Abstract: Leakage is easy to occur in the operation of large-volume pressure box culvert, which has adverse effects on the surrounding environment. For example, water seepage affects the use of cultivated land, and the non-uniform settlement of soil leads to the destruction of box culvert and nearby structures. In order to study the influence of box culvert seepage on the displacement field and stress field of the surrounding soil, fluid-solid coupling method was used to calculate and analyze the development law of the mechanical properties of the soil around the box culvert after the leakage occurs under different leakage locations, permeability coefficients and water pressure. The analysis results show that the displacement settlement of soil around the leakage is the largest, and the effective stress around the leakage location decreases when the location of leakage was intersection of box culvert side wall and roof. After the proportion of soil permeability coefficient changes, the lifting height of soil mass at the bottom of the box culvert also increases, but the degree of soil uplift eventually reaches the limit. When the soil permeability coefficient changes in different proportions, the infiltration coefficient of the soil layer where the leakage was located increases, so that the soil settlement is larger and the height of the infiltration surface is higher. The larger the internal water pressure of the box culvert is, the larger the displacement settlement amplitude is and the larger the settlement range is.

Key words: geology, leakage, box culvert, fluid-solid coupling, displacement field