出一種可提升建築物抗震能力的全新鋼造自復位挫屈束制斜撐(Self-Centering Sandwiched Buckling-Restrained Brace, SC-SBRB)，此種斜撐同時具有雙核心自復位斜撐的自復位能力及挫屈束制斜撐的消能能力，自復位能力是利用斜撐中的兩組拉力構件束制斜撐中的鋼受壓構件，使斜撐在大變形下具有回到零殘餘變形的能力；消能能力是利用兩組獨立分離的圍束構件以栓接方式束制斜撐中的核心構件，使得斜撐受壓不會挫屈而產生飽滿的遲滯消能。本文首先介紹兩組不同構件配置的自復位挫屈束制斜撐，說明其力學行為及抗震機制，以減少建築物受震的最大變形及殘餘變形，並於實驗室進行兩組長度7860 mm 的實尺寸斜撐試驗驗證其耐震性能，試驗結果顯示斜撐的傳力機制與理論預測相符，試驗亦證明兩組斜撐試體分別經歷共3 次反覆載重及52 圈疲勞載重測試下仍保持良好耐震能力，斜撐更可在層間側位移角2.5%而不破壞，最大軸力可達1700 kN，全部試驗的累積韌性容量可達1090-1129，超過美國耐震規範AISC (2010)的建議值200。 |
| Title | Development and Seismic Tests of Steel Self-Centering Sandwiched Buckling-Restrained Braces (SC-SBRBs) |
|---|---|
| Author | Chung-Che Chou, Wen-Jing Tsai, Ping-Ting Chung |
| Keywords | Self-centering sandwiched buckling-restrained brace (SC-SBRB), Cyclic test, Residual deformation, Energy dissipation |
| Abstract | Earthquake-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. |
| 標題 | 考量強地動特性之可變勁度隔震系統研發與應用 |
|---|---|
| 作者 | 劉政嘉、林子剛、盧煉元、蕭迦恩 |
| 關鍵字 | 勁度可變、速度能量、隔震系統、半主動控制、半主動控制、最佳動位能比例法 |
| 摘要 | 近年來，結構物隔減震研究日趨受到重視，過去的研究顯示隔減震效應無法即時判定地震類型，並針對近遠域地震特性改變以達到最佳控制效果。為了使控制效果最佳化，本研究開發一套半主動控制系統「地震能量預測比例法」(Feed-forward Predictive Earthquake Energy Analysis, FPEEA)，透過量測地震主波到來前之速度，計算頻率域之能量頻譜，進而區分出近遠域地震；並結合最佳動位能比例法(Minimal Energy Weighting, MEW)決定位能權重，以有效即時控制結構反應。本研究已開發完成此半主動控制理論， 搭配槓桿式可變勁度隔震系統(Leverage-type Stiffness Controllable Isolation System, LSCIS)，調整槓桿支點位置進而改變隔震層勁度，以達到最佳的隔減震效果。與過去的半主動控制律相比，本研究之控制律可達到與MEW相同之控制效果甚至更佳。實際振動台試驗結果顯示，透過速度能量判定可於主要震波來前區分出近遠域地震，達到即時控制效果。而針對近域地震情況下，更可有效降低隔震層位移，並對上部結構加速度反應有良好的控制成效。 |
| 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. |
| 標題 | 生命週期考量之鋼管混凝土建築結構合理設計分析法 |
|---|---|
| 作者 | 陳振川、吳子良 |
| 關鍵字 | 潛變、自體收縮、乾燥潛變、鋼管混凝土、結構設計 |
| 摘要 | 鋼管混凝土建築結構已經成為一種常用之建築型式，其搭配自充填混凝土之內填，對於增加高層建築物之承載及勁度均有助益，並增加建築面積之有效使用。然而，現有規範及設計採用複合材料設計方式，其結構設計和所充填混凝土之潛變收縮行為及混凝土與鋼材之互制現象，則未在現有建築工程設計充分考量。本研究介紹混凝土時間變形特性及應用本土潛變預測之必要性，並提出一從生命週期考量之鋼管混凝土建築結構設計分析法，並提出設計程序與案例分析，以確保在生命週期之使用年壽期間，結構物可提供長期結構安全及服務性。 |
| 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. |
| 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. |
| Title | Development and Seismic Tests of Steel Self-Centering Sandwiched Buckling-Restrained Braces (SC-SBRBs) |
|---|---|
| Author | Chung-Che Chou, Wen-Jing Tsai, Ping-Ting Chung |
| Keywords | Self-centering sandwiched buckling-restrained brace (SC-SBRB), Cyclic test, Residual deformation, Energy dissipation |
| Abstract | Earthquake-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. |
| 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。 |
| 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. |
| 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。 |
| 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. |
| 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。 |
| 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. |
| 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。 |
| 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. |
| 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。 |
| 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. |
| 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 |
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| 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. |
| 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。 |
| Title | The confinement effectiveness of transverse reinforcement in circular reinforced concrete columns |
|---|---|
| Author | Tai-Kuang Lee, Cheng-Cheng Chen |
| Keywords | Circular RC Columns, Transverse Reinforcement, Confinement Effectiveness |
| Abstract | In 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。 |
| Title | Use of Stress Wave methods for Nondestructive Inspection of Epoxy-Bonded Length of Post-installed Rebars in Concrete |
|---|---|
| Author | Kai-Chung Teng, Chiang-Lung Chuang, Yiching Lin, Guo-Ruei Jiang |
| Keywords | quality of planting bars, nondestructive evaluation, stress waves, impact-echo |
| Abstract | This 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。 |
| Title | Establishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( I ) :Basic Creep, Drying Creep and Total Creep |
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| Author | Ting-Kai Liu, Jenn-Chuan Chern |
| Keywords | Concrete, Long-term Deformation, Creep, Shrinkage, Database |
| Abstract | At 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。 |
| Title | Establishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( II ) : Drying Shrinkage, Autogenous Shrinkage and Total Shrinkage |
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| Author | Wei-Yi Chin, Jenn-Chuan Chern |
| Keywords | concrete, long-term deformation, shrinkage, blast-furnace slag cement, fly ash, dataset |
| Abstract | At 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。 |
| Title | Experimental Study of Reinforced Concrete Frame Filled with Low Masonry Window Spandrel |
|---|---|
| Author | Shuenn-Yih Chang, Ping-Chi Wu, Tsui-Huang Wu |
| Keywords | Reinforced Concrete Building, Low Masonry Window Spandrel, Seismic Evaluation, Pushover Analysis |
| Abstract | In 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. |
| Title | The confinement effectiveness of transverse reinforcement in circular reinforced concrete columns |
|---|---|
| Author | Tai-Kuang Lee, Cheng-Cheng Chen |
| Keywords | Circular RC Columns, Transverse Reinforcement, Confinement Effectiveness |
| Abstract | In 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. |
| Title | Use of Stress Wave methods for Nondestructive Inspection of Epoxy-Bonded Length of Post-installed Rebars in Concrete |
|---|---|
| Author | Kai-Chung Teng, Chiang-Lung Chuang, Yiching Lin, Guo-Ruei Jiang |
| Keywords | quality of planting bars, nondestructive evaluation, stress waves, impact-echo |
| Abstract | This 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. |
| Title | Establishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( I ) :Basic Creep, Drying Creep and Total Creep |
|---|---|
| Author | Ting-Kai Liu, Jenn-Chuan Chern |
| Keywords | Concrete, Long-term Deformation, Creep, Shrinkage, Database |
| Abstract | At 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. |
| Title | Establishment of B4-TW Prediction Model for Concrete Deformation in Taiwan ( II ) : Drying Shrinkage, Autogenous Shrinkage and Total Shrinkage |
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| Author | Wei-Yi Chin, Jenn-Chuan Chern |
| Keywords | concrete, long-term deformation, shrinkage, blast-furnace slag cement, fly ash, dataset |
| Abstract | At 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. |
| Title | Experimental Study of Reinforced Concrete Frame Filled with Low Masonry Window Spandrel |
|---|---|
| Author | Shuenn-Yih Chang, Ping-Chi Wu, Tsui-Huang Wu |
| Keywords | Reinforced Concrete Building, Low Masonry Window Spandrel, Seismic Evaluation, Pushover Analysis |
| Abstract | In 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. |
| 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。 |
| Title | Improving Seismic Performance of Hollow Steel Reinforced Concrete Members with Inclined Bars |
|---|---|
| Author | Hsieh-Lung Hsu, Ming-Te Hong |
| Keywords | steel reinforced concrete, flexural-torsional behavior, inclined bars |
| Abstract | This 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。 |
| Title | The Effect of Different Transverse Reinforcement Schemes on the Confinement of Encased Concrete-Filled Box Columns |
|---|---|
| Author | Cheng-Cheng Chen, Pin-Da Wu, Jia-Xi Zhou |
| Keywords | Encased Concrete-Filled Steel Box Columns, steel reinforced concrete column, SRC column, encased box column, concrete filled box column. |
| Abstract | The 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。 |
| Title | Study on Short-Stroke Damper Assembled in Tuned Mass Damper |
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| Author | Yong-An Lai, Fan-Yen Meng, Kuan-Hua Lien, Lap-Loi Chung |
| Keywords | tuned mass damper, short-stroke damper, optimal design, damper stroke |
| Abstract | In 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 |
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| 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。 |
| Title | Simplified Seismic Evaluation Method on Old Buildings |
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| Author | Yu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Yao-Sheng Yang, Chien-Chuang Tseng, Sheng-Hsueh Lin, Chu-Yuan Chang |
| Keywords | seismic evaluation, maximum base shear, in-situ test |
| Abstract | The 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。 |
| Title | Probabilistic assessment of seismic performance and collapse risk for mid-rise buildings |
|---|---|
| Author | Wei-Huan Hsieh, Lyan-Ywan Lu, Fu-PeiHsiao, Yu-Shi Tang, Yin-Nan Huang |
| Keywords | Wei-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 |
| Abstract | Mid-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. |
| Title | Improving Seismic Performance of Hollow Steel Reinforced Concrete Members with Inclined Bars |
|---|---|
| Author | Hsieh-Lung Hsu, Ming-Te Hong |
| Keywords | steel reinforced concrete, flexural-torsional behavior, inclined bars |
| Abstract | This 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. |
| Title | The Effect of Different Transverse Reinforcement Schemes on the Confinement of Encased Concrete-Filled Box Columns |
|---|---|
| Author | Cheng-Cheng Chen, Pin-Da Wu, Jia-Xi Zhou |
| Keywords | Encased Concrete-Filled Steel Box Columns, steel reinforced concrete column, SRC column, encased box column, concrete filled box column. |
| Abstract | The 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. |
| Title | Study on Short-Stroke Damper Assembled in Tuned Mass Damper |
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| Author | Yong-An Lai, Fan-Yen Meng, Kuan-Hua Lien, Lap-Loi Chung |
| Keywords | tuned mass damper, short-stroke damper, optimal design, damper stroke |
| Abstract | In 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. |
| Title | Simplified Seismic Evaluation Method on Old Buildings |
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| Author | Yu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Yao-Sheng Yang, Chien-Chuang Tseng, Sheng-Hsueh Lin, Chu-Yuan Chang |
| Keywords | seismic evaluation, maximum base shear, in-situ test |
| Abstract | The 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. |
| Title | Probabilistic assessment of seismic performance and collapse risk for mid-rise buildings |
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| Author | Wei-Huan Hsieh, Lyan-Ywan Lu, Fu-PeiHsiao, Yu-Shi Tang, Yin-Nan Huang |
| Keywords | Wei-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 |
| Abstract | Mid-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. |