第三十一卷第二期 (期別122) (105年)

作者:

第三十一卷第二期 (期別122) (105年)

標題不同軸力作用下組合繫筋之一體性及 RC 柱之耐震性能
作者李台光、陳正誠
關鍵字組合繫筋、RC 柱、耐震性能
摘要組合繫筋為由兩支一端為180 度彎鉤另一端為直線的J 形鋼筋搭接組合而成。本研究完成4 支大尺寸鋼筋混凝土柱試體之反復側向載重試驗，探討不同軸力比作用下含組合繫筋柱之一體性及耐震性能。研究結果顯示：(1)含組合繫筋試體之韌性，與含兩端皆為180 度彎鉤一體繫筋之試體不相上下；(2)含組合繫筋之柱試體在無軸力作用下，J 形鋼筋直線端未發現有向柱內滑動的現象，顯示兩個J 形鋼筋有效組合成一個兩端為180 度彎鉤之繫筋，維持良好的一體性；(3)不論使用組合繫筋或180 度彎鉤一體繫筋之試體，其韌性表現皆隨著軸力比的增加，而大幅衰減。
TitleThe seismic performance and crosstie unity of reinforced concrete columns using the lap-spliced crosstie under various axial loads
AuthorTai-Kuang Lee, Cheng-Cheng Chen
Keywordslap-spliced crosstie, RC columns, seismic performance
AbstractA lap-spliced crosstie consists of two J-shaped steel bars (rebars) that have a straight end and an end featuring a 180° hook. In this study, a lateral cyclic load test was conducted on four specimens of large-sized reinforced concrete (RC) columns to investigate the seismic resistance capability and crosstie unity of RC columns comprising lap-spliced crossties under various axial loads. The research results are presented as follows: (a) The ductility of the specimens that adopted the lap-spliced crossties was comparable to that of the specimens using crossties featuring a 180° hook on the two ends. (b) Without axial load, the straight end of the J-bars did not slip toward the inside of the column, suggesting that two J-bars were effectively spliced to be a crosstie featuring a 180° hook on its two ends and maintaining good unity. (c) The ductility of RC columns comprising lap-spliced crossties and crossties featuring a 180° hook on the two ends is significantly decayed with increasing axial load ratio.
標題使用擴頭鋼筋之外柱梁柱接合耐震性能
作者林克強、邱建國、紀凱甯
關鍵字梁柱接頭、擴頭鋼筋、錨定長度、交會區剪力
摘要本文共進行十二組RC 外柱梁柱接合試體，探討梁構件主筋應用擴頭鋼筋錨定於交會區之耐震行為研究，所有試體之梁主筋淨間距分別配置2倍與2.2 倍鋼筋直徑，且均滿足強柱弱梁要求。主要研究參數包括梁主筋配置於交會區內之錨定長度，與梁柱交會區剪力需求容量比。試驗結果顯示，當梁主筋淨間距為2.2 倍鋼筋直徑且錨定長度配置充分並相同時，分別採用擴頭鋼筋與傳統標準90 度彎鉤鋼筋錨定於交會區之梁柱接合試體，在反覆載重作用下之受力變形行為相當，證實擴頭鋼筋取代標準90 度彎鉤鋼筋之可行性。由ACI 374.1-05 與本文建議之耐震性能評估結果顯示，當梁主筋使用擴頭鋼筋錨定於交會區至少符合ACI 318-11 規範之發展長度，且擴頭鋼筋淨間距採用2 倍鋼筋直徑之試體，除發生不可預期之梁構件剪力摩擦滑移的試體外，在4%層間變位角之變形評估下，均能符合強度、勁度與能量的接合性能評估準則，且在實際交會區剪力需求容量比小於約1.15 內不受影響。從試體強度之分析結果也顯示，當梁構件擴頭鋼筋之錨定長度配置符合規範ACI 352-02 規定之發展長度時，鋼筋實際發展之平均強度約可達鋼筋標稱降伏強度1.25 倍之耐震設計規定。
TitleSeismic Behavior of Exterior Beam-Column Joints with Headed Bars
AuthorKer-Chun Lin, Chien-Kuo Chiu, Kai-Ning Chi
Keywordsbeam-column joint, headed bar anchorage length, shear of the panel zone
AbstractThis paper presents the seismic behavior of 12exterior RC beam-column joint specimens that headed bars were adoptedas main bars of their beam members and anchored into theirpanel zone. Two types of net spacing of 2 times and 2.2 times diameter of headed bars were used. All specimens meet the requirements of the strong column-weak beamof the ACI 318-11 Code.Other main parameters included the anchorage lengths of headed bars and the shear demand-to-capacity ratioof the panel zone.The results showed that when the net spacing of headed bars used 2.2 times their diameter and anchorage lengthplaced long enough, the seismic performance of specimen that used headed bars was so well as that of using the standard 90-degree hooked bars.It proved an applicability of the headed bar replacing the hooked bar. Based on seismic assessments of ACI 374.1-05 and proposed by this paper, assessed results indicated that specimens with net spacing of 2 times diameter of headed bar were able to meet their assessed criteria of strength, stiffness and dissipating energy at 4% radian of drift ration as long as the anchored length of headed bar satisfied the development length stipulated in ACI 318-11. However, a specimen with an unexpected failure mode of shear friction slide was excluded. Analysis results of specimen strengths presented that if anchored lengths of headed bar exceeded the development length of headed bar required by the ACI 352-02 Code, the developing average stress of the headed bars was able to reach 1.25 times its nominal yield stress of seismic design requirement.
標題擴柱補強校舍耐震能力之初步評估
作者鍾立來、林聖學、楊耀昇、黃世建、蕭輔沛、邱聰智、吳賴雲、賴昱志
關鍵字校舍結構、擴柱補強、初步評估、現地試驗
摘要初步評估為校舍結構耐震能力篩選程序之重要環節，前人已針對未補強之校舍建立了一套初步評估法，可有效縮小校舍結構耐震問題之規模。針對既有校舍進行初步評估時，乃依據校舍座落之震區、校舍之用途及其一樓垂直構件斷面之尺寸，即可估算其結構耐震之容量及需求，並予以評分，再將所有校舍由低至高排列，依序進入詳細評估及補強設計與施工。然而校舍經補強後則尚無一套簡單、快速之初步評估法，本研究乃針對擴柱補強校舍建立一套初步評估法，首先建立擴柱構件在鋼筋混凝土包覆區之單位斷面積側向強度，再以二座試體之試驗結果驗證此初步評估法之合理性與可行性，包含：材料強度、極限基底剪力強度、容許韌性容量、校舍之全部靜載重、基本振動週期及基本耐震性能，由初步評估所得分析結果均屬保守。利用本研究所建立擴柱補強校舍之初步評估方法，可針對既有校舍擴柱補強時進行初步設計及補強量之估算，而擴柱補強後之校舍亦可藉由本研究之初步評估法檢核其合理性。
TitlePreliminary Seismic Evaluation of School Buildings Retrofitted with Reinforced Concrete Jacketing
AuthorLap-Loi Chung, Sheng-Hsueh Lin, Yao-Sheng Yang, Shyh-Jiann Hwang, Fu-Pei Hsiao, Tsung-Chih Chiou, Lai-Yun Wu, Yu-Chih Lai
Keywordsschool building, reinforced concrete jacketing, preliminary evaluation, in-situ test
AbstractPreliminary evaluation is an important screening procedure for the seismic performance of school buildings so that the magnitude of the problem of seismic deficiency of school buildings can be reduced effectively. According to the seismic zone, importance factor and dimension of the vertical members in the first floor, seismic capacity and demand of a school building can be evaluated. Base on the score (capacity to demand ratio), the priority of the school building to enter into the stage of detailed evaluation is determined. However, a simple and quick evaluation method for the school buildings after retrofit has not been proposed yet. In this paper, a preliminary evaluation method is developed for the school buildings retrofitted with reinforced concrete jacketing. First of all, lateral strength of the reinforced concrete jacketing region per unit cross sectional area is established. Experimental results of two structures are adopted to investigate the feasibility of the proposed method including material strength, ultimate base shear strength, allowable ductility ratio, weight of building, fundamental vibration period and basic seismic performance. After comparison, the preliminary seismic evaluation for school buildings retrofitted with reinforced concrete jacketing proposed in this paper is effective and conservative. Before retrofit design, the amount of retrofit can be estimated by this method. After retrofit design, the rationality of the design can be confirmed by this method.
標題玻璃纖維包覆螺紋管圍束無箍筋之鋼筋混凝土圓柱發展與耐震試驗
作者周中哲、吳愷毅、李中生
關鍵字玻璃纖維複合材料(GFRP)、螺紋管、圍束鋼筋混凝土圓柱、耐震試驗
摘要本研究研發鋼筋混凝土圓柱受玻璃纖維包覆螺紋管（FRP-Wrapped Spiral Corrugated Tube, FWSCT）圍束下的反覆側力耐震行為，本計畫總共製作三座試體，包含一座僅螺紋管圍束的鋼筋混凝土圓柱FWSCT-0，以及兩座分別包覆5 層及8 層玻璃纖維複合材料(GFRP)管的鋼筋混凝土圓柱FWSCT-5 與FWSCT-8，各柱體內皆無橫向箍筋，僅有軸向主筋。試驗使用多軸向材料試驗系統（MATS）進行固定軸力下的雙曲率反覆載重試驗，量測試體的遲滯迴圈、消散能量，以及斷面曲率的分佈情況。試體FWSCT-0在層間側位移角超過1%時發生剪力破壞，試體FWSCT-5(在0.2 倍柱軸力強度作用下)與試體FWSCT-8(在0.6 倍柱軸力強度作用下)分別在層間側位移角6%與8%時發生軸向鋼筋斷裂的撓曲破壞，韌性達到8 與10.7，遠大於傳統鋼筋混凝土圍束圓柱試體於高軸力下之韌性3.7，證明所研發的玻璃纖維包覆螺紋管能有效取代橫向箍筋，提供混凝土柱更佳的圍束、韌性及抗剪能力。研究亦發現此新型的圓柱塑鉸長度發展於柱體兩端管與基礎空隙處以及縱向主筋降伏應變延伸至基礎，並未發展至受玻璃纖維管包覆的柱體內部，藉由試驗觀察到的塑鉸長度進行彎矩曲率分析能準確描述試驗行為及破壞發生時之側向位移量。
TitleDevelopment and Cyclic Tests of Circular RC Columns Confined with a GFRP-Wrapped Spiral Corrugated Tube
AuthorChung-Che Chou, Kai-Yi Wu, Chung-Sheng Lee
KeywordsGlass Fiber Reinforced Polymer (GFRP), Spiral Corrugated Tube, Confined Reinforced Concrete Column, Seismic Tests
AbstractThis paper presents the cyclic behavior of novel circular reinforced concrete columns confined with a FRP-Wrapped Spiral Corrugated Tube (FWSCT). In order to analyze the behavior of FWSCT concrete columns in axial and lateral loads, a load-displacement analysis program was also developed by the authors. Three specimens that had no transverse hoops were constructed and tested under small and large axial loads to investigate their seismic performances. Specimen FWSCT-0 was confined with only a spiral corrugated tube without Glass Fiber Reinforced Polymer (GFRP); Specimens FWSCT-5 and FWSCT-8that were made in Taiwan were confined with 5 and 8 layers of GFRP, respectively. Test results showed that Specimen FWSCT-0 experienced shear failure, while Specimens FWSCT-5 and FWSCT-8 exhibited rupture of longitudinal steel bars at story drifts of 6% and 8%, respectively. It was also found that the plastic hinge of the new column was developed on both ends of the column gap and extended into the footing. The analytical program reasonably predicts test results by using the observed plastic hinge length.
標題新建含挫屈束制支撐之實尺寸兩層樓鋼筋混凝土構架耐震設計、試驗與分析研究： 一、試體設計與耐震試驗
作者楊巽閎、黃潔倫、吳安傑、李昭賢、蔡青宜、王孔君、蔡克銓
關鍵字鋼筋混凝土結構、挫屈束制支撐、預埋鐵件、擬動態試驗、耐震設計、軟化壓拉桿模型
摘要挫屈束制支撐（buckling-restrained brace, BRB）能提升構架的勁度、強度與韌性，且以不發生挫屈為特點，已廣泛運用在鋼結構建築中。BRB雖已應用在一些鋼筋混凝土（reinforced concrete, RC）構架補強中，但應用在新建RC 構架中卻不常見，主要因為鋼與RC 構件之連接介面設計與施工較困難與複雜。本研究提出以預埋工字型鐵件作為RC 構件與BRB 連接介面之耐震設計與分析方法，藉由鐵件傳遞BRB 至RC 梁柱構件表面之正向力與剪力，確保BRB 及RC 構架均能發揮原設計性能。本研究以一座雙層實尺寸總高7.41m、寬5m 含BRB 之RC 構架（BRB-RCF）試驗與分析，分為兩篇探討預埋鐵件之設計和施工方法、構架整體耐震性能及接合板與RC 梁柱構件之受力行為。構架試體採用A36 鋼材BRB 與之字形配置，接合板設計考慮BRB 軸力與梁柱開合效應，梁柱構件設計滿足ACI 318-14耐震設計規範，並於國家地震工程研究中心進行四次擬動態與反覆載重試驗至試體破壞為止。本研究亦對雙層BRB-RCF 試體建立PISA3D 模型分析，挑選擬動態試驗之地震歷時並預測試驗反應。分析預測與試驗比對結果顯示，BRB-RCF 於小震時之反應可以PISA3D 預測模型合理預測。試驗結束後，本研究進一步利用試驗反應校正PISA3D 分析模型，以達到更準確之模擬結果；試驗所得及模擬結果在下篇中做更詳細說明。
TitleSeismic Design, Tests and Analysis of a Full-scale Two-story Reinforced Concrete Frame with Buckling-restrained Braces – Part I: Specimen Design and Seismic Tests
AuthorHsun-Horng Yang, Jie-Luen Huang, An-Chien Wu, Chao-Hsien Li, Ching-Yi Tsai, Kung-Juin Wang, Keh-Chyuan Tsai
Keywordsreinforced concrete frame, buckling-restrained brace, steel embedment, hybrid test, seismic design, softened strut-and-tie model
AbstractBuckling-restrained braces (BRBs) have been widely used nowadays in steel structures as it can provide high stiffness, strength and ductility without compression buckling. Researches on using BRBs for seismic retrofit of existing reinforced concrete (RC) buildings have been reported. It is found the construction of BRB and RC member interfaces are often difficult, mostly due to the tensile and shear strengths of post-installed anchors in concrete are limited. As a result, the size and effectiveness of the BRBs are restricted. Nonetheless, researches on applying BRBs for new RC constructions are rather limited. This research investigates the seismic design and analysis methods of using the proposed I-shape steel embedment as the interface for the BRB and RC members. Steel embedment is designed to transfer the BRB normal and shear forces in order to secure the seismic performance of the RC buildings. In this study, a full-scale two-story RC frame with BRBs (BRB-RCF) is tested using hybrid and cyclic loading test procedures. The BRBs are arranged in zigzag configuration. The design of gussets incorporates the BRB axial and RC frame actions, while the beam and column members comply with ACI 318-14 seismic design provisions. The results are divided into two papers to discuss the design and construction methods of the steel embedment, seismic performance of the BRB-RCF, and seismic responses of the BRBs, gussets and RC members. A typical PISA3D numerical model of the BRB-RCF was constructed to predict the test responses and select the earthquake ground motions for hybrid tests. Analytical results indicate that the seismic responses of the BRB-RCF can be satisfactorily predicted only under the small earthquake. After all tests, a calibrated PISA3D numerical model is validated. It is illustrated with details in the Part II paper that the experimental responses of the BRB-RCF can be accurately simulated using the proposed procedures.
標題新建含挫屈束制支撐之實尺寸兩層樓鋼筋混凝土構架耐震設計、試驗與分析研究： 二、試驗結果與模擬分析
作者楊巽閎、黃潔倫、吳安傑、李昭賢、蔡青宜、王孔君、蔡克銓
關鍵字鋼筋混凝土結構、挫屈束制支撐、預埋鐵件、擬動態試驗、接合板挫屈、非線性分析
摘要在第一篇中已詳細介紹雙層含挫屈束制支撐（buckling-restrained brace, BRB）鋼筋混凝土（reinforced concrete, RC）構架（BBR-RCF）之設計與預測分析，本篇則討論BRB-RCF 之試驗觀察、試驗與模擬分析結果。試驗結果顯示，在50/50 級地震作用下，一樓及二樓BRB最大水平剪力分別占整體構架水平剪力之52%與71%；在10/50 與2/50 級地震時，則分別為60%與70%，證實BRB 能提供整體構架良好側向勁度與強度。四次擬動態試驗中，各層遲滯能量消散比例介於60%至94%，證實BRB 能消散大部份的地震能量。反覆載重試驗完成2.75%層間側位移（inter-story drift ratio, IDR）的加載時，一樓與二樓BRB 之總累積塑性變形量已分別超過476 與680。當反覆載重試驗進行至試體IDR 達3.5%時，側向強度仍未下降，且維持穩定的遲滯消能行為。進行至IDR 為4.5%時，一樓上端接合板才發生挫屈，但亦導致一樓BRB 圍束鋼管發生整體撓曲挫屈。當一樓頂接合板之有效長度因子Kcr 採2.0 計算時，需求與強度比（demand-to-capacity ratio, DCR）將達1.05，且一樓BRB圍束鋼管之設計DCR已高達0.95，顯示接合板挫屈後牽動BRB 圍束鋼管發生整體撓曲挫屈，試驗與此分析結果相符。試驗結果顯示，本研究所提之鐵件施工與設計方法可行，在試驗程中保持彈性，並證實所採RC 構件不連續區域之設計方法能避免破壞發生，可供工程應用參考。由於預測模型高估10/50 及2/50 地震等級下之反應，本篇詳述利用試驗反應進一步校正PISA3D分析模型之方法，模擬結果大幅提高分析模擬於2/50 等級地震下之準確度。
TitleSeismic Design, Tests and Analysis of a Full-scale Two-story Reinforced Concrete Frame with Buckling-restrained Braces – Part II: Test Results and Response Analysis
AuthorHsun-Horng Yang, Jie-Luen Huang, An-Chien Wu, Chao-Hsien Li, Ching-Yi Tsai, Kung-Juin Wang, Keh-Chyuan Tsai
Keywordsreinforced concrete frame, buckling-restrained brace, steel embedment, hybrid test, gusset buckling, nonlinear analysis
AbstractSeismic design and analytical response predictions of the full-scaled two-story BRB-RCF are introduced in the Part I paper. This Part II paper discusses the experimental observations, test results and analytical simulations using a refined PISA3D model. In the 50/50 earthquake, the ratios of peak BRB and BRB-RCF shear are 52% and 71% for the first and second stories, respectively. Similar ratios can be obtained if a factor 0.7 is applied on the gross moment of inertia for RC members in the ETABS elastic model. In the 10/50 and 2/50 events, the ratios become about 60% and 70% for the first and second stories, respectively. These indicate that BRBs can provide a high lateral stiffness and strength. The hysteresis energy dissipated ratios in the four hybrid tests are ranging from 60% to 94% for the two stories, confirming that BRBs can effectively dissipate seismic input energy. When the 2.75% inter-story drift ratio (IDR) cycles were completed during the cyclic loading test, the cumulative plastic deformations were more than 476 and 680 for the first- and second-story BRBs, respectively. When both two stories reached an IDR of 3.5%, the frame’s lateral force versus deformation response was still very stable. Up to the first IDR=4.5% loading cycle, the first story top gusset buckled, caused the subsequent flexural buckling of the first story BRB to occur. This is consistent with the predicted results as this gusset’s demand-to-capacity ratio DCR is 1.05 for the buckling limit state when the effective length factor Kcr=2.0 is considered. Nonetheless, the buckled BRB have a DCR=0.95 in the steel casing. No failure of the steel embedment is observed in the tests. Test results confirm that the ACI provisions and the simplified softened strut-and-tie model can be effectively applied to prevent the RC discontinuity region failure. This study demonstrates that the proposed design and construction methods for the steel embedment are effective and practical for the real applications. The response analysis of the refined PISA3D model calibrated from using the test results is conducted to demonstrate the accuracy enhancement compared to the typical model.