水平拼缝部位增强叠合板式剪力墙抗震性能试验研究

EXPERIMENTAL STUDY ON ASEISMIC PERFORMANCE OF SUPERIMPOSED RC WALLS WITH ENHANCED HORIZONTAL JOINTS

  • 摘要: 叠合板式剪力墙在水平拼缝部位采用"等钢筋面积"连接时,水平地震作用下的弹塑性变形模式以"摇摆变形"为主,无法达到"等同现浇"的要求。为改善这一状况,提出在水平拼缝部位采用"强连接"的方式,即通过提高水平拼缝抗弯承载力,使构件的塑性部位转移至墙板内部,从而使其抗震性能更接近现浇混凝土剪力墙。该文进行了3个采用"强连接"的叠合板式剪力墙试件以及1个作为对比的现浇混凝土剪力墙试件的拟静力试验,研究了不同轴压比下水平拼缝弯矩超强系数对叠合板式剪力墙抗震性能的影响。结果表明:采用"强连接"叠合板式剪力墙试件的塑性变形出现在墙板内部基础插筋顶部附近和水平拼缝处两个部位,试件变形模式接近现浇混凝土构件,不再以摇摆变形为主;水平拼缝部位弯矩超强程度较大的试件,水平拼缝部位基础插筋屈服也相对较晚;相同轴压比的"强连接"叠合板式剪力墙试件延性和刚度退化情况与现浇混凝土试件相当,耗能能力高于现浇混凝土试件。

     

    Abstract: For the Superimposed RC (SIRC) walls, when the amount of the connecting reinforcement at the horizontal joints equals to that of the longitudinal reinforcement in the precast panels, significant rocking characteristic will appear under lateral loads, and the aseismic performance could not be equivalent to the cast-in-place RC walls. To improve this situation, the "strong connection" manner for the SIRC walls is proposed. That is, through increasing the flexural capacity of the horizontal joints, the inelastic region of the SIRC walls will be transferred from the horizontal joints to the panels, inducing a seismic behavior which is more similar with that of the cast-in-place RC walls. Quasi-static test of three SIRC walls with "strong connections" and one cast-in-place RC wall was conducted to evaluate the effect of the flexural over-strength ratio of the horizontal joints to the aseismic behavior of the SIRC walls under different axial load ratios. The test results indicate that the inelastic behavior of the SIRC wall with ‘strong connections’ occurred both near the top of the protruding reinforcement in the wall panels and at the horizontal joints. The deformation manner of SIRC walls is similar with that of the cast-in-place RC walls, and the rocking deformation mode was avoided; the more the flexural over-strength ratio is, the later the protruding reinforcement yielded; the ductility and stiffness deterioration of the SIRC specimens are comparable to those of the cast-in-place specimen with the same axial load ratio, while the energy dissipation capacity of the SIRC specimens is even higher.

     

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