考虑应力状态的接触流土试验研究

Experimental study on contact soli flow considering stress condition

接触流土作为渗透变形的一种型式,通常由接触面两侧粗细颗粒的粒径比来判别。结合试验研究了应力状态对接触流土临界坡降的影响,结果发现在粗细颗粒的接触带,在同样的水力梯度下,即将流入粗颗粒孔隙之中的细颗粒内部的压应力越大,接触流土破坏越难发生,且发现接触流土临界坡降随着压应力的增大而增大。由此得出:在控制反滤料颗粒级配的基础上,采取结构措施增大细颗粒内部的压应力,可以使反滤层的运行更加稳定。

As one type of seepage deformation, contact soil flow is often identified according to the size ratio between coarse granule and fine granule in contact area. The influence of stress condition on critical gradient of contact soli flow has been studied through experiment. The result show that, under the same hydraulic gradient, in the contact strip of coarse granule and fine granule, the larger the pressure stress in fine granule, the more difficult the contact soil flow occur, and the critical gradient of contact soil flow increase with pressure stress. The conclusion is obtained that on basis of controlling grain gradation of filter material, increasing internal pressure stress of fine granule through the structural measures can make filter layer more stable.