Analysis on stability of ecologically restored slope in Qianlingshan, Beijing

The analysis on high-steep rocky slope stability is a research focus for a long time, because it is considered as the reason why geological disasters occurres, such as slope instability and landslide. Ecological restoration of slope is an urgent issue that can improve environment but may reduce the stability of the whole slope system in some extent. The stability of the ecological slope in Qianlingshan, west suburb of Beijing is analyzed with nonlinear FEM strength reduction method. The interpretation of geological penetrating radar surveying refers to that the rock slope consists of isotropic limestone without obvious fault. The numerical modeling is based on the parameters by rock mechanical experiment, combined with the internal structure of rock mass measured by geological penetrating radar. The safety factors and plastic area distribution and deformation contours are obtained under different load conditions. The result shows that the safety factors are 17 and 12.5 and 5 and 2 respectively on dry natural slope, dry ecologically-restored slope and saturated natural slope as well as saturated ecologically-restored slope. And that the deformation of slope are biggest on the foot of slope and the middle and lower parts of ecological band, the potential sliding surface mainly extends towards the top of slope along the plane of 45° dip angle. Thus, the basal slope and the middle and lower parts of the ecologic zone are the major reinforcement places and the reinforcement measure should be anchor rod fixation and effective water drainage.