填方路基抗震安全是西部公路建设的关键技术问题之一。以“5.12”汶川地震灾区典型填方路基为背景,采用红层软岩和石英砂为模型路基材料,设计并完成比例为1∶20的大型振动台模型试验。在满足相似律的条件下,通过输入不同地震波类型、频率和振幅,系统地研究填方路基在强地震动作用下的动力响应和损伤破坏过程。试验模型尽可能全面地模拟影响填方路基地震响应的各种主要因素,包括路基与挡墙动力相互作用、路基施工过程、边界条件等。试验结果表明,加速度沿水平方向的响应呈现明显的非线性特征;总体上,模型路基对输入地震波具有明显的放大作用,在水平向地震波作用下,沿路基坡面向上,加速度峰值放大系数呈现递增趋势,路肩附近急剧增大,在逐级增加的输入地震作用下路基发生多处开裂。试验模拟呈现填方路基在地震作用下的响应及其损伤破坏过程,确定抗震薄弱部位,为全面评价路基的抗震性能提供相应的参考。 Seismic safety of filled embankment is one of the key technical problems in the construction of western highway. Based on the typical embankment of “5.12 ” Wenchuan earthquake-stricken area, the red bed soft rock and quartz sand were used as the model subgrade materials, and the large-scale shaking table model test was designed and completed with a ratio of 1:20. Under the condition of similarity law, the dynamic response and damage process of filled embankment under strong ground motion are studied systematically by inputting different types, frequencies and amplitudes of seismic waves. The test model simulates all the main factors affecting the seismic response of filled embankment as fully as possible, including dynamic interaction between subgrade and retaining wall, subgrade construction process and boundary conditions. The experimental results show that the response of the acceleration along the horizontal direction shows obvious nonlinear characteristics. In general, the model embankment has a significant amplification effect on the input seismic wave. Under the action of horizontal seismic waves, the peak amplification factor of the acceleration appears upward along the slope of the subgrade, Trend, the sharp increase in the vicinity of the shoulder, in a step-by-step increase in the earthquake under the action of many cracks in the roadbed. The experimental simulation shows the response of the embankment under earthquake and the process of damage and destruction, and determines the weak parts of the earthquake-resistant zone, so as to provide reference for comprehensively evaluating the anti-seismic performance of subgrade.