Study On The Dynamic Response Of Blast Loading Force On Crossing Tunnel

At present,China’s transportation construction has entered a stage of rapid development.Railway,highway lines gradually form networks.Old and new lines cross are very frequent.There are many cross constructions of the tunnel.Limited to the current level of tunnel construction,the traditional blasting excavation in mountain tunnel construction is still very common.Blasting always cause a huge impact on the surrounding environment.Therefore,in cross tunnel constructions,the blasting impact on both tunnels is a problem that people are very attention in recent years.This paper mainly studied the response of both the tunnel under blasting vibration,and the blasting vibration safety margin.Firstly,this paper simplified the blasting load under the condition of normal blasting method with different surrounding rocks.And analyzed the blasting vibration velocity,displacement and stress of the existed tunnel under the blasting vibration from excavation of a new tunnel.The response law of each part of the existing tunnel under the different blasting positions of the new tunnel is determined.Secondly,this paper discussed the tunnel blasting safety standards,and determined the impact of different safety vibration velocity standard.Finally,take vibrating velocity as the evaluation standard,and make a quantitative classification of different influence scope of existed tunnel under the blasting vibration on the condition of different distance,different surrounding rock grade.