层状边坡的地震动输入方法研究

层状边坡是自然界中最常见的边坡之一,研究其动力响应规律对边坡的稳定性评价具有重要意义。为真实模拟弹性波在层状地基中的传播过程,首先建立层状地基的黏弹性人工边界模型,然后根据波动力学理论推导了考虑介质交界面的一次反射的等效荷载计算公式,并通过两层地基算例验证该输入方法的精度;针对层状边坡,采用本文提出的地震动输入方法和一种传统的输入方法分别研究其动力响应规律。研究表明:在两层地基算例中,本文提出的地震动输入方法能较好满足工程抗震的精度要求;在边坡的动力分析中,与传统方法相比,采用本文方法的边坡塑性应变能累积效应更加明显,且动力安全系数相对较小。

Seismic input method of layered slopes

Layered slopes are very common in nature, the study of its dynamic response is of great significance to the evaluation of slope stability. In order to simulate the propagation process of elastic waves in layered foundation, the viscous-elastic artificial boundary model of layered foundation is established firstly, and then the equivalent load calculation formula considering the primary reflection of medium interface is derived according to the wave dynamics theory, and the accuracy of the input method is verified by a two-layer foundation example. For layered slopes, the ground motion model proposed in this paper and a conventional input method are used to study the dynamic response law of the foundation. The results show that according to the two-layer foundation example, the proposed ground motion model can better meet the accuracy requirements of the seismic engineering. Compared with the conventional method, the cumulative effect of plastic strain energy of the proposed method is more evident, and its dynamic safety factor is relatively small in the analysis of slope dynamics.