整体刚性面板加筋土挡墙振动台模型试验研究

Shaking table tests on reinforced soil retaining walls with full-height rigid facing

加筋土挡墙在大量地震中显示了优越的抗震性能。地震荷载作用下,加筋土挡墙的设计中通常采用拟静力法将动荷载等效为静力荷载。为了对比加筋土挡墙拟静力设计值与实际动力响应值的差异,开展了整体刚性面板加筋土挡墙振动台模型试验。通过位移、加速度、土压力、筋材拉力的测试,得到以下结论:加筋土挡墙内部的加速度分布不均匀并呈现面板、加筋体加速度大于填土加速度的趋势,同时测试的响应加速度值大于设计规范建议值;面板背面土压力作用点高于设计值,但合力仅为物部-冈部理论值的15%～20%;受加速度放大效应及动土压力作用点的影响,墙体的主要变形模式为转动变形;筋材拉力沿墙高非线性分布并且测试合力大于铁路规范建议值。

Reinforced soil retaining walls showed excellent seismic performance in a large number of earthquakes. In the design of reinforced earth retaining wall under seismic loading, the dynamic load can be regarded as equivalent to the static load according to the quasi-static method. A shaking table test of reinforced soil retaining wall with full-height rigid(FHR) facing was carried out to compare the difference between the response obtained by pseudo-static method and the actual dynamic response. The facing displacement, response acceleration, dynamic earth pressure, and the reinforcement load were measured and analyzed. The following conclusions have been drawn: the distribution of the response acceleration in the reinforced soil retaining wall is non-uniform, and the accelerations in the facing and the reinforced zone are larger than those in the retained zone;the response accelerations measured are larger than those calculated from the current design guidelines;although the location of the dynamic earth pressure at the back of the facing is higher than the design value, the resultant force is only 15%-20% of that calculated by the Mononobe-Okabe method;as a result of the effects of acceleration amplification along the facing and the higher location of the dynamic earth pressure, the predominant deformation mode of the FHR facing is rotation;the distribution of the reinforcement tensile force along the wall facing is nonlinear, and the measured force is larger than that calculated from the code in China.