Abstract:
The composite structure of anti-slide pile and anchor cable can give full play to the rigid constraint of anti-slide pile and the active tension of anchor cable to control slope deformation, showing good seismic performance, and has been widely used in landslide prevention in strong earthquake areas. However, at present, there is little research on the seismic dynamic response of slope strengthened by pile-anchor composite structure, and its cooperative seismic mechanism is not clear. Based on Newmark model, this paper presents a dynamic response analysis method of slope strengthened by pile-anchor composite structure considering earthquake time-history characteristics. The method is applied to the high slope of Shandong expressway, and the permanent displacement, safety factor and internal force of supporting structure of the slope with different reinforcement methods are analyzed. The results show that the pile-anchor composite structure effectively reduces the permanent displacement of the slope and ensures the stability of the slope. Compared with only anchor support and only pile support, the maximum anchorage tension at the anchorage end, the maximum shear force and the maximum bending moment of the pile body are reduced. With the increase of cohesion and internal friction angle, the yield acceleration of slope increases in direct proportion, while the permanent displacement transitions from sharp decrease to slow decrease, in which the influence of cohesion is more significant. By forming an active stress system, the pile-anchor composite structure increases the yield acceleration of the slope, realizes the coordinated stress of the pile and the anchor cable, and prevents excessive stress concentration near the sliding surface, which is an efficient reinforcement method.