Seepage Failure of Sand in Three Dimensions –Experiments and Numerical Analyses–

摘要

In the deep and large excavations of soil with a high ground water level, sheet piles or diaphragmwalls are often used to retain soil and water. Under such conditions, three dimensional seepage flow occursthrough soil, and seepage failure is often a problem. The three-dimensionally concentrated flow lowers thesafety factor for seepage failure more than the two-dimensional condition. To clarify the seepage failuremechanism, seepage failure experiments are conducted under three-dimensional flow conditions for variouscases. Secondly, Prismatic failure concept 3D is presented and analyses of FEM seepage flow and stabilityagainst the seepage failure of soil are carried out. The characteristics of seepage failure of soil in threedimensions are then discussed from the viewpoint of experiments and numerical analyses. Finally whether ornot the axisymmetric approximation is appropriate to model three dimensional seepage failure phenomena isdiscussed.