Study On Construction Blasting Vibration Influence And Partition In Railway Interchange Tunnel

Abstract:Along with the sustained and rapid development of economy in our country, the total demand for transportation infrastructure continues to grow. A great deal of new high-speed rail or high-speed project engineering appears adjacent to both rail or road that already built, it become inevitable that the new tunnel across the old ones with a small distance, form the interchange tunnel. When using mining method to build such kind of tunnels, it’s obviously that interaction of each other will be existence in blasting process. Therefore, to analysis the dynamic effects of the existing tunnel structure suffered, and then propose effective discriminant standard to control the security in blasting process and reasonable partition of interchange tunnel are of great significance.In this paper, under the basis of Natural Science Foundation of China, takes the Dandong Jinjiangshan interchange tunnel as the engineering background, using the theory of wave mechanics, dynamic strength theory and numerical simulation method, synthetically analyzed the dynamic response of both tunnels and seismic wave propagation medium under blasting vibration of interchange tunnel, put forward safety discriminant standard and criterion to interchange tunnels, and established the factors and partition of interchange tunnel blasting vibration influence. The main contents are as follows:(1) Investigated the cross tunnel blasting mechanism and seismic wave propagation law between the two media, combined with the application of theory of wave mechanics in cross tunnel, determined the blasting vibration partition influencing factors.(2) Using dynamic strength theory established the vibration speed to be the criteria of interchange tunnel blasting vibration impact, relying on the engineering practice, synthetically using numerical simulation criterion and the engineering experience analogy criterion, identified Blasting Vibration Safety Criterion(threshold).(3) Relying on the engineering example, designed similar conditions of new tunnel under the existing line in different spacing, different cross angles and different level of surrounding rock, numerically simulated blasting vibration, got the interchange tunnel blasting vibration response laws featured with vibration velocity of vertical direction and the maximum principal stress.(4) Established partition standard under the basis of interchange tunnel blasting safety criterion(threshold), evaluated the factors and degrees of the impact combined with theory and numerical simulation methods, determined the blasting vibration influence degree and expression of influence partition.(5) According to the blasting vibration effect and impact partition standard, using the method of statistical mechanics, get blasting vibration influence partition based on blasting vibration velocity criteria, and the partition use geometric proximity (A) and cross angles (θ) as variable quantity.There are65pictures、38tables and79references in this paper.