Abstract: To explore the influence of differential lateral foundation stiffness on the immersed tunnel, a case study is conducted on the immersed tunnel project between Chebei road station and Xinjiao east road station in Guangzhou. A threedimensional finite element model incorporating damage is established using load-structure method to analyze the settlement and segment damage of immersed tunnel under different lateral foundation stiffness. The results show that the maximum deformation is 11.6 mm in case of uniform distributed lateral foundation stiffness. It is revealed that: (1) The differential lateral foundation stiffness will induce differential settlement in adjacent segment joints. (2) The distribution pattern of lateral foundation stiffness will affect the settlement along the tunnel axis, the maximum differential settlement caused by the differential lateral foundation stiffness occurs at the joint between E22 and E3, and the differential settlement of the joint under segmented distribution pattern is greater than that under linear distribution pattern. (3) The continuity and uniformity of the lateral foundation stiffness can affect damage of concrete remarkably. The damage of concrete is mainly distributed in the area of the roof and bottom plate of the immersed tube near the middle wall, as well as the twochamber floor. The latter is more sensitive to the change of the lateral foundation stiffness. Thus, some measures should be adopted to ensure its safety.

Key words: immersed tunnel, differential settlement, numerical calculation, lateral foundation stiffness, immersed tunnel damage