Abstract: Underground structures affect the land subsidence by changing the groundwater seepage and soil deformation. Based on the direct shear test of the soil-concrete interface, this study analyzes the influence of soil composition and moisture content on the interface friction angle and cohesion. Combined with the constitutive model of the interface between the soil and the concrete, the hydraulic and mechanical coupled model was employed to simulate the land subsidence. The results show that the shear stressdisplacement curve of the interface exhibits strain hardening characteristics and conforms to a hyperbolic curve. The clay particle contents and moisture contents have clear effects on the interface shear strength parameters. With the width and insertion depth of the baffle increasing，the water-blocking effect enhances, inducing an increase in the maximum subsidence. Baffles in soils can block water flow and hinder the soil displacement at the same time, thus the maximum subsidence first increases and then
decreases with the increasing distance between the baffle and the pumping well. 

Key words: land subsidence, direct shearing test, interface surface model, diaphragm wall, numerical simulation