The paper introduced several construction methods,their features and related important matters of the dike foundation clearance in Tongjiang City.

It was applied in the engineering of Songli yard to its flood-controlbank foundation process.

Analyses on seepage field in levee and its foundation under typical conditions;

This paper discusses the lithology formation of dike and foundation, basing on this, it analyzes the danger causation element of critical engineering,weakly section and puts forward the prevention and danger removement measure.

Aiming at the different seepage control measures applied in the levee engineering of Niutun River, the seepage status of levee foundation is analyzed by using the water level information of measuring holes obtained from the monitoring section of each levee.

Experimental studies on piping in single- and two-stratum dike foundations;

The application of seepage prevention and reinforcement technique for dike foundation;

From the tests, it can be concluded that suspended cutoffs can effectively increase the average critical horizontal seepage gradient of dike foundation and decrease the risk of piping.

Through the analyses on dangerous phenomena,covering layers and natural seepage fields,a safety assessment on the dyke foundation is performed and the necessity of dyke reinforcement is demonstrated.

The concept of dyke body and dyke base is mixed up due to the formulation of dyke body in Standards for Geological Exploration of Dyke Project and causes some confusion in the current geologic exploration of dyke project.