RC剪力墙地震损伤试验研究

Experimental study of the damage of RC shear walls under low cycle reversed loading

为了研究地震作用下RC剪力墙的损伤演化过程,通过改变轴压比、边缘配箍、混凝土强度和加载方式,对9榀RC剪力墙试件进行单调与低周反复加载试验,考察试件经历不同次数循环加载后其损伤及其力学性能的变化规律,从损伤的角度分析不同设计参数及加载方式对试件荷载-位移滞回曲线、骨架曲线、强度和刚度退化、变形能力、累积滞回耗能等的影响,同时探讨试件残余变形与位移幅值的关系。结果表明,随着循环次数和位移幅值的增加,试件损伤逐渐累积,使其刚度、强度逐渐退化,耗能能力以及极限变形能力不断降低;变幅循环加载下试件的损伤发展呈先缓后急的特点,而常幅循环加载下试件的损伤演化过程较为缓慢,损伤发展速率较为平稳。研究结果为进一步建立能够描述RC剪力墙损伤程度的地震损伤模型,揭示损伤对RC剪力墙力学性能的影响提供试验支撑。

In order to study the process of damage evolution of Reinforced Concrete （RC） shear walls, considering different axial compression ratios, boundary hooping, concrete strength and loading histories, nine specimens of RC shear walls were tested under monotonic and cyclic loads. The pattern of damage and mechanical property of specimens subjected to different numbers of cycle loading were investigated. The influence of design parameters and loading history change on loading-displacement curve, skeleton curve, strength and stiffness degradation as well as accumulative energy dissipation capacity were analyzed from the viewpoint of damage , and the relationship between residual deformation and displacement amplitude was discussed. The results show that, with the increase of cycle number and displacement amplitude, the damage of specimens accumulated gradually, which caused strength and stiffness degradations, decreases in energy dissipation capacity and ultimate deformability; the process of damage evolution of specimens was slow in earlier stage and rapid in later stage under variable displacement amplitude cycle loading, while the total process of damage evolution of specimens was slower under constant displacement amplitude cycle loading, and the development rate of the latter was more stable. damage