移动荷载作用下层状饱和地基土上无限板的动力响应

DYNAMIC RESPONSES OF INFINITE PLATE ON LAYERED PORO-ELASTIC SUBSOILS SUBJECTED TO MOVING LOADS

利用Biot波动理论、无限大板的弹性理论和TRM方法研究移动荷载作用下层状饱和土地基上覆弹性板的动力响应问题。首先引入两类势函数解耦Biot波动方程。由所引入势函数及二维Fourier变换,得出土体位移、应力及孔压在变换域内的通解。再根据无限大板的弹性理论和传递、透射矩阵(TRM)方法求解变换域内层状土各层的波动系数及板的内力表达式。最后利用IFFT算法得出时间空间域内的解析解。通过具体算例,分析荷载移动速度、土层剪切模量对板内力、土体的动力响应的影响。

Based on the Biot′s dynamic equation and the theory of elastic plate,the dynamic responses of an infinite plate on a layered poro-elastic subsoils subjected to moving loads is studied by the transmission and reflection matrices(TRM) method. Numerical results of bending moment and shear force for the plate are obtained by performing inverse Fourier transformation in the time-space domain. Moreover,the vibration of subsoil due to the moving load is also retrieved. The present methodology is validated by comparing the solutions with some monitoring results. Two examples and the corresponding analysis are presented. Based on the analysis,it can be seen that the occurrence of a softer middle layer inside the layered subsoil will enhance the internal force of beam and the pore pressure considerably. It also indicates that the dynamic response becomes more oscillatory and concentrated to the region of load with increasing the moving load velocity.