Influence of Under-pass Blasting Construction of Diversion Tunnels on Highway Tunnel Structures:Taking Xishan Tunnel Project in Ouhai District,Wenzhou City as an Example
In order to explore the response law of lining under blasting vibration and the stress distribution state under blasting load when the blasting source gradually approaches the existing tunnel,combined with the Xishan Tunnel Project in Ouhai District,Wenzhou City,the safety of intersecting tunnels during the construction of new tunnel blasting was studied based on the blasting monitoring data and numerical simulation results at the construction site.The research findings indicate that vibration velocity is primarily influenced by the distance to the blasting center and the amount of explosive charge used.Specifically,as the blasting center distance decreases and the amount of explosive charge increases,the peak vibration velocity becomes higher.The blasting center distance determines the location of the peak lining speed within the tunnel.Simultaneously,this peak speed location corresponds to the point of maximum tensile stress.As the blasting center distance decreases,the critical point shifts from the arch waist position to the foot of the arch.