Study On The Stability Of High Fill Embankment Based On Slip-line Theory

The action of weight, rainfall, and external load, could lead to the emergence of a variety of different forms of destroying of high embankment. Study on stability of high fill embankment can effectively control filling failure to avoid unnecessary economic losses. In this thesis, the stability of the high embankment under different working conditions was studied by the aid of Abqaus and Matlab program of slip-line field.Firstly, a lot of literature survey on the theory of slip line field was made in this thesis, and the basic principle of slip-line field theory was described.Afterwards, the basic law of high embankment stability under different working conditions was explored, by using the slip-line field theory for the first time. The results show that high embankment under the condition of three steps, the third step height increase led to the safety coefficient of embankment increased. The first step and the third step slope were unchanged, the second step slope was slowed, which led to the safety coefficient of embankment increased. Under different conditions of replacement-soil and unreplacement-soil strength parameters, the safety factor increased with the increase of internal friction angle and cohesion. however, the increasing trend was slowed down. When the internal friction angle increased to 30°, the cohesion increased up to 30 k Pa. The effect on plastic zone and the location of the critical slip surface gradually weakened, and the internal friction angle greater impact on the plastic zone. According to the change trend of the critical slip and the minimum safety factor, the cohesion of the filling soil should be greater than 20 k Pa, the internal friction angle of the filling soil should be greater than 20 °.Finally, a typical high fill embankment was selected as a case study on the Guang-Fo-Zhao highway. The safety coefficient and the change trend of critical slip surface were comparatively analyzed between the model of replacement and unreplacement. The results show that the embankment safety coefficient of the replacement was greatly improved, and it was more than 1.300. In addition, the critical slip surface gradually moved up, the soil sliding range gradually decreased. An economic safety of step height combination design was proposed, which provide a basis for the origin design.