Analysis of Influence of Curved Shield Tunnel Undercrossing Construction
About the author:
1. Construction Branch, Ningbo Rail Transit Group Co., Ltd., Ningbo, Zhejiang 315101, China;2. School of Civil & Environmental Engineering and Geography Science, Ningbo University,Ningbo, Zhejiang 315211, China
Abstract:
Based on the engineering example of a curve shield tunnel of Ningbo Subway Line 6undercrossing an existing subway station, three?dimensional numerical simulation was carried out basedon Midas GTS NX software, the whole construction process of tunnel undercrossing was simulated, anddeformation characteristics of the upper station floor, tunnel structure and ground surface were analyzed.Based on the numerical calculation results, the construction safety of curve shield tunnel undercrossing isevaluated, and the deformation control measures are put forward. The research results show that duringthe curve shield tunnel construction, the ground loss caused by the ove excavation of the inner side isgreater,which has a superimposed impact on the settlement of the station floor, and the maximumsettlement of the station floor is located at the center of the double?line tunnel when the tunnel excavationis completed. When the excavation of the left line tunnel is completed, the vertical convergencedeformation is smaller in the middle and larger on both sides, the construction influence of the righttunnel on the vertical convergence deformation of the left tunnel is smaller. The surface settlement causedby the undercrossing construction by the curve shield tunnel is mainly concentrated within 25m away fromthe center of the double?line tunnel. By taking necessary deformation control measures, the structuredeformation can be kept within the safe range.
