Numerical Simulation Study on Settlement of Surrounding Soil Caused by Sink Construction in Soft Ground Layer

Abstract

Sink construction is easy to trigger the surrounding surface settlement, which poses a hidden danger to road surface and buildings, and measures need to be taken to reduce the settlement. In this paper, through a sink operation of Nanniwan Power Tunnel Project, combined with numerical simulation and actual monitoring to study the impact of reinforcement treatment on surface settlement, and conduct model feasibility analysis. The results show that the surface settlement can be effectively controlled after rotary spray pile reinforcement, and it is more obvious with the increase of construction depth, the maximum settlement value is reduced by 40.2% after the first section is sunk, and 61.8% after all of them are sunk; the soil settlement after reinforcement shows a spoon-shaped change with the distance, and the in-situ soil shows a parabolic shape change. The settlement monitoring value of each point is greater than the theoretical value, the maximum is 5.3mm, 43.2% higher than the theoretical value; the minimum is 7.1mm, 9.2% higher than the theoretical value, which is within the permissible range of construction.