鋼筋混凝土結構牆耐震行為研究

Studies on the Seismic Behaviors of Reinforced Concrete Structural Walls

黃昭琳(Chao-Lin Huang)

指導教授 ： 林至聰 ； 李有豐

國立臺北科技大學/工程學院/工程科技研究所/博士(2011年)

https://doi.org/10.6841/NTUT.2011.00543

摘要

本論文以解析及數值分析探討鋼筋混凝土結構牆在側向載重下之耐震行為。在線彈性階段，滿足力學三大基本原則：力平衡、變位諧和、組成律及邊界條件等推導力-位移關係曲線。在塑性階段，以單自由度系統模擬鋼筋混凝土結構牆，以推導其非線性撓曲行為。此外，另以等值寬柱模擬結構牆並應用於靜力側推分析。藉由上述理論分析及側推分析力-位移關係曲線可預測結構牆試驗結果及初步耐震評估。
鋼筋混凝土結構牆雖有很多結構及經濟上之優點，但仍有一些缺點，其主要缺點為側向勁度太大，造成應力集中現象，因而導致結構牆易發生脆性斜向剪力裂縫及邊構材壓碎破壞，是以控制破壞為性能基準設計重要課題之一。為達此目的，結構物須能有效的消散地震能量並防止脆性剪力破壞。因此，為改善傳統剪力牆在反覆側向載重下之耐震行為，本論文以最大主拉應力及壓應力軌跡曲線之觀念，提出同心圓及螺旋狀二種新型牆體配筋方式，並在國家地震中心試驗。實驗結果顯示，本文所提改良式配筋相較於傳統剪力牆具有較佳韌性及消散地震能量。這意味較大的[X-型] 脆性剪力裂縫可以避免，而許多微小裂縫則逐漸的均勻分佈於牆體。此外，本改良式結構牆尚可有效控制裂縫發生及伸展，因所提改良式配筋形狀大致垂直於裂縫方向且與最大主拉應力方向大致相同，故能顯現較佳韌性破壞模式。

關鍵字

鋼筋混凝土結構牆 ； 力-位移關係曲線 ； 耐震行為

並列摘要

This thesis combines analytical and numerical approaches to the nonlinear behaviors of reinforced concrete (RC) structural walls under lateral loads, and this study utilizes a bilinear force-displacement relationship. In the elastic regions of RC walls; the equations of equilibrium, constitutive laws, compatibility equations, and boundary conditions are used. In plastic regions, the RC structural wall is modeled as a single degree of freedom (SDOF) spring-mass system to determine the seismic response of RC walls. In addition, an “equivalent wide column” model for RC walls is proposed and applied to perform nonlinear static pushover analysis. The lateral force-displacement relationships obtained by analytical studies and pushover analysis can accurately predict the experimental results in the elastic and inelastic regions. Furthermore, a simple analytical strategy for predicting the seismic behaviors of both single cantilever structural walls and coupled-wall systems is proposed. While the concept of equal displacement for RC structural wall systems subjected to uniform translation based on specified drift limits will be considered. The proposed method is simple, feasible, and applicable to both force-based and displacement-based seismic design approaches, which is a useful and practical tool for the seismic evaluation of existing RC structural wall buildings.
One of the basic requirements in performance-based design is to control the damage in the structural wall buildings when they are subjected to cyclic loading. To achieve this goal, the RC structure should be able to dissipate energy during seismic events, and prevent the brittle shear failure mode. Therefore, based on the concept of principal tensile and compressive stress trajectories, RC structural walls with extra concentric circles or spiral web reinforcements are presented, and tested under cyclic loading at the National Center for Research on Earthquake Engineering. The test results showed that the proposed innovative RC structural walls had greater ductility and higher energy dissipation than those of traditional shear walls. This implies that “X-shaped” bi-diagonal shear cracks can be avoided. Instead, the numbers of minor cracks gradually and uniformly propagate into the wall surface. Moreover, the test results also indicated that the improved RC walls can effectively prevent inclined shear cracks from happening and growing in the walls. This is because the proposed new web reinforcement configurations are nearly perpendicular to the inclined shear cracks and close to the principal tensile stresses trajectories.

並列關鍵字

RC structural wall ； Force-displacement relationships ； Seismic behavior

參考文獻

[1] ACI Committee 318, (2008). “Building Code Requirements for Structural Concrete and Commentary,” (ACI), Michigan, USA.

[2] ATC-40, (1996). “Seismic evaluation and retrofit of concrete buildings,” California, Applied Technology Council.

[5] Canbay, E., Ersoy, U. and Ozcebe, G., (2003). “Contribution of reinforced concrete infills to seismic behavior of structural systems,” ACI Structural Journal, Vol. 5, pp. 637-643.

[6] Cardenas, A.E., Hanson, J.M. and Corley, W.G. (1973). “Design provisions for shear walls,” ACI Structural Journal, Vol. 70, pp. 221-230.

[8] Chiou, Y.J., Mo, Y.L., Hsiao, F.P., Liou, Y.W., and Sheu, M.S., (2003). “Experimental and analytical studies on large-scale reinforced concrete framed shear walls,” ACI Structural Journal, Vol. 211, pp. 201-222.