Study On The Influence Of Deformation And Stability Caused By Water Level Depression In Slope

The seepage field and the seepage force caused by the water level depression are the two significant factors affecting the surface deformation and the stability of slope. Although the coupling of seepage and stress field comes to be true with the development of the computer technology, few researches on the influence of deformation and stability at home and board can be available produced by the seepage under the condition of water level depression at present. Aiming at the problems brought by the water level depression in slope during the excavation course of the slope foot, using the finite element software — Plaxis the paper has detail calculation and analysis on the deformation and the stability of slope considered the effect of seepage, combining with the predecessor theoretics on seepage deformation and slope stability. Besides, there are several groups of comparison and analysis on stress and deformation of soil masses and retaining wall under the different hydraulic gradient and make a rational result. The main works and results of the paper are listed as the following:(1) Based on the effective stress theory and the deformation mechanism of soil, the paper founds the model of the excavation at slope foot, and stimulates the condition of the change of the effective stress and deformation at the different excavation stage with the seepage field and without the seepage field. What's more, the comparative analysis is made at the two different conditions. It is stated that the effective stress is increased by the hydraulic stress, which leads to the large vertical deformation behind the excavation solid. And the shearing stress and moments are improved on the condition of the seepage and the position of the extremum descends.(2) The influence of the groundwater seepage on soil mass comes to be true through the seepage force (the dynamic stress) on the soil grain. According to the formula of the seepage force, it can be deduced that the seepage force only lies on the hydraulic gradient. Found the model and analysis the deformation condition with the different hydraulic gradient. And it displays that the bitter hydraulic gradient, the bigger seepage force, the higher value of the effective stress and the acuter deformation, as well as the shearing force and moments of the retaining wall. Besides, the increment shearing stress and moments becomes higher with the increment improving of the hydraulic gradient.(3) The downslide force can be increased with the seepage force in slope mass as the seepage, which has a bad effect on the stability of slope. The paper simulates the stability of slope considering the seepage and without it by the finite element softwareand evaluates quantificationally the effect degree of the seepage on the stability of slope. And it is found that the seepage can decrease the safety factor of slope and the stability, which have the inverse ratio relation to the hydraulic gradient.(4) A solid model to validate the results and prove the rationality of the result and the engineering applicability of this finite element.