动载下土工格栅加筋桥台挡墙承载性能分析

为研究加筋土桥台结构在顶部条基动载作用下的动力响应问题，通过MTS伺服加载系统施加循环动载，开展室内加筋桥台挡墙动载破坏试验，对比分析3种格栅长度和3类格栅型式的加筋土挡墙沉降及面板水平位移、土压力、筋材应变等参数的分布规律，揭示加筋桥台挡墙的动力承载性能。试验结果表明：在循环动载下不同格栅长度及型式的加筋桥台挡墙破坏模式存在差异，M、A、B型格栅加筋长度 1.0H（H为挡墙高）的挡墙破坏模式均为冲切剪切破坏，A、B型格栅 0.7H和 0.4H的挡墙破坏模式为局部剪切破坏。加筋桥台挡墙面板侧移随筋材长度增加依次减小，A型格栅加筋土挡墙侧移系数总体上相比B型小。桥台挡墙因加筋格栅长度及型式不同导致动土压力衰减规律差异明显，当 1.0H时M型及A型筋材竖向动土压力衰减系数沿墙高呈抛物线函数模型，当 0.7H时，A型和B型筋材竖向动土压力衰减系数沿墙高皆呈指数函数模型。

Bearing capacity analysis of geogrid reinforced abutment retaining wall under dynamic load

To investigate the dynamic response of reinforced earth abutment structure under dynamic action of the top strip footing, dynamic load failure test of the indoor reinforced abutment retaining wall was carried out by MTS servo loading system with cyclic dynamic load. Comparative analysis of the reinforced earth retaining wall parameters with three grid lengths and three grid types, such as settlement of reinforced soil retaining wall, horizontal displacement of the panel, earth pressure and strain of the reinforcement, etc. hence revealing the dynamic bearing capacity of reinforced abutment retaining wall. The test results show that there are differences in failure modes of different geogrid lengths and types of reinforced abutment retaining walls under cyclic dynamic loading. When 1.0H, the failure modes of retaining wall of M-A-B-type geogrids are punching shear failure. And when 0.7H and 0.4H, the failure mode of retaining wall of A-type and B-type geogrids are local shear failure. The lateral displacement of the reinforced abutment retaining wall panel decreases with increasing reinforcement length, and the lateral displacement coefficient of the A-type grid reinforced retaining wall is generally smaller than that of the B-type. Due to the length and type of the reinforced geogrid, the abutment retaining wall has significant difference in the attenuation law of the dynamic earth pressure. When 1.0H, the vertical dynamic earth pressure attenuation coefficient of M-type and A-type geogrids are parabolic function along the wall height. When 0.7H, the vertical dynamic earth pressure attenuation coefficient of A-type and B-type geogrids are exponential function along the wall height.