Study On The Blasting Vibration Control Technology Of Neighborhood Highway Tunnel

The neigbourhood tunnels are featured as less land-covering,cost-saving and attractive in appearance, compared to separate tunnels and arch tunnels, but high complexity in construction and technical requirements. At present, researches on neigbourhood tunnels have been fully unfolded, but in an exploratory stage, without uniform understandings and conclusions. So it has both theoretical and practical significance to carry out the systematic study of neighborhood tunnels.This paper studies 3 representative tunnels on the Huang Qu Nan Expressway in Zhejiang province, basing on their locations and lithological characteristics, and focuses on the impact caused by the blasting viabraton. It takes numerical simulation and on-site blasting vibration monitoring as the main studying means and aid, respectively. Those two methods are compared and analyzed with each other to get a reasonable result. Seismic waves are studied by the finite element analyzing software LS-DYNA. This paper starts with the velocity spreading field of seismic waves, analyzes the viabration velocity of critical points in neigbourhood tunnels with different rock grade, then criterion of rock stability obtained. It analyzes the disturbed areas of surrounding rock, due to the conventional blasting method, studies the vibration characteristics and variations of middle rock pillar. The possibility of using this calculation method to analyze the viabration intensity is proved by comparasion of monitoring results and calculation figures. This paper elaborates the theoretical mechanism of rock blasting, assesses its applicability; gives a brief introduction to the blasting theory, and clarifies the mechanism,types and characteristics of seismic waves.The main comtent of this dissertation are as follows:1. To determine the reasonable minimum spacing of neigbourhood tunnels in different grade where blasting viabration is applied;2. To analyze the mechanical characteristics of neigbourhood tunnels affected by blasting vibration, by using numerical simulation methods;3. The calculating results are are checked by the comparative analysis to the on-site viabration monitoring. Adjustments are carried out as required and revised viabration monitoring methods are proposed.