Abstract:With the great development of the urban underground space, the intersecting position of the existing tunnel and new foundation pit usually leads to the discontinuity of the underground diaphragm wall, which leads to problems of groundwater seepage and insufficient retaining capacity. Taking the excavation project of a deep foundation pit in a metro station of Shanghai as an example, the composite retaining wall is constructed according to the artificial freezing method in order to achieve the dual effects of soil reinforcement and waterproof sealing. Combined with the finite element analysis method, the temperature distribution of soil around the tunnel is simulated and obtained. The field monitoring is carried out to study the stress and deformation characteristics of the "freezing method + underground diaphragm wall" composite retaining wall. The adverse effect of freezing method on the underground diaphragm wall is evaluated by calculating the bending moment. And the reinforcement requirements of wall body to resist the hogging moment are put forward.
