强震下不同站桥组合体系抗震性能对比研究

Comparative study on seismic performance of different station-bridge composite systems under strong earthquakes

为系统对比不同站桥组合体系抗震性能的优劣,以某实际工程项目为背景,分别建立站桥合一结构与站桥分离结构的三维有限元非线性动力分析模型。在综合考虑墩柱非线性以及扩大基础、砂石垫层及地铁顶板之间非线性滑动摩擦效应基础上,深入探讨了两种结构形式在强震下的动力响应以及桥墩损伤规律。研究表明:在讨论范围内,两种站桥组合体系中桥墩下的地铁车站立柱动力响应均大于其他立柱;而相比站桥合一结构,站桥分离结构可以有效降低地铁车站立柱及桥梁结构中桥墩的弯矩与剪力响应,其墩梁相对位移更小,但存在一定残余位移;同时站桥分离结构中桥墩损伤程度更轻,出现塑性状态的时间更晚。整体而言,站桥分离结构的抗震性能更为优异,但在实际工程中需注意对墩梁相对位移及基础滑移的限位。

In order to systematically compare the seismic performance of different station-bridge combination systems,two three-di-mensional finite element nonlinear dynamic analysis models of station-bridge integrated structure and station-bridge separated struc-ture are established based on a practical project.Based on the comprehensive consideration of the nonlinearity of the pier column and the nonlinear sliding friction effect between the spread footing foundation,the gravel cushion and the subway roof,the dynamic response of the two structural forms under strong earthquakes and the damage mechanism of the pier are discussed in depth.It shows that within the scope of this paper,the dynamic response of the subway station columns under the bridge piers in the two sta-tion bridge combination systems is greater than that of other columns.Compared with the station-bridge integrated structure,the station-bridge separation structure can effectively reduce the bending moment and shear response of the pier in the subway station column and bridge structure.The relative displacement of the pier and beam is smaller,but there is a certain residual displacement.At the same time,the damage level of piers in the station-bridge separation structure is lighter and the plastic state appears later than the ones in the station-bridge integrated structure.In conclusion,the seismic performance of the station-bridge separation struc-ture is better,but in practical engineering,it is necessary to pay attention to the limitation of the residual displacement between the pier and girder,and the foundation slip.