底部铰支自复位钢筋混凝土剪力墙设计与性能研究

为克服传统钢筋混凝土剪力墙在遭受较大地震时易发生墙脚压溃形成塑性铰等问题,减小结构残余位移,提出一种底部铰支自复位钢筋混凝土剪力墙。通过将传统剪力墙破坏严重的底部进行替换,上部墙板通过V型连接梁与基础铰接,两侧墙脚位置处布置具有双线性滞回特性的复位支撑,将墙板传递的内力解构,弯矩由复位支撑单独承受,在墙体底部形成弹性旋转约束的方式,实现了剪力墙较大弹性侧移,从而降低墙体损伤和残余位移。数值模拟分析了普通钢筋混凝土剪力墙(SW)和相同截面的自复位钢筋混凝土剪力墙(SC-SW)在低周往复荷载下的承载能力、耗能能力、变形能力及损伤分布。结果表明:SC-SW通过合理设计可达到与SW相同初始刚度和承载力,同时延性提高了26.52%;损伤水平明显小于SW,避免了以墙体塑性受损而吸收能量的耗能方式;残余位移明显减少,复位效果较好。

DESIGN AND BEHAVIOR STUDY ON BOTTOM HINGED SELF-CENTERING REINFORCED CONCRETE SHEAR WALL

The foot parts of traditional reinforced concrete shear walls are prone to crush and form plastic hinges subjected to large earthquakes. In order to overcome this problem and reduce the residual drift of the structure, a bottom hinged self-centering reinforced concrete shear wall is proposed. To achieve large elastic lateral drift of the shear wall, the severely damaged bottom of the traditional shear wall is replaced, the upper wall panel is attached to the foundation through a V-shaped connecting beam in a hinge, and self-centering braces with bilinear hysteresis characteristics are installed at both sides of the wall; thus the internal force transmitted by the wall is distributed, the bending moment is resisted by self-centering braces alone, and an elastic rotation constraint forms at the bottom of the wall, thereby the residual drift of the wall is reduced. Numerical simulations are carried out to analyze the bearing capacity, energy dissipation, deformation capacity and damage distribution of traditional reinforced concrete shear wall (SW) and self-centering reinforced concrete shear wall (SC-SW) with the same section under low cyclic reversed loading. Results indicate that the SC-SW achieves the same initial stiffness and bearing capacity as SW through reasonable design, and the ductility increases by 26.52%; the damage state of SC-SW is significantly smaller than that of SW, because the energy dissipation of SC-SW is not through the plastic damage of the wall; the residual drift of SC-SW is obviously reduced, showing good self-centering effect.