铅芯橡胶支座非理想工作状态下的力学试验研究

在大震作用下，桥墩会产生较大的变形，从而使得与之相联的铅芯橡胶支座处于整体倾斜、转动等非理想的工作状态，这样会对铅芯橡胶支座产生较大的影响。本文针对这样的情况，设计并进行了铅芯橡胶支座处于非理想工作状态下的水平性能试验研究，对比了铅芯橡胶支座非理想工作状态下与正常工作状态下的差异，分析了支座滞回曲线、水平等效刚度、等效阻尼比等随倾斜角度和剪切应变的变化规律，以及墩柱倾斜角度对支座的减隔震性能发挥的影响。试验结果表明：支座的倾斜状态容易导致钢板与橡胶脱胶，严重时会出现起鼓、开裂甚至爆裂。铅芯橡胶支座的水平等效刚度随倾斜角度的增大而减小，等效阻尼比随倾斜角度的增大而增大。铅芯橡胶支座边界倾斜会限制支座水平减隔震性能的发挥，随着角度的增大影响更加明显，最大会降低40%。

Experimental Study of Lead Rubber Bearing Under Non-Ideal Working Condition

Under the large action of earthquakes, the deformation of pier will be great. So that Lead Rubber Bearing (LRB) associated with pier is in a non-ideal working state such as overall tilting and rotation, which will result in a large influence on the performance of LRB. In this paper, the horizontal performance test of LRB under non-ideal working condition is designed and carried out, and the difference between the non-ideal working state of LRB and the normal working state is compared. The hysteresis curve, the horizontal equivalent stiffness, the equivalent damping ratio vary with the inclination angle and the shear strain, and the influence of the inclination angle of the pier on the seismic isolation performance of the bearing are studied. The test results show that the inclined state of the support can easily lead to degumming of the steel plate and the rubber, and in the case of serious, there will be drumming, cracking or even bursting. The horizontal equivalent stiffness of LRB decreases with the increase of the inclination angle, and the equivalent damping ratio increases with the increase of the inclination angle. The slope of LRB boundary will limit the horizontal isolation and isolation performance of the bearing. The effect will be more obvious with the increase of the angle, and the maximum will be reduced by 40%.