| In southwest of China where terrain is complex, Landslide is a serious threat to thesafety of people’s lives and property. These unstable slope is often developed in the twosides of the river, and affected by rainfall, and correlated closely with the rainfallinfiltration. Because of the rainfall infiltration not only will result in directly reducingin shear strength of rock and soil, but also change the seepage in unsaturated area of thelandslide and ground water level line, and resulting in changing in Dynamic pressureand Hydrostatic pressure in unstable slope, and resulting in the slope stability towardunfavorable direction.So analysis of the development of slope stability of Mollo landslide has a veryimportant significance under influence of saturated-unsaturated seepage, After theanalysis of saturated-unsaturated seepage field under rainfall infiltration. On the basisof rainfall infiltration and the theory of saturated-unsaturated theory, This paperanalyzes the characteristics of seepage field of Mollo landslide in the condition ofrainfall infiltration, The Formation and variation of Pore water pressure and transientsaturated zone under rainfall infiltration. On this basis, This paper researches thestability of landslide by using the method of finite element analysis. This paperfocuses on the influence of different rainfall intensity duration and different rainfallduration and after the rain stopped of these factors on slope stability, therefore, mainlyfrom the following several aspects research. The following main research resultsobtained in this study:1.This paper Find out the engineering geological conditions and the basichydrogenologycal condition and deformation features of MoLuo landslide, At thesame time, we revealed the failure mechanism about rainfall infiltration of the Moluolandslide.2. The changes of the seepage field in MoLuo landslide about different rainfallintensity and rainfall duration and rainfall forms under different conditions aresimulated and analyzed, also we reveals variation in different rainfall conditions ofgroundwater level in landslide.(1) Effects of rainfall duration is short of rain on the underground water level is relatively small, And it reveals that if the small rainfall intensity and duration is notlong, the effect on seepage will be small.(2) If the rainfall intensity is relatively large, infiltration peak will quickly reachthe level of underground water, underground water level will began to rise at anearlier time. On the other hand, if the rain lasted for a long time, the undergroundwater level rose to high, and even the whole rock and soil saturation, this can explainwhy the slope is often instabilityin in the greater intensity of rainfall.3. This paper Discussed the mechanism of slope instability caused by rainfall,and analyzed stability of the Mo Luolandslide in different rainfall conditions, resultsshow that:(1) In the same rainfall time, the relationship between the safety factor ofslope and rainfall intensity is very close, in general, The safety factor will decreasegradually with rainfall enhancement, If the intensity of rainfall is small and therainfall time is short, The changes of slope stability will be small; in the same rainfallintensity, safety coefficient of slope sensitivity becomes small with rainfalldurationand to growth.(2) For a short diachronic strong rainfall, slope stability will decreases at thefastest rate. The slope groundwater level sustained reductions after the rain stopped,And the safety coefficient increased gradually. |
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