刚性层深度及层间接触状态对FWD动载响应及反算结果的影响

Influence of Rigid Subjacent Bed Depth and Contact Status between Layers on FWD Dynamic Reflection and Back-calculation Modulus

基于弹性动力学平衡方程,进行Laplace、Hankel联合积分变换,利用传递矩阵的方法,可得任一深度处应力位移与表面应力位移关系。讨论了FWD动荷载形式下下卧刚性层埋深及层间接触状态对表面弯沉的影响。计算结果表明,下卧刚性层的埋深变化对动弯沉盆的形状影响不大,但对数值大小影响明显,下卧刚性层埋深较浅时,面层与土基模量反算结果明显偏大,基层反算结果却显著偏小。层间接触较差时,路面各结构层的反算模量都显著偏小。因此建议模量反算之前,首先对刚性层深度及层间接触状态进行分析,避免对反算模量结果造成很大影响。

Based on the elastic dynamic equilibrium differential equation of the axisymmetric, Laplace, Hankcl mixed integrals and transfer matrix method are employed to obtain the relation of stress and deflection between a certain depth and surface.The surface deflection is discussed considering the influence of rigid subjacent bed depth and contact status between layers.The result indicates that the depth of rigid subjacent bed has obvious effect on the value of surface deflection and has little effect on the shape of defection basin. If rigid subjacent bed is shallow, the back-calculation modulus of surface layer and soil is higher, but the modulus of base is lower.If contact status between layers is poor, the back-calculation moduli of all layers are lower.So rigid subjacent bed depth and contact status should be evaluated to avoid producing great deviation before back-calculation.