Analysis Of Slope Seepage Characteristics And Stability Based On Fuzzy Mathematics Under Rainfall

Guangxi is located in the southern region of China, it has humid and rainy all year. In recent years, the development of economy and the increasing of human activities lead to destroy the geological environment. Finally, it improves the possibility of geological disasters and brings great losses to people's lives and property. Therefore, according to the meteorological and topographical characteristics in Guangxi, looking realistic rainfall factor and determining slope stability are very important. In this paper, there is fuzzy comprehensive evaluation on rainfall factors, rainfall factors in rainfall infiltration model are optimized selection by fuzzy mathematic method, improving the objective function value, thus the result agrees with actual situation. Through using Geostudio software to analyze slope stability under rainfall conditions, it can accurately evaluate the slope failure probability. Meanwhile, it can provide some reliable evidences for manual control of slope instability. It shows this study has important theoretical significance and application value. The main results are as follows:(1)In the optimal selection of rainfall factor process, the rainfall intensity, rainfall duration and rainfall type regard as object set.the minimum slope safety factor, slope failure probability, the first to reach the saturation point and transient saturation area regard as evaluation index. The proper rainfall factor are obtained through regression fitting fuzzy comprehensive evaluation which is based on SAS8.1 statistical analysis software.(2)In rainfall infiltration process, Pore water pressure located in slope surface reaches to positive value, Pore water pressure within a certain depth range is improved, and the pore water pressure below the groundwater table has been greater than zero. In addition, A features section is selected to analyze the changes of pore water pressure at different positions, it shows that the farther the distance from slope, the small the pore water pressure would be. Rainfall infiltration depth is 6.5 meters at this soil layer.(3)With the increasing of rainfall intensity, the safety factor decreases rapidly, and the change range also has increased. The slope safety factor decreases with the increases of rainfall duration, after rain stops, slope safety factor does not immediately reduce, it tends to rise, then fall. Different rainfall type has different impact on slope stability, Compared to continuous rainfall, slope is more easily occurred unstable failure under intermittent rainfall.