Research on the Collapse Law of Tunnel Surrounded with Fracture Rock under Blasting Load

To study the collapse law of tunnel surrounded with fracture rock under blasting load, this paper simulates the collapse process of fracture surrounding rock while the tunnel suffers blasting excavation by virtue of discrete element method software UDEC relying on Beigu Mountain Tunnel engineering in Lianyungang. This research reveals the changing rule of factors including displacement, velocity and acceleration while the crack surrounding rock falling down. Furthermore, it explores collapse and failure pattern of fracture surrounding rock with different joints. In this way, this research can provide reference for similar tunnel construction. The results illustrate that: The fracture surrounding rock rises a little and then falls when it is exposed to explosion. The landslide motion is mainly divided into deformation and slip as the joint inclination varies. When the 45-inclination-angle joint combines with another different inclination-angle joint, the rock mass reflection can be concluded as deformation, cracking and falling.