RESEARCH ON THE INFLUENCE OF RESERVOIR WATERLEVEL COMBINED RAINFALL AND SOIL-WATERCHARACTERISTIC CURVE ON THE PERMEABILITY ANDSTABILITY OF RESERVOIR BANK SLOPE

摘要

In order to study the influence of different un- saturated parameters of Fredlund amp; Xing on the seepage characteristics and stability of the reservoit bank slope under the combined rainfall condition ofthe reservoir water level, the see/w and slope/w in the finite element software Geostudio are used to an- alyze the bank of a certain reservoir in the Three Gorges reservoir area. The permeability characteris- tics and stability of the slope under the action of res- ervoir water level coupled with rainfall are analvzed by numerical simulation. The results show that wher the value of a changes and the value of n does not change, the pore pressures at the upper, middle, and lower monitoring points of the landslide have similar changes. The closer the monitoring point is to the reservoir water level, the greater the initial pore pres- sure there, and the more drastic the pore pressurechanges when the reservoir water level drops. How- ever, when rainfall occurs. the increase in pore pres- sure decreases. When the value of a is large, the im- pact of rainfall on the shallow slope is great, and when the value of a is small, the impact of rainfall on the deep slope is great. The probability of shallow landslides is greatest when rainfall occurs, and the minimum safety factor occurs during the decline of the reservoir water level. If the value of a remains unchanged and the value of n changes, when rainfal occurs during the decline of the reservoir water level, the smaller the value of n, the greater the impact of rainfall on the pore pressure of the monitoring point. Comparing the changes in the safety factor of deep and shallow landslides, the greater the value of n, the greater the impact of rainfall on shallow and deep landslides. The landslide of the reservoir bank slope caused by the occasional rainfall during the sudder drop of the reservoir water level will cause the reser- voir water level to rise sharply, leading to the over- topping of the reservoir water and causing huge dam- age to the surrounding environment.