黄海新 李炫钢 李帆 张仲帆 周彤

摘 要：板式橡胶支座的老化和偏压甚至脱空对桥梁抗震安全至关重要。将板式橡胶支座进行室内老化试验并测得弹性模量，按老化程度和轴压偏心大小共分16个工况，采用拟静力试验对比分析了热老化、偏压脱空及其耦合下支座的抗震性能指标及变化规律。结果发现：偏心受压下支座滞回曲线较为狭长，滞回曲线面积和等效阻尼比减小，水平等效刚度增大;老化后的支座剪切变形量缩减，在给定的位移幅值下，因滑移量占比加大，滞回曲线更为饱满，对应的等效阻尼比增大;老化和偏心耦合状态下的滞回曲线斜率更为平缓，支座耗能能力明显削弱;位于梁端或长期处于偏压状态的普通板式橡胶支座在地震中存在因单向累计滑移过大而脱落的风险。桥梁维护中应对支座底面采取限位措施，并对偏心受压严重的支座进行及时调整。

关键词：桥梁工程;减隔振性能;拟静力试验;橡胶支座;热老化;偏心受压

中图分类号：U441;TU317 文献标志码：A 文章编号：2096-6717（2021）03-0051-08

Abstract： The aging eccentric compression， and even void of plate rubber bearings are very important for the seismic safety of bridges. The elastic modulus of plate rubber bearing was measured by indoor aging test. According to the degree of aging and eccentric compression the quasi-static test is divided into 16 cases， and the seismic performance indexes and change rules of the bearings under thermal aging， eccentric pressure and coupling are compared and analyzed. The results show that the hysteresis curve of the bearings under eccentric compression is relatively narrow. The area and equivalent damping ratio of the hysteresis curve decrease， and the horizontal equivalent stiffness of bearing increases. After aging， the shear deformation of the bearings decreases， the hysteresis curve is fuller with the increase of slip ratio for the given displacement amplitude， and the corresponding equivalent damping ratio increases. Under the condition of aging and eccentric compression， the slope of hysteresis curve is more gentle， and the energy dissipation capacity of bearing is obviously weakened. It is found that the beam end or the common plate rubber bearing that is under eccentric compression for a long time has the risk of falling off due to the excessive unidirectional accumulative slip in earthquake. It is suggested that in bridge maintenance， a limit device should be set on the underside of the bearing and timely adjust the bearing with severe eccentric compression.

Keywords： bridge engineering; damping performance; pseudo static test; rubber bearing; thermal ageing; eccentric compression

板式橡胶支座以其成本低、承载和变形能力优良而在中小跨径梁桥中被广泛应用。在桥梁减隔震设计中，板式橡胶支座因较小的阻尼比而通常被视为普通支座。但近二三十年的地震灾害表明，板式橡胶支座的剪切变形、摩擦滑移耗散了部分能量，减轻或延缓了桥墩的损伤[1]。因此，一些學者开始对板式橡胶支座的减隔震性能进行深入研究。其中，范……