第三十七卷第一期 (期別143) (111年)
| 標題 | 高強度竹節鋼筋之混凝土劈裂握裹性能與拉力伸展長度 |
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| 作者 | 林克強、林垣彥、紀凱甯、莊勝智、王勇智 |
| 關鍵字 | 高強度鋼筋混凝土、伸展長度、鋼筋強度等級修正係數、劈裂指數、握裹應力 |
| 摘要 | 規範ACI 318-19 之竹鋼筋直線受拉伸展長度公式，增加鋼筋強度等級修正 Ψg鋼筋強度等級超過420 MPa 時，對於550 與690 MPa 者，須依規範ACI 318-14 的計算長度分別加長1.15 與1.3 倍。現行規範中鋼筋伸展長度設計公式 是基於混凝土劈裂機制推導而得，混凝土的劈裂機制主要受混凝土與鋼筋接觸 的性質影響，故本文的主要目的在探討鋼筋強度等級修正Ψg存在的合理性。本 研究共進行20 組梁端的鋼筋握裹試驗試體，伸展鋼筋分別採用420、550 與690 MPa 三種強度等級之#10 鋼筋，同時也變化混凝土強度與劈裂指數兩參數。試驗 結果顯示，20 組試體中的15 組試體發生如預期的混凝土劈裂破壞，試體之劈裂 指數甚至達4.93。從試驗握裹應力的分析中也證實，若混凝土強度與劈裂指數 分別採用70 MPa 與2.5 的上限限制時，規範ACI 318-14 計算所得之直線伸展長 度的試驗平均握裹應力比介於1.72 至2.4 之間，可提供充分的安全餘裕，因此， ACI 318-19 之受拉伸展長度公式中，無需額外增加鋼筋強度等級修正增長因子 Ψ。若將混凝土強度與劈裂指數上限條件分別提升至100 MPa 與5.0，可獲得約 10%保守餘裕的準確結果，惟若應用於工程實務，應考量適當的安全係數。 |
| Title | Bond Splitting Performance of Concrete and Development Length in Tension for High-Strength Deformed Bars |
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| Author | Ker-Chun Lin, Yuan-Yan Lin, Kai-Ning Chi, Sheng-Jhih Jhuang, Yung-Chih Wang |
| Keywords | High-strength reinforced concrete, development length, modification factor of steel grade, split index, bond stress |
| Abstract | For ACI 318-19 Code, a modification factor of steel grade of Ψ that is equal to 1.15 or 1.3 for 550 or 690 MPa grade of steel bar exceeding 420 MPa was added to increase straight development length in tension for deformed bar. It is known that the design equation of development length stipulated in the existing ACI 318 Code was obtained based on a mechanism of concrete splitting primarily dominated by contact characteristics between concrete and steel bar. This paper was intended to investigate the rationality of the Ψ included in the design equation of development length. A total of 20 beam-end specimens was carried out to study bond behaviors of concrete splitting with a deformed bar in this research. A #10 bars for three various grades of 420, 550 and 690 MPa was used as developed steel bar per specimen. Concrete strength and split index were study parameters as well. Test results indicated that the anticipated concrete splitting occurred in 15 specimens of all 20 ones even took place in the specimens with the split index of 4.93. Based on analysis overcomes of the test bond stress in this research, it was confirmed that under upper limitations of 70 MPa for the concrete strength and 2.5 for the split index, the average bond stresses of the three various grade bars for ACI 318-14 Code ranged from 1.72 to 2.4. The modification factor of steel grade of Ψ seemed to not be needed in the provisions of straight development length of ACI 318-19 Code. It was certificated as well that raising the limit limitations of 100 MPa for the concrete strength and 5.0 for the split index, good results with around 10% conservative margin could be obtained according to the provisions of straight development length of ACI 318-14 Code. However, a safety factor should be considered for applications of engineering practice. |
| 標題 | 建立臺灣普通及摻料混凝土強度及彈性模數時間成長函數研究 |
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| 作者 | 王映捷、廖文正 |
| 關鍵字 | 飛灰、爐石、強度、彈性模數、時間函數 |
| 摘要 | 混凝土是由粒料、水泥、礦物摻料、水等材料，依配比設計產生之複 合材料；又混凝土結構物之生命週期需考量安全性及長期服務性，其硬固 後體積會受外力作用而變化，如因環境乾燥所產生的收縮、受持續載重產 生潛變等現象，皆會影響結構物之長期行為。混凝土彈性模數受組成材料 等因素影響甚鉅，彈性模數的增長也會直接影響收縮潛變的評估，但因為 各地所使用之組成材料不甚相同，因此有臺灣本土化之預測模型是非常重 要的。目前臺灣已經有本土化之收縮潛變模型，但缺乏混凝土強度及彈性 模數之時間函數。有鑑於彈性模數、強度在工程應用上的重要性，以及近 年來添加飛灰、水淬高爐爐碴粉等摻料混凝土被廣泛使用，因此本研究將 從臺灣混凝土收縮潛變資料庫出發，以7 種不同水灰比之普通混凝土及固 定水膠比為0.42 之6 種飛灰、爐石取代量之摻料混凝土，分別配合3、 7、14、28、56、91、180 天的齡期，進行抗壓及彈性模數試驗，提出普通 混凝土之強度及彈性模數預測式及時間成長函數，再進一步修正摻料混凝 土之相關模型，除了可供修正臺灣本土化收縮潛變模型外，也能提供工程 界預測使用。 |
| Title | Establishment of Time Dependent Functions for Ordinary and Pozzolanic Concrete Compressive Strength and Modulus of Elasticity in Taiwan |
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| Author | Ying-Chieh Wang, Wen-Cheng Liao |
| Keywords | fly ash, slag, strength, elastic modulus, time function |
| Abstract | Concrete is a widely used construction material composed of aggregate, cement, water, mineral admixture in a specific proportion. Not only safety, long-term serviceability is also the main consideration for buildings and infrastructures made of concrete. The volume of concrete changes over time, such as shrinkage and creep, and all the above influence the long-term serviceability. The elastic modulus of concrete, mainly determined by composition of concrete, directly affects shrinkage and creep behaviors of concrete. However, because materials vary from different resources, a localized prediction model is essential to account for characteristics of concrete in Taiwan and this specific prediction model shall involve localized time function of strength and elastic modulus as well. In view of the importance of elastic modulus and strength in practical applications, and in recent years, the addition of fly ash and water-quenched blast furnace slag in concrete has been widely used, so this research also investigates the shrinkage and creep test data from the database. A comprehensive experimental program, including compression and elastic modulus tests for seven different water-to-cement ratios of ordinary concrete and six different fly ash and slag replacement ratios of water-to-binder ratio of 0.42 for 3, 7, 14, 28, 56, 91 and 180 days, were conducted. The prediction models of time function for strength and elastic modulus for ordinary and fly ash/slag concrete in Taiwan are proposed for further modification of shrinkage and creep model and practical applications. |
| 標題 | 淺談二階分析於鋼結構設計之應用 |
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| 作者 | 彭瑞麟、呂良正、陳紹禮、劉耀鵬、陳惠發 |
| 關鍵字 | 臨界載重、直接分析法、假想側向力、初始缺陷、二階分析 |
| 摘要 | 近年來歐美等先進國家的鋼結構設計規範中， 多建置有二階分析（Second-order analysis）或直接分析(Direct analysis method)的相關規定。事實上二階分析即幾何非線性分析，歐盟及大英國協國際組織內家的鋼結構設計規範採用此名詞；美國工程界認為二階分析與二階彎矩兩個名詞易混淆，故在其鋼結設計規範中採用直接分析法取代二階分析。傳統鋼結構設計以各類構件強度為依據進行，是一種間接計的概念。二階分析則是依據整體結構系統強度和穩定進行設計，是一種直接且更為合理的設計方式，因而受到歐美等先進國家鋼結構設計規範採用。二階分析尤其適合用於水平梁及非垂直柱之組合、且造型不規則又兼具美學外觀、有效長度難以確定的鋼構造物的設計。本文針對歐美等先進國家鋼結構設計規範採用的二階分析情形做初步介紹；為方便工程師掌握內容，文中特別將各國鋼結構 設計規範中與二階分析及直接分析法相關的章節做重點節錄。期望經由本文的介紹，能讓國內工程師瞭解先進國家鋼結構設計的發展，未來的設計能與國際同步。 |
| Title | Brief Introduction to Applications of Second-order Analysis in Design of Steel Structures |
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| Author | Jui-Lin Peng, Liang-Jenq Leu, Siu-Lai Chan, Yao-peng Liu, Wai-Fah Chen |
| Keywords | Critical load, Direct analysis method, Notional lateral force, Initial imperfection, Second-order analysis |
| Abstract | In recent years, the steel structural design codes of advanced countries such as Europe and the United States have stipulated the related regulations of “second-order analysis” or “direct analysis method.” In fact, the second-order analysis, widely adopted in the steel structural design codes of the European Union and the Commonwealth of Nations, is the geometric nonlinear analysis. The American engineering community believes that the terms of “the second-order analysis” and “the second-order bending moment” are easily confused, so the “direct analysis method” is used to replace the “second-order analysis” in the steel structural design code. Traditional steel structural design is mostly carried out on the basis of component strength, which is an indirect design concept. The second-order analysis is designed based on the strength and the stability of the overall structural system. It is a direct and more reasonable design method, which is the reason for the adoption of steel structural design codes in advanced countries such as Europe and the United States. The second-order analysis is especially suitable for the design of steel structures that combine nonhorizontal beams and non-vertical columns, have irregular shapes and aesthetic appearances, and is difficult to determine the effective length. This paper makes a preliminary introduction to the second-order analysis of steel structural design codes in advanced countries such as Europe and the United States. In order to make it easier for engineers to grasp the content, the paper especially makes key excerptions from chapters related to the second-order analysis and the direct analysis method in the steel structural design codes of various countries. It is hoped that through the introduction of this paper, domestic engineers can understand the development of steel structural design in advanced countries, and their designs can be synchronized with international designs in the future. |
| 標題 | 預鑄工法大小梁部分剛性接合之設計 |
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| 作者 | 吳子良、黃世建 |
| 關鍵字 | 預鑄工法、部分剛性接合、剪力傳遞 |
| 摘要 | 土木水利學會與台灣混凝土學會於105 年著手修訂「混凝土結構設計規範」[1]之第九章「預鑄混凝土構材」設計規定條文，業經營建署於106年8 月核定公布實施[2]。修訂之規範條文僅作原則性描述，設計人員不易理解；本文，主要就規範之部分剛性接合設計作補充說明，包括規範修訂主要內容說明、預鑄小梁之結構模型建立、部分剛性接合之定義與設計、及鋼筋細則等。特別針對部分剛性接合之預鑄小梁傳遞剪力提出可能破壞之路徑及計算公式，讓設計者參考；最後，並提供計算案例作為說明，讓有志從事預鑄設計工作者得到充份的瞭解。 |
| Title | Design of partial rigid joint of precast girder and beam |
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| Author | Tzu-Liang Wu, Shyh-Jiann Hwang |
| Keywords | precast, partial rigid joint, shear transfer |
| Abstract | In 2016, the Chinese Institute of Civil and Hydraulic Engineering and the Taiwan Concrete Institute began to revise the design provisions of Chapter 9 of the ” Design Code of Concrete Structures [2] “, “Precast concrete Structures”, which were approved and published by the Construction and Planning Agency Ministry of the Interior in August 2017 [3]. The revised provision is only a principle description, which is not easy for designers to understand; this article mainly provides supplementary explanations on partial rigid joint design of the code, including the description of the main content of the revised provisions, the establishment of the structural model of the precast beams, and the definition of partial rigid joint and design, and reinforcement details, etc. In particular, the path and calculation formula for possible failure of the shear force transmitted by the partial rigid join between girder and beam are proposed for the designer’s reference. Finally, a design case is provided as an illustration, so that those interested in precast design can fully understand. |
| 標題 | 挫屈束制斜撐鋼構架近斷層地震反應：一樓柱側位移及柱軸力加載歷時發展 |
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| 作者 | 劉郁芳、周中哲、彭冠儒、陳冠儒 |
| 關鍵字 | 靜態往覆加載，加載歷時，近斷層地震，非線性動力歷時分析，挫屈束制斜撐 |
| 摘要 | 國內多以美國AISC 規範中抗彎矩構架梁柱接頭加載歷時作為鋼構試驗參考依據，並未制訂挫屈束制斜撐構架(BRBF)之載重歷時，但因不同構架加載歷時對於結構的非線性行為無法真實反應，且一樓柱在反應建築物行為上最具代表性，因此提出建立BRBF 的一樓柱軸力變化及側向位移往 覆加載歷時計劃。台灣居住在鄰近活動斷層10 公里內之人口超過860 萬人，受到近斷層地震機率相當高，若參考美國規範標準載重歷時，將無法反應國內近斷層效應帶來的破壞，因此提出一套涵蓋台灣地理特性考量之鋼構造加載歷時乃十分必要。本研究已完成不同週期BRBF 的非線性靜力側推及 非線性動力歷時分析，瞭解BRBF 在地震作用下力學行為，並提出BRBF 之加載歷時建議，期望能作為未來國內鋼結構研究之參考依據。 |
| Title | Lateral displacement and axial force protocols of the first-story steel column in buckling-restrained braced frames under near-fault earthquake motions |
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| Author | Yu-Fang Liu, Chung-Che Chou, Guan-Ru Peng, Kuan-Ju Chen |
| Keywords | static cyclic loading, loading protocol, near-fault earthquakes, nonlinear dynamic analysis, buckling-restrained brace |
| Abstract | Most of the domestic researchers considered the loading protocol for beam to column moment connections in moment resisting frame (MRF), specified by AISC, as the reference for static cyclic test. The loading protocols for buckling restrained braced frame (BRBF) had not been developed yet. The nonlinear behavior of a structure cannot be truly reflected using the loading protocols of different type of structure. Since the first story columns are generally used to represent the seismic behavior of a building, loading protocols for the first story columns in BRBF with varied axial force and lateral drift should be developed. Moreover, the loading protocols suggested by American specifications might omit the effect of near-fault earthquakes which is common in Taiwan. Therefore, the near-fault effect on buildings is necessary to be considered for better developing the loading protocols for BRBF in Taiwan. This research has completed the nonlinear static and nonlinear dynamic analysis of BRBF which is designed with various periods for a better understanding of seismic performances of BRBF and developing loading protocols for the first story columns in BRBF with varied axial force and lateral drift. The developed loading protocols for BRBF is expected to be a beneficial reference to steel structure study in the future. |