抗滑桩加固边坡稳定性3维极限上限拓展分析

The technique of anti-slide pile is widely applied in practical engineering as a common measure of slope reinforcement. The slope stability analysis considering its effects is of high theoretical and practical significance. Based on the upper-bound limit analysis method, 3D rotational failure mechanisms are extended by introducing new geometric parameters. The calculation framework of safety factor is established considering the equation of internal dissipation and external work rate. The minimum upper-bound solution of safety factor and the most dangerous failure mechanism are calculated through optimization procedure. Parametric studies were carried out to investigate the effects of pile location, pile spacing, slope angle, slope width on the geometry of failure mechanism and the stability of a slope reinforced with piles. The geometry of failure mechanisms is also discussed. The results demonstrate that the most effective location of the anti-slide piles is between the middle and top of the slope, which is not influenced by the slope width. With a relatively smaller slope width and a pile location close to the slope toe, the critical failure surface passes through the slope face. The farther the pile location is away from the slope toe, the closer the failure surface is to the slope face and the greater its curvature. For slopes with small pile spacing, a secondary slope failure tends to occur above the pile location. Furthermore, the safety factor of slope decreases with the increase of pile spacing. The greater the slope width is, the lower the safety factor is and the closer it is to that of a 2D slope. The failure partbecomes thicker as the pile space and the slope width turns larger. While the slope angle is small, the critical failure surface passes below the slope toe and through the slope base. Obviously the extension of failure mechanism leads to additional optimization of the results.