Abstract:With the further development of urban underground space, traffic tunnels, underground stations, underground shops and other buildings (structures) inevitably become more and more dense, so there is often a phenomenon of heaped load near existing tunnels. In this paper, the influence of heaped load on disturbance and deformation of existing pipe jacking tunnel is discussed through finite element calculation with Moore-Coulomb (M-C) constitutive model and the hardening constitutive model (HSS) considering the small strain characteristics of soil. The results show that under the same loading size and width, the influence range of the soil under HSS constitutive model is much lower than that under M-C constitutive model. When the loading size is 100 kPa, the influence range of the side and depth of M-C constitutive model reaches 75 m, while the influence range of the side and depth under HSS constitutive model is only 35 m and 30 m. When the loading width is 25 m, the side of M-C constitutive model is only 35 m and 30 m. The influence range of edge and depth is75 m, while that of HSS constitutive model is less than 35 m and that of side is less than 40 m. At the same time, based on the results of finite element analysis, the suggestion of forbidding loading directly above the existing tunnel is put forward.