| In the current urban rail transit project in the vigorous development of the community,due to the needs of the site environment or line selection,it has been a common phenomenon in the actual construction of the tunnel encountered in the parallel operation and tunnel overlap situation,the new tunnel or tunnel group on the existing tunnel or other structure of the interaction problem has become very prominent!Due to the limitation of the construction site,the construction unit in the single-channel multi-operation plane at the same time the construction of parallel small clearance,it becomes very cautious and difficult problems about the construction process arrangements,reasonable cross-section construction distance to determine the construction safety assurance,tunnel support structure by follow-up construction blasting vibration Influence,reasonable timing and so on.This paper combines the Chongqing Rail Transit Line 10 project,carried out a detailed investigation on the actual project,using theoretical analysis,numerical simulation method for systematic research,and then combined with the measured data collaborative analysis and simulation results were compared,draw the following main conclusions:(1)The influence law of vibration on adjacent tunnel when the NO.5 tunnel blasting excavation:the distance between the face of the No.5 tunnel and the face of the 7th and the 9th tunnel is not less than 40m and 30m,at this time,the distance between the No.5 tunnel and the adjacent tunnel surface is the best reasonable distance,it can ensure both the construction period and meet the safety requirements.(2)The influence law of vibration on adjacent tunnel when the NO7 tunnel blasting excavation:the distance between the face of the No.7 tunnel and the face of the 5th and the 9th tunnel is not less than 40m and 3 0m,at this time,the distance between the No.7 tunnel and the adjacent tunnel surface is the best reasonable distance,it can ensure both the construction period and meet the safety requirements.(3)The influence law of vibration on adjacent tunnel when the NO.9 tunnel blasting excavation:the distance between the face of the No.9 tunnel and the face of the 5th and the 7th tunnel is not less than 40m and 30m,at this time,the distance between the No.5 tunnel and the adjacent tunnel surface is the best reasonable distance,it can ensure both the construction period and meet the safety requirements.(4)When the No.5 tunnel blasting excavation,the analysis of the combined vibration velocity of the vertical vault lining of No.5 tunnel shows that,the reasonable distance for the construction of the No.5 tunnel secondary lining is the distance between the explosion source and the mass point in the tunnel dome lining is greater than or equal to 46 meters.(5)When the No.7 tunnel blasting excavation,the analysis of the combined vibration velocity of the vertical vault lining of No.7 tunnel shows that,the reasonable distance for the construction of the No.7 tunnel secondary lining is the distance between the explosion source and the mass point in the tunnel dome lining is greater than or equal to 32 meters.(6)When the No.9 tunnel blasting excavation,the analysis of the combined vibration velocity of the vertical vault lining of No.9 tunnel shows that,the reasonable distance for the construction of the No.9 tunnel secondary lining is the distance between the explosion source and the mass point in the tunnel dome lining is greater than or equal to 46 meters. |
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