Study On Rock Burst Released Technology In Underground Caverns

Under high geostress condition,Rock burst as an engineering geological phenomena encountered frequently during the excavation in underground caverns,has caused a huge impact on normal construction of underground engineering and produced seriously threatens to the safety of the construction person.At present,as an active measures,pile the stress released hole in advanced surface has been widely applied to the engineering practice.But for the existing apply situation,there is a certain blindness in the hole design.Therefore,to explore the optimal placement of the stress released hole in different stress condition caused a strong guiding significance to the engineering practice.Rock burst may occur in different area in disparate ratio of the horizontal stress and the vertical stress(lateral pressure coefficient).This article uses the finite element numerical analysis software MIDAS GTS,by choosing the reasonable model parameters and boundary conditions,numerical simulate the commonly used stress released method in different lateral pressure coefficient.Although rock burst is a dynamic phenomenon,its inoculation is a static process.This article analysis the secondary stress distribution in caverns,based on the rock burst strength criterion,determine the rock burst most possible happened area.Statistic and analysis the effects of the different surface released hole in the rock burst most possible happened area,and make a research on the optimal placement of the surface stress released hole,some qualitative and quantitative conclusions can be obtained,Mainly as follows:(1)Use the finite element numerical analysis software to numerical simulate the four commonly used stress released method in lateral pressure coefficient 2?1.5?1?0.8?0.5,and evaluate the released effect of the stress released hole in the rock burst most possible happened area.Draw a conclusion that the effective reduce range is less than 0.5m by a 0.2m diameter stress released hole,and the stress biggest drop mostly happens in 0.1-0.25m distance to the hole boundary.(2)By contrast and analysis the stress released scope of the hole in different punching depth,reach a conclusion that the different punching depth which meet the punching requirements has little effect on the internal prerelease performance of the surrounding rock.At the same time,in different lateral pressure coefficient,give out the stress reduced scope and the stress wave range along the deep direction in the rock burst most possible happened area.In addition,come to a law of the conclusion.Finally,composite the released effect of the commonly used pattern hole in different lateral pressure coefficient,draw the application situation of the four commonly used methods.(3)Composite the entire hole released effect in small region of the rock burst most possible happened area in different lateral pressure coefficient,conclude the more superior layout program of the surface stress released hole.(4)Based on the existing conclusions,put forward some engineering suggestions to the stress released technology in underground caverns.