Influence of Undercrossing Construction of Metro Interval Tunnel with Mining Method on Bridge Group and Its Construction Control
DAI Weida;Beijing MTR Construction Administration Corporation;
Taking the interval tunnel construction between Yingbin road station and Sangong station undercrossing bridge group in Urumqi Metro Line No. 1 as the engineering background,a three-dimensional computational model of tunnel-stratum-bridge group was established by using FLAC 3D and the influence of undercrossing construction on the bridge group was analyzed. The results show that the horizontal displacement of the tunnel side wall is slightly larger than vertical displacement of vault,the maximum displacement of tunnel initial support is 14. 8 mm,the maximum vertical displacement of highway bridge and railway bridge is 2. 73 mm and 2. 1 mm separately,the initial support of the tunnel is in a safe state,and the tunnel construction has little influence on the bridge group. Based on this analysis results,four main control measures of undercrossing construction including the trial excavation before undercrossing the bridge group,control of strata deformation,emergency measures formulation and advanced geological forecast were put forward and the monitoring results of undercrossing section don't exceed the deformation control standard given by the test and evaluation unit.
【CateGory Index】： U231.3;U455.4