软弱夹层中渗流的接触冲刷机制研究

软弱夹层中的接触冲刷是引起渗透变形及裂缝通道扩展的动力条件。为研究软弱夹层中渗流的接触冲刷机制,建立裂缝水流及泥化土体渗流的耦合模型,其裂缝水流的运动用Navier-Stokes方程及连续性方程共同控制,而裂缝周围泥化土体的渗流运动则用Brinkman-extended Darcy方程及连续性方程共同控制;根据相应边界条件,求出裂缝水流及其周围泥化土体渗流的流速分布。通过将裂缝中水流的流速特征与土颗粒的受力起动特性结合起来,提出软弱夹层产生接触冲刷的临界水力坡度计算方法。经算例计算结果表明,该方法所计算的结果与试验结果基本吻合,具有工程指导意义。

Contact Scouring Mechanism of Seepage in Weak Interlayers

Contact scouring is a dynamic condition that causes osmotic deformation and crack channel expansion in a weak interlayer.In order to study the contact scouring mechanism of seepage in weak interlayer,a coupling model of fracture flow and seepage of muddy soil is established.The Navier-Stokes equation is used to describe the fracture flow,and the Brinkman-extended Darcy equation describes the seepage of the muddy soil around the fracture channel.According to the corresponding boundary conditions,the flow velocity distribution of the crack flow and the surrounding muddy soil seepage are obtained.Based on the failure mode of soil particle sliding start,the critical hydraulic gradient calculation method for contact scouring of weak interlayer is proposed by combining the flow velocity characteristics of water flow in the fracture with the force characteristics of soil particles.The analysis of the example shows that the calculated results are basically consistent with the experimental results and have engineering guiding significance.