Experiments on internal erosion in sandy gravel foundations containing a suspended cutoff wall under complex stress states

摘要: Internal erosion is one of the most common failure modes embankment dams or foundations, and simplest effective preventive measure to build a cutoff wall. The soil at bottom wall usually under complex stress states. deeper wall, higher stress. In this study, effects conditions on evolution internal were investigated in sandy gravel foundations containing suspended using newly developed stress-controlled apparatus. Three series tests conducted gap-graded different confining stresses, deviatoric stresses. results these are as follows: (1) discharge permeability decrease with an increase stress, but critical hydraulic gradient increases. (2) second tests, specimen compressed low stress; undergoes shear expansion high (3) third stresses synchronously change, therefore, their combined effect complicated. Under early stage experiment, its structure may change during erosion. When level high, also expansion, degree controlled by both