第三十一卷第四期 (期別124) (105年)

作者:

第三十一卷第四期 (期別124) (105年)

標題高強度鋼筋混凝土柱軸力與彎矩強度互制關係電腦程式-NewRC-PM
作者歐昱辰、蔡東均
關鍵字鋼筋混凝土、高強度、柱、軸力與彎矩強度互制關係、New RC、程式
摘要為因應高層鋼筋混凝土建築之強度需求，「台灣新型高強度鋼筋混凝土結構系統(New RC)研發計畫」於是孕育而生，該計畫整合國內產學界之製造與研究能力，致力於發展適用台灣產業環境與設計規範之New RC 結構。該計畫之縱向主筋與橫向鋼筋，分別採用SD690（降伏強度685 MPa）與SD790 之鋼材（降伏強度785 MPa），混凝土抗壓強度一般為70 MPa 以上。為配合台灣NewRC 計畫，本研究發展一套適用NewRC 柱軸力與彎矩強度(PM)互制關係之計算程式：NewRC-PM，並提供免費下載。本文闡述該程式之計算原理，以及與商用PM 互制關係程式之比對驗證。本研究亦蒐集18 組台灣New RC 柱試驗結果，以NewRC-PM 對其進行強度分析，分析結果顯示NewRC-PM 可保守計算所有18 組柱之軸力與彎矩強度。本研究再利用NewRC-PM 進一步分析該18 組柱之最大可能彎矩強度，分析結果顯示混凝土結構設計規範之方法於所有柱皆得不保守之結果；現行橋梁耐震設計規範之方法顯著改善前述不保守之現象，但壓力控制破壞柱仍普遍呈現不保守之預測結果。本研究最終提出最大可能彎矩強度評估方法，與試驗結果比對顯示所提出的方法可提供合理保守之計算結果。
TitleA Computer Program for Axial Load-moment Interaction Diagram for New High-strength Reinforced Concrete Columns- New RC-PM
AuthorYu-Chen Ou, Tung-Chun Tsai
Keywordsreinforced concrete, high strength, columns, axial load-moment interaction diagram, New RC, computer program
AbstractTo address the need for high-rise reinforced concrete buildings in Taiwan, Taiwan New High-Strength Reinforced Concrete (Taiwan New RC) project was initiated. The project integrates the resources of academia and industry of Taiwan to develop the New RC structures for use in Taiwan. The longitudinal and transverse reinforcement used in the project are SD690 (yield strength of 685 MPa) and SD790 (yield strength of 785 MPa), respectively. The concrete compressive strength is typically ≧ 70 MPa. To support the Taiwan New RC project, a computer program, referred to as New RC-PM, was developed in this research to calculate the axial load-moment (PM) interaction diagram for New RC columns as well as for conventional RC columns. The theoretical background and verification of the New RC-PM are presented and discussed in this paper. Moreover, a test database with 18 New RC columns were established. The New RC-PM was used to analyze the PM interaction diagrams of the columns, which were then compared with the test results. The comparison showed that the New RC-PM could conservatively estimate the axial-bending strengths of the columns. The New RC-PM was further used to evaluate the methods for calculating the maximum probable moment strength (Mpr) of the current building and bridge codes. Evaluation results showed that the Mpr calculated by the current building code was unconservative for all the columns. The method of the current bridge code significantly improved the degree of unconservatism of the method of the building code. However, the Mpr was still unconservative for most compression-controlled columns. To address the issue, a new method to calculate the Mpr was proposed in this research. Comparison with the test results showed that the Mpr calculated by the proposed method was reasonably conservative for most of the columns.
標題使用RC 外加構架補強進行結構耐震補強 —以後甲國中德育樓為例
作者林聖學、賴昱志、鍾立來、黃國倫、曾建創、賴濤
關鍵字外加構架補強、耐震補強、側推分析、樓板剪力傳遞
摘要國內在921 大地震後，許多國中、小校舍損壞相當嚴重，但重建相當不經濟且工程亦相當浩大，故多數選擇採取補強方式，然國內目前常見的補強方式（例如：擴柱補強、翼牆補強及剪力牆補強）皆會影響到結構內部的運作，故本研究提出國內目前較少見之外加構架補強方法，該補強方式不影響結構物本身之運作功能，初步先以校舍進行研究探討此補強工法之可行性，未來可望將此方法推展至內部功能不能停止運作之建築物（例如：醫院）。本研究以後甲國中德育樓進行補強之模擬，以樓板將既有建物與外加構架連接，並進行側推分析，最後進行樓板剪力傳遞之檢核，確認樓板能夠完全將地震力由既有構架傳遞至外加構架，確保此方法之合理性，由設計實例確認本研究所提方法確實能夠提升低矮型校舍之耐震能力。
TitleSeismic Retrofit by External Reinforced Concrete Frames – Using School Building of HOU-JIA Junior High School as Example
AuthorSheng-Hsueh Lin, Yu-Chih Lai, Tao Lai, Lap-Loi Chung, Guo-Luen Huang, Chien-Chuang Tseng
Keywordsretrofit by external frames, seismic retrofit, pushover analysis, shear capacity of slab
AbstractIn Chi-Chi earthquake, the school buildings in Taiwan were damaged seriously. Because rebuilding school buildings will be uneconomical and that will be a tremendous amount of work, seismic retrofit methods are usually adopted to raise seismic performance of buildings. The typical retrofit methods of school buildings in Taiwan include RC jacketing, wing wall and shear wall etc. However, those methods above will affect the function of the existing building during the construction. In this paper, retrofit method with adding external frames, seldom seen in Taiwan, is proposed. The advantage of this method is that the function of the existing building will not be affectedduring the construction. We first use a school building to discuss the feasibility of the method. And it is suggested that the method can be used on the buildings whose functioncannot be affected during construction, such as hospitals. We use a school building of HOU-JIA junior high school to apply a retrofit design of this seismic retrofit method using slabs to connect existing building and external frames. After the retrofit design, we do pushover analysis to make sure the seismic capacity of the retrofitted school building is enough. Finally, we check the shear capacities of slabs to make sure they can completely transfer the earthquake load from the existing building to external frames. By the design example, we prove that the retrofit method of RC external frame is fit to the common squat school buildings.
標題大尺寸BCR 鋼管柱的耐震性能
作者陳正誠、林書豪、吳品達
關鍵字冷軋鋼管、鋼結構、鋼管柱、耐震設計
摘要本文針對大尺寸冷軋方形鋼管柱之韌性發展，以5 支全尺寸試體之反復載重試驗探討之。試體包括裂縫敏感試體及局部挫屈敏感試體，此外採用內藏式橫隔板及外橫隔板工法，進行梁與柱之連接。研究結果發現：（1）冷軋過程對鋼管斷面產生可觀的塑性應變，然而控制梁與柱間銲道施工之銲接入熱量，包括斷面直線段在40 KJ/cm 以內、斷面角隅段在30 KJ/cm 以內，可以避免裂縫過早發生；（2）鋼管柱斷面的寬厚比為10.9 時，試體之容許層間位移角可達7%以上，塑性轉角容量可達4.5%以上；（3）鋼管柱斷面的寬厚比為23.9 時，雖然比規範規定之15.6 大很多，但是試體之容許層間位移角仍可達4.2~4.4%，塑性轉角容量亦有2.1~2.2%，大致可符合耐震之需求；（4）規範對鋼管柱寬厚比限制比箱型柱嚴格，但是試驗結果顯示在相同的斷面寬度及柱板厚度下，兩者的韌性行為頗為類似。
TitleSeismic Performance of Large BCR Steel Columns
AuthorCheng-Cheng Chen, Shu-Hao Lin, Pin-Da Wu
Keywordscold formed structural tube, steel structure, steel column, earthquake-resistant structures
AbstractThis study examined the ductility development of large cold-formed square tube columns through cyclic loading test of five full-sized specimens. Specimens included crack-sensitive and local-buckling-sensitive specimens. In addition, specimens using internal diaphragm and external diaphragm were employed to weld the columns to the beams. Based on the test results, the following conclusions can be drawn: (1) The cold-forming process caused considerable plastic strain on the cross sections of the steel columns, however, by controlling the heat input in the welding passes, premature cracks can then be suppressed. (2) For the specimens with a column wall width-to-thickness ratio equals to 10.9, a story drifty ratio capacity no less than 7% and a plastic hinge rotation capacity no lower than 4.5% can be reached. (3) For the specimens with a column wall width-to-thickness ratio of 23.9, which is much larger the code limitation of 15.6, a story drift ratio capacity between 4.2%–4.4% and a plastic hinge rotation capacity between 2.1%–2.2% can be reached; generally, the specimens satisfied the requirements for seismic structures. (4) Although a more restrict with-to-thickness ratio for cold-formed square section than for box column is specified by the code, the ductility of the structural tube and the box column with the same section width and wall thickness is similar.
標題黏性阻尼器應用於二維與三維建築結構 之最佳化設計
作者詹鵬台、鄭至伸、呂良正
關鍵字黏性阻尼器、阻尼器最佳化配置、剪力構架、三維不對稱建築結構
摘要近年來，被動消能裝置已被廣泛的應用於建築結構中，然而在現行的規範當中，如FEMA273/274 僅提供工程師黏性阻尼器等效阻尼比設計之建議，但更有效益的阻尼器最佳化設計卻鮮少被提及。儘管有些阻尼器最佳配置方法已被提出，但這些最佳化方法往往夾帶著繁瑣且複雜的計算，較難以被實際工程界所接受及使用。為克服此一限制，本研究主要是利用較為簡單且同時兼具理想抗震效益的方法以設計黏性阻尼器之最佳化配置。本文提出新的配置方法，用以將阻尼消能向上提升以增進結構物抵抗地震力。本文將不同的阻尼最佳化配置方法應用於剪力構架以及三維不對稱結構中，利用多筆符合設計反應譜的人造地震歷時對這些方法做檢核。最後，以統計工具來探討各種方法應用於不同建築結構之適用性。
TitleOptimal Design of Viscous Dampers for Two and Three-Dimensional Building Structures
AuthorPeng-Tai Chan, Chih-Shen Cheng, Liang-Jenq Leu
KeywordsViscous dampers, optimal placement of dampers, shear type buildings, three-dimensional asymmetric buildings
AbstractNowadays, passive energy dissipation devices are widely used in building structures. Design codes such as FEMA273/274 suggested that the equivalent damping ratio of supplemental viscous dampers be used. However, how to place viscous dampers optimally was not addressed. Several optimal damper placement methods have been proposed to improve the seismic performance of structures but they usually involve complicated procedure and therefore are not suitable for practical applications. The goal of this study is aimed at finding the optimal placement of viscous dampers using proposed simple methods. The proposed methods and other optimal damper placement methods are applied to different shear type buildings and a three-dimensional asymmetric building. Their performance and applicability are compared using statistical methods under a series of spectrum-compatible ground motions.
標題雙向單擺型調諧質量阻尼器之減振效益分析
作者章靖、廖偉汝、連冠華、鍾立來、賴勇安、曾建創
關鍵字調諧質量阻尼器、雙向分析、風力減振、高樓結構
摘要調諧質量阻尼器(Tuned Mass Damper, TMD)已成功應用在許多高樓建築中並有效抑制風力引致之振動。一般TMD 減振效益分析，主要是針對欲調諧的建築物於某振態在加裝TMD 後，分析其減振效果。模態分析雖簡易，但為單向分析，人們所感受到的舒適程度是以雙向之合加速度來判定，因此模態分析需再配合和方根(Square Root of the Sum of the Squares, SRSS)等方式求得約略之最大合加速度。如直接進行雙向動力分析將會比起單向分析更加直接、適當且準確。此外，如TMD 的阻尼器在空間中斜向放置，則阻尼器提供之阻尼力將雙向耦合。因此，本文除了建立出雙向單擺型TMD加裝於剪力屋架上之分析程序外，並針對空間中斜向放置的阻尼器，推導其阻尼力，進行雙方向的減振效益分析。最後，以一高樓案例進行減振效益分析說明，作為工程業界參考之用。縱然TMD 之阻尼器是斜向安裝，只要對稱配置，耦合之阻尼矩陣，亦能去耦而僅為對角矩陣，即雙向之阻尼力可去耦而不相互影響。只要結構雙向之振動週期夠接近，單擺型TMD 即具雙向減振之功能，在1 年回歸期之風力下，合加速度下降至舒適度之要求；在50 年回歸期之風力下，雙向之基底剪力的減幅，滿足規格之要求。此外，TMD 之阻尼器採斜向配置，可有效降低阻尼器衝程之需求。
TitleEffect of Vibration Reduction of Bidirectional Suspension-type Tuned Mass Damper
AuthorJing Jhang, Wei-Ru Liao, Yong-An Lai, Kuan-Hua Lien, Lap-Loi Chung, Chien-Chuang Tseng
KeywordsTuned Mass Damper, bidirectional analysis, wind-induced vibration control, high-rise building
AbstractThe tuned mass damper (TMD) is widely utilized for civil engineering to control wind-induced vibration in high-rise building. In this research, the design and analysis procedures of the bidirectional suspension-type tuned mass damper are proposed and demonstrated. The main structure is simplified as a shear building model to install the suspension-type tuned mass damper for simulation by the dynamic time history analysis. For common pendulum tuned mass damper, the suspension position and viscous damper implement location are located at different floors. Therefore the reaction force and damping force of the tuned mass damper are acting on different degrees of freedom of the main structure. Although the damping force of a damper is acting in both the two horizontal directions because the damper is implemented with an angle to the floor plane, the damping force is independent in the two horizontal directions if the dampers are allocated in symmetric layout. Therefore, the damping matrix can be decoupled. The feasibility of the bidirectional suspension-type tuned mass damper is illustrated by the high-rise building subjected to the design wind force with return periods of 1 year and 50 years, respectively. Following numerical verification, the effects of vibration reduction for the high-rise building subjected to the design wind forces are demonstrated.
標題以微振法量測斜張鋼纜索力之目標頻率選用
作者吳文華、陳建州、王乙任
關鍵字斜張鋼纜、索力、微振法、振態頻率、錨定系統
摘要工程界用於量測斜張鋼纜索力通常以微振法為主，而為提升索力量測的精度，鋼纜振態頻率的精準選用乃是必要條件。基本上鋼纜之各相鄰振態頻率多接近等間距而不難識別，不過卻可能受到橋體頻率、錨定系統偏向束制以及錨定系統局部振動等因素之干擾而產生混淆，特別在鋼纜長度較短時尤為顯著。本文因此針對由鋼纜訊號所可能識別出的頻率，就其種類與來源進行深入分析，從而希望解決鋼纜振態頻率識別實務上的困難以提升後續索力分析之精度。首先對於橋體頻率交叉混雜的問題，建議宜進行廣泛頻率範圍的識別，然後根據較高階鋼纜振態頻率的近似等間距關係，便容易排除橋體振態頻率在低頻範圍的干擾。其次，如鋼纜因錨定系統前端橡膠套環的偏向束制導致各振態都同時存在一對相當接近的頻率時，需特別注意後續分析最好在不同振態都固定選用數值較低或數值較高的一組，如此索力之計算才能具有共同的邊界束制基礎。至於若因鋼纜與錨定子系統相互耦合而使得振態頻率在特定範圍內出現不規則分岔時，則應謹慎篩選出其他明顯不受耦合影響的鋼纜振態頻率，俾能精確評估索力。
TitleSelection of modal frequencies adopted in ambient vibration method for determination of stay cable force
AuthorWen-Hwa Wu, Chien-Chou Chen, Yi-Ren Wang
Keywordsstay cable, cable force, ambient vibration method, modal frequency, anchorage system
AbstractThe ambient vibration method is typically employed in engineering practice to determine the tension of a stay cable and its precision strongly depends on the appropriate selection of cable frequencies. In general, the modal frequencies of a stay cable are close to an arithmetic sequence and these well separated frequency values are not difficult to be identified. From recent measurements on different stay cables by this research group, however, it is found that the identification of cable frequencies is possibly disturbed by the frequencies of bridge deck, the biased constraint of anchorage system, and the coupled interaction for the cable with its anchorage system. This study is consequently aimed to systematically explore these three types of difficulties such that the goal of clarified cable frequency identification and accurate cable force estimation can be attained. For the confusion caused by the frequencies of bridge deck, it is suggested to conduct the cable frequency identification over a wider frequency range and then exclude the interference of the deck frequencies in the lower frequency range based on the equally spaced relationship of cable frequencies conveniently observed in the higher frequency range. Regarding the biased constraint of anchorage system to induce a pair of frequencies for each vibration mode, it is recommended to consistently adopt the higher or lower frequency value in each pair for the computation of cable force established on a basis of common boundary constraints. Finally, the phenomenon that a particularcable frequency within a specific frequency range can irregularly splitinto two is confirmed to result from the coupled interaction between the cable and its anchorage system. Under such circumstances, special attention should be paid to choose the cable frequencies not influenced by this coupling for evaluating the cable tension.