Study on the Influence of Blasting Vibration in the Crossing Section of Headrace Tunnel on the Existing Railway Tunnel
In view of the impact of cross tunnel blasting construction on the safety operation of the existing tunnel,based on the new Ruiyang diversion tunnel,this paper adopts theoretical calculation to check the vibration safety,to ensure that the vibration generated by drilling and blasting construction is controlled within the established standard,and further combines the finite difference dynamic analysis method.The particle vibration velocity and stress distribution of different parts of the existing tunnel structure in the process of underpass construction are studied.Finally,the theo-retical analysis and numerical simulation results are verified and analyzed according to the engineering monitoring data.The results show that the blasting construction of the new tunnel will not threaten the safety of the existing structure.The vibration response of the existing tunnel is closely related to the position of the explosion source.When the explo-sion source is located at the crossing point,the vibration velocity of the existing lining reaches a peak of 4.43 cm/s.The peak vibration velocity of the same characteristic part decays from the maximum peak fault to both sides,and the atten-uation is faster at the far explosion source side.The vibration effect of blasting excavation on the excavated area in the rear is slightly greater than that of the unexcavated area in the front.The distribution law of vibration velocity obtained by field vibration monitoring is consistent with the numerical simulation results.The maximum vibration velocity values measured are all lower than the safety control standard.The research results can provide reference for vibration safety control of similar upper and lower cross tunnel projects.
upper and lower cross tunneldrilling and blasting constructiondynamic analysisvibration characteris-ticssafe threshold
万方数据
维普
