Study On The River Levees Piping Mechanism And Seepage Control Measure

This paper analyzed observed data and risky situation of the levee, carried through the in-depth research of two practical engineering problems as piping and valid prevention piping. Special topics, aiming at the problem in the typical levee of failure by piping example, were theoretically analyzed, numerically computed and tested. The research contents and research result were mainly as follows :(1) acquirement of the critical gradient and design gradient of the piping in the Dingma levee;(2) the relation between piping hazardous degree and the soil layer structure of levee foundation and between piping hazardous degree and the distance of piping occurrence to levee toe;(3) reversible two-way washing method of restoring the effectiveness of relief well;(4) apply of the computational method and formula to design the width, thickness and layout of the covering weight of earth blanket;(5)for the study on the transient flow development procedure of the unsteady levee seepage apply to the computation program(UNSST2);(6) research of the effectiveness and the function of the seepage control of suspension-type cutoff walls. This paper will consumedly increase the level of levee design and levee management. It is also to help control flood.