Research on Crack Propagation Law of Concentrated Energy Blasting in High Ground Stress Tunnel
As the depth of the rock mass increases,the impact of the high ground stress environment on tunnel and underground engineering blasting construction is also increasing.However,the high ground stress conditions and the energy generated by blasting of explosives have not been fully utilized.Therefore,studying the mechanism of crack propagation in tunnel blasting under high ground stress and efficient energy utilization control methods is of great guiding significance for saving construction costs.This article theoretically studied the static distribution characteristics and dynamic evolution law of high ground stress in tunnels.Numerical simulation analysis was conducted on single hole and double hole concentrated energy blasting under high ground stress.It was found that the length of the main crack decays exponentially with the increase of stress value and increases linearly with the increase of lateral pressure coefficient.When the maximum principal stress reaches 40 MPa,as the angle between the direction of energy accumulation and the direction of maximum principal stress increases,the permeability of inter hole cracks gradually deteriorates.The energy gathering tube device is applied on site to complete energy gathering blasting.The on-site vibration velocity data is monitored through blasting vibration meter to evaluate the effect of energy gathering blasting by comparing the peak vibration velocity in conventional drilling and blasting methods,which provides reference for subsequent engineering applications.
万方数据
维普
