带悬吊质量结构的多维地震反应

Seismic response of structure with suspended mass

摘要:

为了研究带悬吊质量结构体系在地震动水平-竖向-摇摆耦合作用下的动力效应,推导了地震动水平-竖向-摇摆耦合作用下带悬吊质量结构体系的动力方程,提出一种改进的摇摆分量时程获取方法,并以某带悬吊质量阀厅结构为原型,进行1∶10缩尺模型振动台试验,探讨采用不同长度的钢索和弹簧悬吊质量时,结构在水平-竖向、摇摆-竖向和水平-竖向-摇摆耦合地震动作用下的地震效应．结果表明:相较于水平地震动作用下,悬吊质量对摇摆地震动作用下主体结构的减震效果更加显著;随着钢索或弹簧长度增加,悬吊质量对主体结构的减震效果降低;将拉索由钢索改为同等长度的弹簧后,结构顶层的加速度响应和位移响应变化不大,但拉索动拉力却明显减小,当采用悬吊质量作为质量摆减震系统时,拉索应尽量采用弹簧或拉压刚度较低的构件．

Abstract:

To study the dynamic response of the structure with suspended mass under coupled horizontal, vertical and tilt ground motions, the dynamic equation of the structure under coupled horizontal, vertical and tilt ground motions was derived. A modified method was proposed to obtain the tilt component. Taking a valve hall with suspended mass as prototype, the shaking table test of a 1∶10 scale model was carried out, and the seismic responses of structure under coupled horizontal-vertical, tilt-vertical and horizontal-vertical-tilt when different lengths of steel cable and spring to hang the mass. The results show that, compared with under horizontal component, the damping effect of suspended mass on main structure under tilt component is more obvious. The damping effect of suspended mass on main structure decrease as the length of steel cable or spring grows. When using spring of the same length to replace steel cable, the changes in acceleration and displacement on the top of structure are not big, but the dynamic tension of cable decreases. Thus, when suspended mass is used as damping system, the cable should employ spring or the member with low axial rigidity.