隔震曲线连续梁桥铅芯橡胶支座参数优化

为了提升铅芯橡胶支座（LRB）在隔震曲线梁桥中的减隔震效果，该文对LRB力学性能参数进行了优化分析。首先，采用ANSYS建立了某三跨隔震曲线梁桥有限元模型，考虑LRB屈服力、初始刚度及屈服后刚度等性能参数的影响，对该桥进行非线性时程分析，得到了结构关键地震响应随支座力学性能参数的变化规律，并确定了支座参数的合理取值范围。在该支座参数区间内，又以墩底剪力之和为目标函数，基于零阶优化算法，对LRB力学性能参数进行了优化。结果表明：屈服力、初始刚度及屈服后刚度对隔震连续梁桥地震响应有显著影响；隔震支座参数优化后，使得隔震支座峰值位移得到了有效控制，同时不显著增大墩底剪力，且边墩与中墩墩底剪力差值明显缩小，各墩受力更趋均衡。

PARAMETER OPTIMIZATION OF LEAD RUBBER BEARINGS OF AN ISOLATED CURVED GIRDER BRIDGE

In order to improve the performance of an isolated curved girder bridge with lead rubber bearing (LRB), the mechanical parameters of LRB are analyzed and optimized. Firstly, the finite element model of a three-span isolated curved girder bridge is established by ANSYS. Nonlinear time history analyses are conducted with consideration of impact of yield force, elastic stiffness and post-yield stiffness. It is found that the key seismic responses of structure vary with mechanical parameters. The reasonable ranges of the parameters of isolated bearings are determined. Taking the sum of the pier base shear as the objective function, the mechanical parameters of LRB are optimized based on the zero-order optimization algorithm. Results show that yield force, elastic stiffness and post-yield stiffness have significant effect on seismic responses of the isolated curved girder bridge. When the bearings parameters are optimized, the peak displacement of the bearings is effectively controlled without increasing the base shear of the piers distinctly. The differences of shear between the side piers and the middle piers are reduced, and the shear distribution of each pier becomes uniform.