Study On Losing Stability Mechanics Of Counter-Tilt Rock Slopes

Counter-tilt slopes are those with anti-direction terranes, in other word, the slant of slope is opposite to that of the terrane. Deformation and failure of the counter-tilt slope are mainly effected by the terranes. However, most previous investigations are focus on the same-tilt slopes, and only a few works have been done to study deformation mechanics and failure mode of the counter-tilt slopes. So, it is great important for design and stability evaluation of slopes to study deformation mechanics and analysis methods of counter-tilt slopes.Laboratory physical model test is an important approach for study on stability and failure mechanics of slopes. In allusion to a certain slope in Guangdong segment of Jingzhu Expressway, several groups of physical model tests are performed, and the factors effecting stability of slope are analyzed. The results show that the stability of counter-tilt slopes don't rests with terrane obliquity but strength and thickness of terrane interface, which provides guide for design and research of slopes. It is also found that the deformation value of the slope is very little during the first phase after being excavated, and then the deformation will accelerate largely. The time span changes with different structures of rock slopes. Compared with the failure character of the real slope, it is feasible to reinforce the slope according as tilting failure mode.Finite element method can deal with complex boundary conditions, inhomogeneity and anisotropy of rock material. It can also simulate the unlinear stress-strain relationships of materials. According to the stress and deformation fields of surrounding rock mass, potential failure position may be obtained and the mechanics properties of rock material can be comprehended. In this dissertation, the characteristics of slope displacement and the effects of terrane obliquity on deformation have been investigated using finite element method. By comparing the results of numerical simulation and field tests, it is pointed out that the obliquity of terrane has little effect on the slope deformation and that the reinforcement design method of slopes is reasonable.