Earth Dam Seepage And Stability Analysis Under Rainfall Infiltration

Rainfall is the main inducing factors leading to the instability of earth-rockfilldam，it will affect the distribution of pore water pressure in the dam body，Manylandslides have direct and close relationship with rainfall. In recent years，slopeinstability triggered by rainfall more and more frequent. Therefore，the analysis ofrainfall infiltration on slope stability influence and prediction of landslide probabilityof occurrence，has very important meaning in engineering application. This paperstudies on the effect of rainfall on the earth dam seepage and slope stability，using thetheory of saturated-unsaturated seepage and stability analysis of dam slope theory.Seepage field and stability of dam slope are simulated by the finite element softwarewith different rainfall conditions of rain infiltration. The main content of the researchinclude that：（1）This paper expounds the basic theory of saturated-unsaturated seepageproblems，and derives the saturated-unsaturated seepage basic differential equationfrom the physical equation of seepage flow. Based on saturated seepage controlequation，saturated-unsaturated seepage control equation is deduced，boundaryconditions are given under rainfall conditions，and gives its solution condition.（2）The paper introduces several common patterns of rainfall infiltration，andstudies the rainwater infiltration process in soil slope. In order to better understand thenumerical simulation of rainfall infiltration process and arrive at a correct analysis ofthe results，discusses the key problems what should be noticed in the process ofimplementation of the numerical simulation. For example，the rainfall infiltrationinitial boundary condition settings，definition of the soil water characteristic curveand permeability coefficient function.（3）Explaining the theory of earth slope stability analysis under the condition ofrainfall infiltration，introducing several commonly methods of slope stability analysis.Such as the limit equilibrium method, the circular slice method. Regarding rainfallinfiltration as an important influence factor in slope stability analysis，study on theinfluence of rainfall infiltration on slope stability mechanism. （4）Refer to the Bintian reservoir in Poyang County of Jiangxi province as anengineering instance，using a simple two-dimensional earth dam slope model underdifferent rainfall conditions for dam seepage and stability analysis，to calculate theseepage field under different rainfall intensity，rainfall duration，rainfall type andantecedent rainfall conditions. Base on the seepage calculation result to analysis slopestability，get the corresponding case dam slope stability safety coefficient variationlaw. Study on the stability of dam slope safety coefficient of rainfall intensity, rainfallduration, rainfall patterns and antecedent rainfall sensitive degree.The research work of this paper is trying to improve and perfect the seepage andstability of soil slope numerical calculation method，to further understand the slopeinstability mechanism and laws by rainfall induced. It can provide a reference for thefuture reservoir reinforcement，can also provide a scientific basis for predictinglandslides during the rainy season and the dam reservoir dam design.