梯度剪力墙抗震性能试验研究

为了将钢筋混凝土剪力墙的弯剪变形机制和摇摆墙的摇摆机制有效结合，实现两者优势互补以提升结构抗震性能，提出了一种梯度剪力墙，通过降低局部压碎区混凝土强度实现从弯剪机制到摇摆机制的转换，并以约束屈曲钢筋代替普通钢筋，提高摇摆阶段剪力墙耗能能力。该梯度剪力墙具有弯剪和摇摆双重变形机制，且可通过合理设计实现不同机制按梯度次序出现和震后的快速修复。分别对梯度剪力墙试件和普通钢筋混凝土剪力墙试件开展拟静力试验研究，并对比分析其破坏特征、滞回性能、承载力、刚度、自复位特性和延性。研究结果表明：低强度混凝土压碎是梯度剪力墙由弯剪机制过渡到摇摆机制的显著标志，受力机制转换前剪力墙以弯剪机制承载，保证其在正常使用和在多遇地震作用下为结构提供足够抗侧刚度；转换后具有摇摆墙功能。与普通剪力墙相比，梯度剪力墙损伤机制明确，延性显著提升，剩余承载力可控，残余变形小。

Experimental study on seismic behavior of shear walls with gradient phases

An innovative shear wall with gradient phases was proposed by combining the flexure-shear deformation mechanism of reinforced concrete shear wall and the rocking mechanism of rocking wall, which took the advantages of the both systems to improve the seismic performance of structures. The transformation from flexure-shear mechanism to rocking mechanism is realized by reducing concrete strength at the local crushed zones, and using buckling restraint reinforcement to improve energy dissipation capacity of the proposed wall in rocking stage. The proposed wall has dual deformation mechanisms of flexure-shear and rocking,which can be designed to exhibit in gradient order,and post-quake reconstruction can be accomplished quickly. The quasi-static tests were carried out on the specimens of the proposed wall and conventional shear wall systems, and the failure mode, hysteretic behavior, bearing capacity, stiffness, self-centering ability and ductility of the specimens were studied. The results indicate that the crushing of low strength concrete is a sign of the transformation from flexure-shear to rocking mechanism for the proposed wall. Before the mechanism transformation, deformation of the proposed wall is controlled by flexure-shear mechanism, and high stiffness can be provided for the structure under normal service or minor earthquakes. After mechanism transformation, the proposed wall has the function of the rocking wall. Compared with conventional shear wall, the proposed wall has improved seismic performance in terms of explicit damage mechanism, higher ductility, controllable residual strength and smaller residual deformation.