Abstract: The combined action of soil and structure should be effectively considered when it is applied to the structural analysis of shield tunnel lining. Based on the composition system and loading method of the continuum model, a numerical simulation model considering the interaction between soil and tunnel, rotation stiffness nonlinearity of segment joint, and 3D assembly effect of lining is established, and the calculation results coincide with the test results well. and the numerical results matched well with the test results. A parametric analysis is conducted on the lateral pressure coefficient and soil stiffness. The results show the following. (1) With the decrease of lateral pressure coefficient and soil stiffness, the ovalisation deformation of lining and the bending moment of the lining crown increase. The ovalisation deformation of the lining is dominated by the relative rotation of longitudinal joints. (2) The high stress area of the soil changes from the crescent shape at the crown to the uniform distribution around the circumference as the lateral pressure coefficient increases, and the low stress area at haunch gradually disappears, while the ovalisation deformation of the tunnel tends to be 0. (3) The soil stiffness has less effect on the stress distribution of the surrounding soil, whereas the circumferential stress conditions is significantly improved with the increase of the soil stiffness, and the ovalisation load on the crown also has a trend towards circumferentially uniform.

Key words: shield tunnel, combined action, joint nonlinearity, continuum model, lateral pressure coefficient, soil stiffness