车辆荷载下上覆无限大薄板加筋路堤的三维动力响应

利用半解析的方法研究了车辆荷载作用下加筋路堤上覆薄板的动力响应问题。基于Biot多孔弹性介质的波动理论,建立了加筋路堤-道路系统模型。采用上覆Kirchhoff小变形无限大薄板模拟路面板,车辆荷载用4个均布矩形荷载来模拟。在忽略土颗粒自重的情况下,半空间土体引入Biot方程,通过Fourier变换以及边界条件求得变换域里的加筋路堤层位移表达式,采用快速Fourier变换求出时域里的位移。通过数值计算,给出了移动荷载速度、加筋路堤层厚度、板刚度以及加筋率对道路系统位移响应的影响。

3-D dynamic response of infinite plate on reinforced pavement subjected to traffic load

An analytical approach was used to investigate the dynamic response of an infinite plate on reinforced pavement subjected to moving traffic load. Based on Biot＇s dynamic poro-elastic theory, dynamic analytical model of infinite plate and reinforced pavement were established. The pavement system was selected as a model of the Kirchoff infinite thin plate on poroelastic half-space soil medium. The traffic load was represented by four rectangular load pressures. Reinforced pavement embedded between the plate and poro-elastic subsoils was modeled as a transversely isotropic layer. The full dynamic poro-elastic theory of Biot was employed neglecting the body force and the compressibility of solid grain. The governing equations for poroelastic soil and the plate were solved combined with the boundary condition and the contact condition between the plate and the soil by using Fourier transform. The displacements in time domain were obtained by applying the inverse fast Fourier transform （FFT）. Numerical results showed that the effect of load velocity, thickness of reinforced layer, reinforcement＇s ratio and flexural rigidity of the plate on the displacement response of pavement system was significant.