School of Civil Engneering, Chongqing University
the Chongqing Construction Science and Technology Plan Project (No. 2019-0045), and the Fundamental Research Funds for the Central Universities (Grant ID 2019CDJDTM0007) and the Graduate Research and Innovation Foundation of Chongqing, China (Grant No. CYS18024).
Parallel tunnels are generally constructed in urban subway to facilitate the traffic in the modern cities. Common solutions for predicting settlements induced by two parallel tunnel excavations are based on single tunnel case and utilizes the simplified superposition method to generate the deformation profile without considering the interaction between two tunnels. In this study, the transparent soil model tests are performed to visualize the surface and subsurface settlements induced by the excavation of two parallel tunnels in sandy grounds. Several key influential factors are investigated, including the spacing between the two tunnels, the volume of ground loss and the buried depth on parallel-tunnel interaction as well as the surface and subsurface settlements. Then the relationship between volume ground loss and the settlements is built up. It is hoped that this study can provide guidelines for design and construction of urban parallel tunnel excavations.