公路桥梁拉索式连梁装置设计参数化研究

Parametric design of unseating prevention devices for highway bridges

作为公路桥梁的抗震措施,防落梁系统是针对落梁震害的减、抗震设计方法,由梁搁置长度、限位装置和连梁装置构成。连梁装置是结构遭遇超预期地震作用时,保证桥梁结构不发生落梁震害的最终安全保护措施,其防落梁效果受到各种设计参数的影响。结合国内外已有的连梁装置设计方法,对设置不同设计参数拉索式连梁装置的结构进行地震响应分析,研究设计参数对连梁装置防落梁效果及其内力的影响。结果表明,连梁装置的防落梁效果随着拉索长度、设计位移量的增大有所减小,但设计参数取值较小的连梁装置内力较大,部分超过连梁装置的设计承载力。

As an aseismatic measure of highway bridges,collapse-proof system is one solution for seismic design and retrofitting,which consists of adequate length seat,seismic restrainers and unseating prevention devices.Unseating prevention devices are the ultimate security installment to prevent the girders form falling off the piers when bridge is hit by earthquake,and their preventing effects are influenced by design parameters.Based on the related design standards at home and abroad,the seismic responses of structures with different cable-unseating prevention devices were analysed.The influences of design parameters on the pressure of unseating prevention devices and the effect of collapse-proof were investigated.The result show that the effect of collapse-proof decreases as the cable length and the design value of displacement increase,and the pressure of unseating prevention devices is larger than the design bearing capacity while the prarmeters are both smaller.