| The multi-arch tunnel has become a special form of tunnel structure due to its complex stress conditions and difficulty in structural analysis.The construction of double-arch tunnels in water-rich karst areas is even more difficult,and it is a challenge to the design and construction of tunnel engineering.Drilling and blasting is a common method for tunnel excavation.The complex,hidden and common blasting vibration hazards caused by blasting construction will inevitably affect the safety of double-arch tunnel construction.Therefore,the impact of blasting vibration on double-arch tunnels in water-rich karst areas is studied.This article introduces the current research status of tunnel blasting vibration at home and abroad,and systematically expounds the theory of seismic wave and blasting vibration,and takes the double-arch tunnel under the condition of soft surrounding rock in water-rich karst area as the research object,and explores the effect of blasting vibration on the tunnel.The impact is divided into the following aspects:(1)Based on Guiyang Metro Line 2 Huanzi Interval Tunnel,conduct blasting vibration test.Collecting the blasting vibration data of the double-arch tunnel,using the mathematical regression method to study the effect of the back hole blasting on the blasting vibration of the front hole blasting side,and get the K and α values in the Sadolfsky formula.(2)Using numerical simulation of the surrounding rock in water-rich karst areas,the impact of blasting of the trailing tunnel on the vibration of the leading tunnel,the partition wall and the ground surface,and analyzing the consistency of the measured data on the front side of the leading tunnel with the numerical simulation results.The simulation result analyzes the attenuation law of blasting vibration in this case,and finds out the position of each part that is most affected by the blasting construction.(3)Use the derived Sadowski formula relying on engineering geology to predict the maximum amount of charge in a specific situation,and optimize the blasting parameters.According to the obtained research rules,safety protection measures and anti-seismic measures for blasting operations are proposed. |
