地下结构动土压力简化计算方法研究

基于波动力学理论,考虑土–结构动力相互作用、土介质特性及地震波的传播特性,提出了地震作用下地下结构的动土压力简化抗震设计方法。首先,将土–地下结构体系简化为单自由度的质量–弹簧–阻尼体系。其次,通过建立该体系的波动方程,并进行求解,将自由场响应换算为作用在结构上一点的动土压力,并结合结构周围土体的自由场响应分布特征,可得整个结构上的动土压力分布。最后,以振动台试验结果为基础进行了简化方法的验证,得出本文提出方法能够与试验结果吻合很好。该方法具有概念明确、计算简便、计算效率和精度高等特点,能够求解各类地下结构的地震反应,为地下结构的抗震设计提供了一种简单、实用的工具。

Dynamic soil pressure method for underground structures

Based on the wave mechanics, a dynamic soil pressure method for underground structures under shear wave vibration is proposed. Firstly, taking soil-structure interaction, soil properties and wave propagation characteristics into consideration, the soil-structure system is simplified into a single DOF of mass-spring-damp system. Then the wave equations are established and solved, and the dynamic soil pressure induced by ground shaking at one point of underground structures is obtained by combining the free field response results. Finally, the shaking table test data are used to verify the method. The proposed method has the properties of clear concept, simple calculation, high efficiency and high-accuracy, and therefore, it can provide a simple and practical tool for the seismic design of underground structures.