Analysis of monitoring and treatment effect of anti-sliping piles for the landslide at Jiangdingya, Zhouqu County

In order to study the bearing characteristics and treatment effects of anti-sliping piles in the treatment of accumulation landslides in the Bailong River Basin, Zhouqu section, Zhouqu Jiangdingya landslide treatment project was taken as the object. Steel bar stress gauges were arranged at the middle and corners of the upstream and downstream sliding surfaces of the three anti-sliping piles at the front edge of the landslide, and dynamic data from three years were obtained on site. Numerical simulation analysis was conducted on the treated landslide using ABAQUS. The results show that: (1) The stress growth rate of pile reinforcement has significantly slowed down compared to the end of construction, which is lower than the design value of tensile strength, and the rebar is still in an elastic working state, indicating that the treatment effect of anti-sliding piles on the landslide control is good; (2) The multi-level sliding of Jiangdingya landslide causes the anti-sliding piles to not only be effected by the landslide thrust, but also by the frictional force of the rock and soil body. Specifically, the steel bars on both sides of the sliding and backing surfaces of the three test piles is mainly tensile stress at depths of 5 m, 10 m and 20 m, which is opposite to the stress state of tension and compression on both sides of the section when designing anti-sliding piles according to current standards. This discrepancy is due to the superposition effect of stress. When the tensile stress generated by friction force on the pile is greater than the bending compressive stress, the overall stress of the steel bar on that side will be tensile stress. (3) After the completion of the treatment project, the horizontal displacement of the landslide is analyzed by numerical simulation. It was found that the maximum horizontal displacement of the landslide was 33.93 mm, indicating that the reinforcement of the landslide support structure is good. The landslide body is in a stable state after reinforcement, and a new deformation coordination between piles and soil has been formed. The research results can provide scientific basis for the design of accumulation landslide control project in this area.