The Study On Soil Unsaturated Character Under Rainfall Seepage

Landslide is one of the important geological hazards, for its factors and mechanism are variable and complex, it is difficult to be predicted, and it have been under research over the world. Recently, landslide that induced by rainfall become more and more, it result in regard of more and more expert and scholar. The main reason that rainfall induce landslide is rainfall and infiltration change the soil's unsaturated character and the whole seepage field, make the land's stabilization change. Therefore, Research to change of soil's unsaturated character under rainfall and infiltration is very important.The rule about water flow in unsaturated soil and the soil-water characteristic curve are described in this papsr, and it respectively regards moisture content and capillarity head as basic variable to deduce unsaturated seepage control equation. It sets up mathematics general model under rainfall and seepage, puts forward manage method of boundary condition and initial condition.It uses the theoretic solution to the soil whose aquifer depth is infinite under unsteady rainfall seepage which based on Gardner's hypothesis, and the numerical solution to the soil whose aquifer depth is finite under the same condition, it develops program to model different soil under different intensity unsteady rainfall seepage, and gets soil unsaturated character change rule with unsteady rainfall intensity, aquifer condition and soil physical character by analysis and compare.For studying deeply soil unsaturated character under rainfall seepage, numerical solution to the soil whose aquifer depth is .finite under steady vertical and horizontal rainfall seepage is in the paper, it study different soil unsaturated character under different steady rainfall seepage, and gets not only gravity's influence to soil seepage but also soil unsaturated character change rule with steady rainfall intensity, aquifer depth(thickness) and soil physical character by analysis and compare.In the paper, soil unsaturated character's change rule under different rainfall seepage is discussed, and the influence to its change of aquifer condition, rainfall seepage intensity, soil physical character and gravity's exist is get, so it has certain theoretic significance.