Numerical simulation analysis and mechanism study of soil cave type ground subsidence

Ten cases of ground subsidence in the study area are taken as the research object. Based on field investigations and combined with the geological environment conditions and engineering geological data of the study area, the basic geological background and ground subsidence development conditions of the study area are obtained. Several types of ground subsidence in the study area are comprehensively summarized, and the causes, spatiotemporal distribution characteristics, and collapse formation mechanisms of different types of ground subsidence are analyzed. The finite difference software FLAC3D was used to simulate the development process of ground collapse under tunnel excavation, building houses, groundwater level rise, and heavy rainfall conditions. The formation mechanism of ground collapse in the study area was obtained by analyzing the stress and strain inside the soil layer, as well as the displacement of the surrounding soil and surface of the tunnel. The research results indicate that the construction of residential buildings increases the overlying load, and the rise of groundwater level causes deformation of the soil around the cavern, leading to the expansion of the cavern. Under the influence of seasonal heavy rainfall, the surface undergoes significant settlement.