双层堤基黏性土盖层渗透稳定判据

双层堤基的渗透破坏首先是从黏性土盖层开始的。现有的渗透稳定判据,一方面可能因低估承压水头而偏于危险,另一方面又忽视了黏性土的渗透特性,大大低估了黏性土的抗渗稳定性,导致评价过于保守。基于对“渗而不流”特征及黏性土渗透特性的认识,揭示洪水期黏性土盖层的“不透水”本质,把黏性土盖层的临界稳定问题归结为点抗裂稳定问题,对双层堤基黏性土盖层渗透稳定判据进行初步探讨。

Basis for Judging the Percolation Stability of Tenacious Clay Covering of Double Layer Dyke Foundation

Failure of double layer dyke foundation by seepage first begins from tenacious clay covering.The existing basis for judging the percolation stability may on the one hand be inclined to be dangerous due to underestimating the artesian head,while on the other hand,be conservative due to overlooking the percolation characterisitcs of tenacous clay,thus underestimating greatly its stability against seepage.Based on the feature of "Percolating while not flowing"and percolation characteristics of tenacoius clay,the author revealed the impermeability nature of tenacious clay covering in flood period and concluded the the problem of critical stability of tenacious clay covering to be that of point crack resistance,thus probing into the basis for judging the percolation stability of tenacious clay covering.