Study On Stability Of Loose Sand Slopes Subjected To Rainfall

The mechanism study of rainfall-induced landslides is an important research topic over all the world,and many researchers and engineers are very concerned about it. Furthermore, the losses of human life and property caused by sudden landslide of loose sand slope is so heavy. Therefore, the research about that how the factors cause this kind of landslide is necessary. Based on the mechanism, rainfall-induced landslides can be predicted and even prevented. In this paper, ther are two factors, the different thickness of slope and intensity of rainfall, which affect the stability of loose sand slope are studied based on model test. At the same time, a numerical analysis of the model test is done in this paper.First, a rainfall system meeting the test requierments is evented, and the monitoring system used in the small model test is promoted. Second, by comparing the rain holds, the pore water pressure changes, the displacement of slope, failure modes the influence of thickness of slope and intensity of rainfall on the stability of slope is analized through four model tests. From the tests, we can know that satatic liquefaction may appear in loose sand slopes under rainfall. Under rainfall conditions, the greater rainfall intensity, the greater change in soil pore water pressuer, the greater change of displacement of soil, the easier to generate static liquefaction. At the same time, the thick slope will induce that pore water pressure change fast, the dispalcement of soil will enhance, the satability of slope will decrease, and it's easier to generate static liquefaction. And continuous rainfall will induce greate erosion, and the instability of slope will decrese. Under the same condition, if the rain erosin situation is not serious, the possibility of static liquefaction will inceaase.Finally, according to the characteristics of sand used in the model tests, combination of analysis of SEEP/W and SLOPE/ W are done to comparison of rainfall duration, slope and rainfall intensity in the thickness of rainfall during the course of the effects of slope stability safety factor. The results show that under the same rainfall intensity, the same rainfall time, the thicker slope, the latter and slower the safety factor declines, under the same slope of the thickness, the same rainfall time, the greater rainfall intensity, the faster the safety factor decline.