The influence of excavation of the dredged foundation of transmission towers on the stability of Yanzi landslide

Abstract

With the construction of the national network project, transmission towers are inevitably erected on the landslide body. Excavation of transmission tower foundation often causes disturbance to the soil of the slope and reduces the stability of the slope. At the same time, the unfavorable stacking of construction spoil is also an unfavorable load to the slope. Under the combination of various unfavorable factors, slope instability accidents are prone to occur, causing losses to the grid operation. In order to reduce the amount of excavation and to minimize the impact of foundation excavation on the landslide, generally, dredged foundation is the selected excavation method of the transmission tower foundation. Therefore, this article takes the Yanzi landslide and 500kV transmission tower as the research object. Firstly, the mechanical parameters of the soil of the Yanzi landslide were analyzed, and then the influence of the excavation of dredged foundation and the spoil pile loading on the stability of the landslide was studied by 2D finite element method. Finally, 3D finite element method was used for verification and supplementation. The results show that the foundation excavation of transmission tower has negligible effect on total landslide stability, but local potential landslides need to be considered.