Experimental Investigation of Internal Instability of Soils in Embankment Dams and Their Foundations

Two types of suffusion tests were conducted. The downward flow seepage test aims at identifying the types of soils that are susceptible to suffusion, whereas the upward flow seepage test aims at identifying the hydraulic gradient at which suffusion is initiated. The investigation analyzes the results of these tests, and the results of similar seepage tests conducted by previous investigators, and recommends new approaches to assess the internal stability of a soil.