Experimental Study on the Soil–Structure Responses Induced by Tunnelling in Limited Space

Abstract

As the economy develops rapidly, newly built tunnels in congested urban areas are becoming more and more common. Based on similarity theory, this study conducted a laboratory model test to investigate the soil–structure responses induced by the construction of a new tunnel in limited space which was formed by the existing underground infrastructures. The soil movement, convergence of the tunnel and distribution of the soil stress were explored. The test results revealed that the limited space could have a significant shielding effect on the soil movement. The maximum ground subsidence and the range of ground settlement induced by the construction of the tunnel in limited space were 60% and 40%, respectively, smaller than those induced by the construction of a tunnel at a “greenfield” site. The deformation of the tunnel was also restrained distinctly. Moreover, a soil settlement trough appeared below the bottom slab of the underground structure. The findings can shed some light on the surrounding responses induced by tunnelling in limited space in soft clay and can offer the valuable guidance for the similar projects.