The damage and vibration characteristics of mountain tunnel surrounding rock under the influence of reserved core soil blasting method are studied to provide theoretical reference for blasting parameter optimization and tunnel reinforcement design.Based on the left tunnel project of Aktepu No.2 in Xinjiang,the numerical model of tunnel blasting excavation is established with ANSYS/LSDYNA software.The rationality of the numerical model is verified based on the actual excavation contour and vibration velocity monitoring data,and then the cumulative damage characteristics,vibration velocity distribution and attenuation law of surrounding rock are analyzed.After blasting,the outline of the tunnel is smooth,and the upper part of the reserved core soil is seriously damaged.The vibration velocity of tunnel arch vault in y direction,spandrel in z direction and arch foot in x direction is the largest.The closer the distance to the tunnel face,the greater the error of the vibration velocity predicted by Sadowski's empirical formula.In order to ensure the stability of the structure,before the next blasting construction,the explosive load can be reduced by reducing the cut hole,the auxiliary hole charge or adjusting the hole network parameters,and the emphasis is placed on strengthening along the direction of the maximum vibration velocity.In the application of Sadowski's empirical formula to predict the vibration velocity within 10 m from the tunnel face,it is important to avoid approximating the size of the burst center distance by the distance in the z direction alone.Instead,it is necessary to consider the distances in all three directions simultaneously.
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