第二十九卷第二期 (期別114) (103年)
| 標題 | 鋼筋混凝土偏心梁柱接頭之抗剪強度設計 |
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| 作者 | 黃世建、Erwin Lim、翁樸文、李宏仁 |
| 關鍵字 | 梁柱接頭、有效面積、抗剪有效寬度、偏心梁柱接頭 |
| 摘要 | 現行之ACI 318-11 規範[1]參考了ACI-ASCE 352 規範委員會[2]之多項建議，定義梁柱接頭之剪力計算強度為平均剪應力容量與接頭有效面積之乘積。但多年之使用經驗顯示，ACI 318-11 規範[1]對偏心梁柱接頭抗剪有效寬度之規定過於嚴苛。本研究探討四種接頭有效寬度的計算方式，其中包含ACI 318-11 [1]、ACI 352R-02 [2]、AIJ Guidelines [3]與 NZS 3101 [4, 5]等規範。本文除了以資料庫實驗結果比較各規範有效寬度之差異，更進一步地提出接頭有效寬度之公式。本文提出的接頭有效寬度可反映各種矩形梁柱接頭之幾何尺寸變化差異，並可合理預測資料庫之偏心及同心梁柱接頭的剪力強度。本文所建議之接頭有效寬度，除可供接頭剪力強度設計之經驗公式使用外，其亦具有力學意義，而能應用在接頭剪力強度預測之解析模型中。此外，依據現有之同心外部(T 形)梁柱接頭實驗結果，本文也重新強調工程師在接頭區內需將梁主筋彎鉤延伸至柱核心區遠端錨定的重要性。 |
| Title | Design of Shear Strength for Eccentric Beam-Column Joints |
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| Author | Shyh-Jiann Hwang, Erwin Lim, Pu-Wen Weng, Hung-Jen Lee |
| Keywords | beam-column joint, effective joint area, effective joint width, eccentric beam-column joint |
| Abstract | The current ACI 318-11 building code, which adopts many recommendations from ACI-ASCE Committee 352, defines the nominal joint shear strength of a beam-column connection as the product of the average shear stress capacity and the effective joint area. Past experience did indicate that the ACI 318-11 provisions on the effective joint width of the eccentric beam-column joints are too strict. This study critically evaluates four sets of effective joint width provisions, available in ACI 318-11, ACI 352R-02, AIJ Guidelines, and NZS 3101, as well as the companion provisions for average shear stress capacity. Comparisons and experimental verifications have been made among the code provisions; and more general expressions of effective joint width are proposed for design. The proposed effective joint width considers various sizes of rectangular joints and gives consistent strength estimations for both concentric and eccentric beam-column connections. Since the proposed effective joint width possesses the physical meaning of concrete crushing, it can be used both in the ACI 318-11 design method and the associated analytical procedures. Furthermore, based on available research data for concentric exterior (T-shaped) beam-column connection specimens, this study re-emphasizes engineers to extend beam longitudinal bars to the far face of the confined column core. |
| 標題 | 口湖國小含磚翼牆校舍之耐震能力初步評估與現地試驗驗證 |
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| 作者 | 楊耀昇、鍾立來、邱聰智、蕭輔沛、江文卿、黃世建、吳賴雲 |
| 關鍵字 | 校舍結構、磚翼牆、耐震性能、初步評估、現地試驗 |
| 摘要 | 臺灣校舍之數量龐大，且耐震能力堪虞，需以經濟、有效之方法篩選出耐震有疑慮之校舍，再以補強或重建之方式全面提升校舍之耐震能力。初步評估為一簡單且客觀之篩選方法，可快速估算出校舍結構之耐震容量與耐震需求。國家地震工程研究中心曾執行四次校舍現地試驗，針對梁柱構架試體進行初步評估並與試驗結果比較，初步評估之合理性已獲得驗證。臺灣校舍在縱沿走廊方向普遍有磚翼牆存在，為探討初步評估法對此種含磚翼牆校舍之保守性，本文以口湖國小現地試驗中一座含磚翼牆校舍試體為標的，該校舍之RC 柱斷面積與磚翼牆斷面積相當，從其材料強度、單位面積重量、極限基底剪力強度、基本振動週期、容許韌性容量及基本耐震性能，比較初步評估之估算值與現地試驗之實測或實算值。經檢核後，初步評估在材料強度、極限基底剪力強度及容許韌性容量之估算上，均為保守；在單位面積重量之估算上，該試體之磚牆量較高，故初步評估之估算值略為低估；在基本振動週期之計算，該校舍之磚翼牆提供強度和已達柱子側向強度和之30%，故採用規範所定各類建築物中週期最短之經驗公式計算，估算出之基本振動週期仍略高於實算值；在基本耐震性能方面，初步評估雖在校舍結構之全部靜載重低估，但因極限基底剪力與容許韌性容量低估，其基本耐震性能為現地試驗之51.7%，顯示此初步評估法為保守且具可行性。 |
| Title | Verification of seismic preliminary evaluation of school building with brick walls by in-situ test at kou-hu school |
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| Author | Yao-Sheng Yang, Lap-Loi Chung, Tsung-Chih Chiou, Fu-Pei Hsiao, Wen-Ching Jaung, Shyh-Jiann Hwang, Lai-Yun Wu |
| Keywords | school building, brick walls, preliminary evaluation, in-situ experiments |
| Abstract | Existing school buildings in Taiwan are numerous and vulnerable under earthquakes so that economical and effective methods to screen those buildings with insufficient seismic capacity is necessary. Preliminary evaluation is a simple and objective screening stage in which seismic capacity and demand of an existing school building can be computed easily. The National Center for Research on Earthquake Engineering has conducted in-situ experiments in four schools. Preliminary evaluation of school buildings without brick walls has been validated. In Taiwan, school building with brick wing walls along the corridor direction is very common. In this paper, in-situ experimental results of a school building with brick walls at Kou-Hu Elementary School are adopted to verify the preliminary evaluation method. In this building, the cross-sectional area of brick walls is as much as that of columns. The material strengths, weight per unit floor area, ultimate base shear strength, fundamental vibration period, allowable ductility capacity and fundamental seismic performance from preliminary evaluation are compared with those from in-situ tests. From the comparison, preliminary evaluation is conservative in material strengths, ultimate base shear strength and allowable ductility capacity. Because of brick walls, preliminary evaluation underestimates the weight per unit floor area. Since the strength contributed by brick walls exceeds 30% of that contributed by columns, empirical formula with shortest vibration period stated in the seismic codes is adopted in the preliminary evaluation. However, it is still longer than the vibration period extracted from the in-situ results. As a whole, the fundamental seismic performance from preliminary evaluation is just 51.7% of that from in-situ experiment. Therefore, the proposed preliminary evaluation method is conservative and feasible. |
| 標題 | 低強度鋼筋混凝土柱之耐震補強實驗研究 |
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| 作者 | 張順益、陳亭偉、林忠毅、羅閎譯、陳玉強 |
| 關鍵字 | 低強度鋼筋混凝土柱、耐震補強、擴柱、翼牆、反覆載重試驗 |
| 摘要 | 本文針對低強度鋼筋混凝土柱進行耐震補強實驗研究，試驗結果顯示不管是擴柱或是增設翼牆補強都能有效提高側向抗剪強度，其中擴柱補強的韌性比及遲滯消能能力都遠優於增設翼牆補強。這是因為經擴柱補強後，其抗彎及抗剪的能力都能有效的提升，且試體係由撓曲破壞所控制，因而能提高韌性強度。另一方面，增設翼牆補強後，雖然抗剪能力得到有效的提升，但原柱柱體與翼牆卻分別發生彼此獨立的剪力破壞，且側向強度在位移相對較小時即達最大值。在側向強度達最大值之後，試體之強度及勁度隨即出現快速衰減，因而使韌性強度不佳，是以遲滯迴圈出現典型的剪力破壞模式以及嚴重的遲滯迴圈收縮現象。擴柱補強係將原柱柱體完全封閉式的包圍在中央核心，因此即使不考慮原柱的貢獻，外圍的補強體將如同一中空柱能獨立的抗彎抗剪，如此一來，不管原柱柱體與補強體是否能完全有效連結，擴柱補強都能穩定的提高耐震能力。雖然翼牆補強是希望透過植筋使新舊混凝土完全結合在一起共同抵抗外力，但因混凝土強度偏低植筋並無法達此目標，以致於原柱柱體與翼牆分別發生彼此獨立的剪力破壞，即使如此，翼牆補強由於優異的力學機制仍能達到有效提高抗剪能力的目的。 |
| Title | Experimental Study of Seismic Retrofitting of Low Strength Reinforced Concrete Columns |
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| Author | Shuenn-Yih Chang, Ting-Wei Chen, Chung-Yi Lin, Hung-Yi Lo, Ngoc-Cuong Tran |
| Keywords | low strength, reinforced concrete column, seismic retrofit, column jacketing, wing wall, cyclic loading test |
| Abstract | In this paper, the low strength RC columns were seismically retrofitted and cyclically tested. Test results reveal that either the column jacketing or wing walls can effectively increase the lateral shear strength. In addition, The RC jacketing can have a better improvement in capability of energy dissipation and in ductility when compared to installing wing walls. RC jacketing not only increases moment and shear capacity but also results in a flexural failure mode. Thus, the ductility increases. On the other hand, although RC wing walls can increase shear capacity, the original column and the wing walls cannot be integrated together and experience shear failure independently. After yielding the maximum lateral strength, the stiffness and strength are rapidly degraded and thus the specimen results in poor ductility. Apparently, the hysteretic loops can be classified as a typical failure mode, where stiffness degrading and strength degrading in addition to pinching are found. The jacket around the original column can be considered as a hollow column and thus it can resist both flexural moment and shear force. Consequently, RC jacketing can effectively increase the resistance to moment and shear whether the connections between the original column and new jacket are good or not. It is anticipated that the post-installed anchors can integrate the new and existing concrete together to resist seismic force for RC wing walls. However, this goal cannot be achieved due to the low strength concrete. As a result, an independent shear failure is found for the original column and the two wing walls. Even so, it is evident that RC wing walls can still enhance the shear capacity due to the very good mechanism. |
| 標題 | 以數值分析評估單棟RC建築物震後損失 |
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| 作者 | 薛 強、蕭輔沛、邱天宏、邱聰智、張權、周德光、翁健煌、葉勇凱、陳正忠、鍾立來 |
| 關鍵字 | 耐震性能、非線性分析、損失評估、修復費用 |
| 摘要 | 本文建立以數值分析評估RC 建築物震後損失之方法，經由耐震性能評估法與非線性分析求取結構構件於震後之行為，並判定其對應之破壞等級，再應用基於震後破壞程度之損失評估方法推估對應之損失比，即可了解修復費用以及是否可以修復補強還是需要拆除重建。最後以一老舊建築物以及一近期設計之建物為例，經由非線性靜力側推分析建立性能點譜位移與最大樓層損失比之關係曲線。藉由本文研提之方法有助於建築物生命週期維護管理之決策，亦為下一代耐震性能設計以控制震後損失後果與風險為標的提供方法。 |
| Title | Post-earthquake financial loss estimation of an individual RC building through numerical anlaysis |
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| Author | Qiang Xue, Fu-Pei Hsiao, Tian-Hung Chiu, Tsung-Chih Chiou, Chyuan Jhang, Te-Kuang Chow, Jian-Huang Weng, Yeong-Kae Yeh, Cheng-Chung Chen, Lap-Loi Chung |
| Keywords | seismic performance, nonlinear analysis, loss estimation, repair cost |
| Abstract | This paper establishes a numerical method to estimate post-earthquake financial loss of an individual RC building. Through nonlinear analysis and seismic performance evaluation, structural behavior subjected to an earthquake excitation can be estimated. Corresponding damage degrees can be determined accordingly. Financial loss in terms of the repair to replacement cost ratio of the most severely damaged storey is estimated based on the post-earthquake damage degree. As a result, the repair cost is obtained and it is clear whether the building needs rehabilitation or rebuilt after demolition. Finally, we take an old building and a lately designed building as examples to establish correlation curves between the spectral displacement and the repair to replacement cost ratio of the most severely damaged storey through nonlinear static pushover analyses. The method proposed in this paper helps decision-making of lifecycle maintenance and management of existing buildings. It also provides a method to control post-earthquake damage consequence and risk for the next-generation of performance-based seismic design. |
| 標題 | 交錨型雙核心自復位斜撐發展驗證耐震試驗及有限元素分析 |
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| 作者 | 周中哲、鍾秉庭 |
| 關鍵字 | 交錨型雙核心自復位斜撐、高拉力鋼鉸線、試驗、有限元素分析 |
| 摘要 | 預力型自復位斜撐(SCB)是利用斜撐中的拉力構件束制斜撐中的鋼受壓構件，並在斜撐受軸拉與受軸壓下提供自復位能力，即在大變形下有回到零殘餘變形的能力。在拉力構件相同應變下，前一代雙核心自復位斜撐變形量可達單核心自復位斜撐變形量的兩倍(或是在相同斜撐變形量下，拉力構件的拉應變減少一半)，有效降低拉力構件彈性應變需求，為進一步地減少拉力構件所需施拉預力數量，本研究發展交錨型雙核心自復位斜撐，改變前一代雙核心自復位斜撐之兩組拉力構件及三組鋼受壓構件的配置，減少外圍斷面尺寸，且拉力構件所需施拉預力數量僅為前一代雙核心自復位斜撐之拉力構件所需施拉預力數量的一半。本研究除了說明新發展之交錨型雙核心自復位斜撐(Cross-Anchored Dual-Core Self-Centering Brace)力學理論外，並設計及試驗一組7950 mm 長的交錨型雙核心自復位斜撐，拉力構件均使用D16(直徑 15.24 mm)高拉力鋼鉸線。在歷經3 次AISC(2010)反覆載重試驗與60 圈疲勞載重試驗下無破壞，顯示交錨型雙核心自復位斜撐之傳力機制與理論預測相符，而且有穩定的自復位及能量消散的能力，耐震性能符合AISC(2010)規範針對挫屈束制斜撐要求在最小層間側位移角2%前不破壞原則，斜撐更可達到層間側位移角2.5%而不破壞，最大斜撐軸力可達約1700 kN。本研究並利用非線性有限元素分析軟體ABAQUS 分析交錨型雙核心自復位斜撐試驗行為，有限元素分析與試驗結果及理論預測相符，進一步地驗證交錨型雙核心自復位斜撐的耐震消能行為。 |
| Title | Development and Validation of a Cross-Anchored Dual-Core Self-Centering Brace: Seismic Test and Finite Element Analysis |
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| Author | Chung-Che Chou, Ping-Ting Chung |
| Keywords | Cross-Anchored Dual-Core Self-centering Brace (SCB), High-Strength Steel Tendons, Cyclic Test, Finite Element Analysis |
| Abstract | The steel dual-core self-centering brace (SCB) is a novel structural member that provides both energy dissipation and re-centering properties to structures under earthquakes. The axial deformation capacity of the brace is doubled by using two inner cores and one outer box and by serial axial deformations of two sets of parallel tensioning elements. A new cross-anchored dual-core SCB is proposed to reduce half the number of tensioning elements needed for applying the initial post-tensioning work compared to the original dual-core SCB, to investigate the potential use of high-strength steel tendons as tensioning elements, and to examinethe effects of number of cycles on the brace behavior, energy dissipation, and durability of the steel tendon-anchorage system.The mechanics and cyclic behavior of the new brace are first explained; a 7950-mm long cross-anchored dual-core SCB is tested six times. The cross-anchored dual-core SCB exhibits excellent self-centering property up to a lateral drift of 2.5% with a maximum axial load of 1700 kn. No damage of steel tendons, anchors or bracing members is found after three cyclic loading tests by AISC (2010) seismic provisions and 60 low-cycle fatigue tests. Finite element analysis is conducted to furtherverify the hysteretic responses and mechanics of the proposed cross-anchored dual-core SCB in the cyclic tests. |
| 標題 | 臺北市社子大橋之分析與設計 |
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| 作者 | 張英發、黃昭勝、游明益、林曜滄、張萩薇、宋裕祺 |
| 關鍵字 | 斜張橋、斜塔柱、旋轉工法、自錨式、最佳化 |
| 摘要 | 臺北市社子大橋係採用一傾斜橋塔搭配二跨不對稱主梁跨徑(180m+70m)之鋼斜張橋。本橋主梁長短跨比高達2.57，除於短跨處設置壓重混凝土外，並採用造型新穎的傾斜橋塔，配合最佳化鋼索預力的施加，克服上部結構主梁及橋面板等靜載重因長短跨徑差異而產生不平衡力的影響，達到符合力與美的設計目標。本橋配合180m 中跨徑主梁之特性，採用自錨式(self-anchored)鋼索錨定方式，除滿足經濟設計之需求，在耐震設計方面依靜力分析進行設計，並採用動力歷時分析作為耐震性能檢核;在抗風設計方面，除依據橋梁設計規範之相關規定進行設計外，並以斷面模型及全橋模型之風洞試驗檢核相關空氣動力參數及受風反應，驗證本橋的的耐風性能並與設計階段風力作比對，確保本橋梁之耐風穩定。此外，為確保鋼索錨碇鄰近區域構造細節之安全性能，對錨碇區域進行有限元素局部應力分析，以判斷局部應力傳遞是否合宜。本橋在結構分析及設計上，有別於一般橋梁者，具備獨特性與困難度，為一難得之橋梁工程設計經驗，本文所得成果，冀可供為日後相關工程之參考。 |
| Title | THE ANALYSIS AND DESIGN OF SHEZI BRDIGE IN TAIPEI |
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| Author | Eng-Huat Teo, Chao-Sheng Huang, Ming-Yi Yu, Yew-Tsang Lin, Dyi-Wei Chang, Yu-Chi Sung |
| Keywords | Cable-Stayed Bridge, Inclined Pylon, Rotating Method, Self-Anchored, Optimum. |
| Abstract | Being an asymmetric span configuration (180m+70m), the SheZi Bridge in Taipei was designed as an inclined pylon steel cable-stayed bridge.As the asymmetric span configuration has a ratio of main span to side span up to 2.57, the loading of the superstructure generated a huge unbalanced effect to the pylon and the girder. Therefore, the counterweight concrete was designed for unbalanced loading effect, and the inclined pylon and the optimization post-tensioning cable force analysis were used to reduce the unbalanced effects caused by the static load applied and for enhancing the aesthetics design. As the span has a length of 180m, we used a self-anchored cable system for this bridge. Though the static analysis result was used for structural design, the dynamic analysis was also required. For the dynamic analysis of this bridge, both the response spectrum method and the time history method were used. To verify the wind resistance of the bridge and to obtain the aerodynamic parameters, the cross section model and the full model for wind tunnel tests were done to ensure the performance of the bridge’s resistance to wind;and to make a comparison of the wind force during the design stage; and to double check the wind resistant design. In addition, to ensure the safety of the cable anchorage, the finite element analysis was done to verify the stress delivery. This article will take this bridge as an example, carry out the analysis and design of cable-stayed bridge with asymmetric span and inclined pylonhaving unique and difficulty, and provide as a reference for the engineering of related projects. |