列车振动荷载下路基地基应力应变分析

摘要

应力应变是路基地基系统动态响应的重要指标,也是评价路基与地基行车安全及舒适度的重要依据,因此进一步研究其意义重大.以Biot理论为基础,用数值模拟的方法,分别用线弹性本构模型及弹塑性本构模型(Pastor-Zienkiewicz Mark Model III)分别描述弹性与弹塑性砂土的动力特性,以Mat Lab以及FSSI-CAS 2D等软件为工具,进一步研究富含地下水环境下的弹性、弹塑性砂土路基地基系统在列车通过时的应力应变特征.通过计算得到路基地基系统内部应力应变的具体值及其变化规律,为解决类似问题提供一个新的方法,并可应用于实践.%Stress and strain are the important factors reflecting the dynamic response of subgrade-foundation system and evaluating train running safety and ride comfort. Based on Biot theory and numerical simulation, this paper employs the linear elasticity model and elastic-plastic soil constitutive model ( Pastor-Zienkiewicz Mark ModelⅢ) to orderly simulate dynamic performance of elastic and elastic-plastic sand, and uses Mat Lab and FSSI-CAS 2D software to further analyze the dynamic response of elastic and elastic-plastic water sand foundation under train vibrating load. As a result, the specific numerical values and change laws of the subgrade-foundation are obtained via calculation, which may serve as a new and practical solution.