Nonlinear Coupling Research Of Seepage-Stress Field In The Thick Overburden Layer Of Dam Base

The thick overburden layer is a special groundsill that is provided with loose straucture,incontinuous lithology,complicated styles of formation and whose change of mechanical characters takes on asymmetric. When the high earth—rockflll dam is founded, it is very significant to research distributing of seepage and stress field effectively and with reason for estimating correctly stabilization of body and base of dam. Seepage and stress field are tied together within the layer that are interactional. This is a coupling issue about research to them.In order to find out the essence of diversified models and advantage and disadvantage of their realization, the analysis and comparing about them are developed. Using the got survey information, geologic conditions are analyzed, and penetrability of the deep and thick overburden layer, rock and soil in the basis of dam are discussed in detail in the bed of pubugou river. The result is found that the deep and thick overburden layer is soft groundsill whose geologic characteristic will changed when load is thrown on it.Based on some preceding research work, ground on Kozeny-Carman equation, the nonlinear coupling numeric model is established about seepage field and stress field on the dam and its surroundings. This model is exerted to the practice and the evolutive laws are obtained following time and space about porosity and in the deep and thick overburden layer. Simultaneity, regression analysis is carried out about the hydraulic conductivity value and corresponding effective stress value that are solved by the above simulation and the relation curves are described. The relation is applied to FEMLAB Multiphysics Modeling software in order to probe into its nonlinear coupling work.Discussing the sensitivity grade between leakage quantity of the base of the dam and average hydraulic head gradient through the purdah and penetrability of the purdah and cut-off wall in order to prove they will affect the dam's safety. The sensitivity analysis is processed about anisotropy of the hydraulic conductivity in order that leakage quantity of the base of the dam and average hydraulic head gradient through the purdah are variational following the anisotropic grade in the deep and thick layer.The simulation shows that the nonlinear coupling work reflect the natural laws better about seepage field and stress field. So, it is necessary to introduce this mechanism.