| Dynamic response during the small spacing tunnels blasting excavation is a very important research project, which is very important to control blasting vibration, to decrease the disturbance to tunnel surrounding rock, the lining of neighboring tunnel and the ground buildings, because of blasting seismic wave. In this paper, it's expounded at firstly that the general situation of small spacing tunnels development and some concerned methods of numerical analysis and their research actuality and information. And then that the propagation mechanism and the characteristics of blasting seismic wave are analyzed. Based upon analysis of the characteristics of district weak stress site in demolition, the frequency and amplitude characteristics of particle vibration velocity and the dynamic response characteristics of neighboring tunnel are discussed. At the same time, much blasting vibration monitoring data has been collected in Linchang Tunnel engineering, that the peak particles velocity (PPV) and distribution of the main vibration frequency are analyzed and discussed combined with the blasting vibration monitoring data of the 2nd term engineering of WuTongShan Tunnel. And that the transect locality of the maximum PPV and locality of the maximum PPV at the same section Are ascertained lastly.In this paper, numerical simulation model is built based on the engineering analysis software ANSYS/LSDYNA, to calculate and analyze the construction process of small spacing tunnel during blasting excavation. Founded on numerical simulation results, dynamic response characteristics of neighboring tunnel effected on blasting seismic wave is studied through analysis of stress wave propagation in rock mass and influence of neighboring tunnel's structure stability. At last, that the results of numerical simulation is validated through comparing with situ test data in tunneling, and it is confirmed that the PPV calculated is nearly equivalent to the results of situ blasting vibration monitoring.
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