桐梓河特大悬索桥地震响应分析

Seismic Response Analysis of Tongzi River Super Large Suspension Bridge

摘要: 大跨度桥梁是山区交通运输的枢纽和抗震救灾的生命线，一旦在地震灾害中被破坏，后果十分严重。桐梓河特大悬索桥是一座主跨965 m的大跨度双塔钢桁架加劲梁悬索桥，位于贵州省桐梓县，其跨度大、主塔高、结构受力复杂。为评估该桥在地震荷载作用下的安全性，建立空间有限元模型，使用反应谱法对桐梓河特大悬索桥E1、E2级地震下的响应进行计算分析。结果表明：该桥在自重 + 二恒和横向(或纵向) + 竖向E1、E2地震作用下，钢桁梁最大拉应力分别为119.81 MPa、129.12 MPa、153.70 MPa和173.53 MPa，最大压应力分别为87.12 MPa、87.24 MPa、79.09 MPa和79.43 MPa，均处于弹性工作阶段。同样工况下，相应E1、E2作用下混凝土主塔的最大拉应力分别为1.79 MPa、2.09 MPa、2.10 MPa和2.39 MPa，最大压应力分别为9.15 MPa、8.72 MPa、8.26 MPa和7.84 MPa，均满足设计要求。

Abstract: Long-span bridges are the hub of transportation and the lifeline of earthquake relief in mountainous areas. Once damaged in earthquake disasters, the consequences are very serious. Tongzi River Super Large Suspension Bridge is a long-span double-tower steel truss stiffened girder suspension bridge with a main span of 965 m, located in Tongzi County, Guizhou Province, with a large span, high main tower and complex structural stress. In order to evaluate the safety of the bridge under earthquake load, a space finite element model is established, and the response spectrum method is used to calculate and analyze the response of the Tongzi River Super Large Suspension Bridge under earthquakes of magnitude E1 and E2. The results show that under the action of dead weight + secondary dead load and transverse (or longitudinal) + vertical E1 and E2 earthquakes, the maximum tensile stress of the steel truss beam are 119.81 MPa, 129.12 MPa, 153.70 MPa and 173.53 MPa, respectively, and the maximum compressive stress are 87.12 MPa, 87.24 MPa, 79.09 MPa and 79.43 MPa, respectively, which are in the elastic working stage. Under the same working condition, the maximum tensile stress of the main tower under the action of corresponding E1 and E2 are 1.79 MPa, 2.09 MPa, 2.10 MPa and 2.39 MPa respectively, and the maximum compressive stress is 9.15 MPa, 8.72 MPa, 8.26 MPa and 7.84 MPa respectively, which meet the design requirements.