Model test of anti-slide pile with micro-crack repaired by prestressed anchor cables

Application of prestressed anchor cables is one of the most important methods to repair anti-slide piles with micro-cracks. This paper examines the anti-slide pile with micro-crack repaired by prestressed anchor cables by using of the large physical model test, to discuss the feasibility of anti-slide pile repair and to obtain the characteristics of deformation and failure during the repair engineering. Test results show that (1) application of prestress anchor cables can improve the bearing capacity of piles with micro-cracks; (2) the characteristic curve of pile top displacement under the landslide loading can be divided into three stages, i.e., the stage of compaction, elastic deformation and failure; (3) failure occurs in the pile near the location of the sliding surface under the landslide loading, and this failure is sudden, and tension failure occurs in the pile at the location of the anchor hole under the anchor cable prestress, meanwhile, cracks extend at the location of the sliding surface. The soil pressure presents triangular distribution under the landslide loading and inverted trapezoidal distribution under the anchor cable prestress, and the earth pressure peak is transferred from the sliding surface to the pile top. Prestress applied to piles lowers the value of the maximum bending moment, but the position of the maximum bending moment transfers to the anchor hole position and the position near the sliding surface, thus the two positions are the weak part of the pile by using of the prestressed anchor cables to repair the pile with micro-crack. The research results are of guiding significance for the popularization and application of anti-slide pile with micro-cracks repaired with prestressed anchor cables and the design of anti-slide pile repairing projects.