地震作用下双薄壁高墩刚构桥桥台处的碰撞效应及减碰措施

发布时间：2018-07-21 20:46

【摘要】：针对双薄臂高墩连续刚构桥两侧桥台处主梁与背墙的碰撞现象,基于桥台-背土作用简化模型和Kelvin碰撞模型,采用非线性时程法研究碰撞对双薄臂墩地震剪力、弯矩、曲率和位移,以及支座纵向变形的影响。提出可牺牲背墙、阻尼器、加强型横系梁等三种减碰措施,并对比分析其减碰效果。研究表明:碰撞会显著增大高墩的地震内力和曲率响应,降低墩顶位移和支座的纵向变形;碰撞刚度的变化对碰撞效应的影响在20%以内;可牺牲背墙和阻尼器两种减碰措施均可大幅降低桥墩的地震内力和曲率,使其接近不考虑碰撞时的状态,阻尼器同时还可以保护支座不超过容许变形,而可牺牲背墙则会导致支座的地震破坏;加强型横系梁不能发挥减碰作用,反而会增大桥墩的地震响应。
[Abstract]:In view of the collision phenomenon between the main beam and the back wall at the abutment of the continuous rigid frame bridge with double thin arm high pier, based on the simplified model of abutment-backsoil interaction and Kelvin collision model, the nonlinear time-history method is used to study the seismic shear force and bending moment of the collision to the double thin arm pier. The effects of curvature and displacement, as well as the longitudinal deformation of the bearing. Three kinds of collision reduction measures, such as sacrificial back wall, dampers and reinforced crossbar beams, are put forward, and their impact reduction effects are compared and analyzed. The results show that the impact can significantly increase the seismic internal force and curvature response of the high pier, reduce the displacement of the pier top and the longitudinal deformation of the support, and the impact of the impact stiffness on the impact effect is less than 20%. Both the sacrificial back wall and the damper can greatly reduce the seismic internal force and curvature of the pier and make it close to the state when the collision is not considered. The damper can also protect the bearing from exceeding the allowable deformation. On the other hand, the sacrificial back wall will lead to the earthquake damage of the support, and the strengthened transverse beam will increase the seismic response of the pier instead of reducing the impact.
【作者单位】：重庆交通大学土木工程学院;重庆交通大学山区桥梁与隧道工程国家重点实验室培育基地;
【基金】：交通运输部应用基础研究计划项目(2014319814210) 重庆市基础与前沿研究计划项目(cstc2015jcyjA30014) 山区桥梁与隧道工程国家重点实验室培育基地开放基金(CQSLBF-Y14-2) 国家自然科学基金资助(51408089)
【分类号】：U442.55

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