第三十二卷第一期 (期別125) (106年)

作者:

第三十二卷第一期 (期別125) (106年)

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