Abstract:The research on the shallow depth excavation tunnel which is under crossed Wei bridge of line 2, 208 bid section of Dalian metro is carried out to analyze the vibration response to the structures including lining、bridge and pier, and the wave propagation law、attenuation characteristics in formation by three dimensional finite element, so that can prevent the blasting construction of stratum and the surrounding both structures caused by excessive deformation and damage. The results show that close to the blasting area, the vibration velocity of the blasting seismic wave peak’ attenuation rate is greater than the critical source area, at the same time attenuation rate is greater than the horizontal direction along the depth direction. The blasting seismic wave’s peak velocity will appear twice or more times in the structure, so that the blasting shock wave has strong multiple reflection and destructive to the structure. Displayed in the different depth of fixed-point monitoring, the velocity reached peak time and size are different, closer to the source, the greater peak of disturbed, and shorter time. Close blasting will have a great influence of the safety of existing tunnel lining, the blasting side of the arch waist, the vibration velocity is the most and need to focus on prevention in site construction.