Prediction And Prevention Research Of Rock-burst In Kuocangshan Long-tunnel

Kuocangshan extreme long-tunnel possesses the characteristics of deepcarving, extreme length and crossing complicated geological environment and tectonic stress field of highland so as to exist phenomenon of rock-burst. So rock-bust prediction and prevention measure that is very important in tunnel design and construction.There is neither a set of mature theory in use of prediction it nor systematic and comprehensive understanding its reasons because of complicated problems existing in the of rock-burst in sub engineering and many factors that influence the happening of rock-burst and different theories of grading and prediction it in different sub engineering. This article focuses on research of prediction of rock-burst happened in Kuocangshan extreme long-tunnel engineering, comparison of tunnel carving details in the performing stage and prevention measures. As a result, the article discussed the application of prediction of rock-burst in Kuocangshan tunnel engineering, discovered the original tectonic stress field and characters of rocks in the tunnel and fractal intensity and basic distribution rules of Kuocangshan tunnel,and mentioned engineering measures in prevention of rock-burst.Besides, it is by using FLac finite difference mothed that simulate and analyse variation of stresses on the base of geological conditions and physical mechanics functional data in the area of this engineering. And the influence of tunnel depth and angle of the main stress and the axial of tunnel is considered and analysed.Then rock-bust prediction to tunnel through stress crition method.By the comparion between prevention rock-bust and practical rock-bust,the result discloses the application of theoretic model and finite element model and the accuracy and reasonableness of tectonic stress field analysis. On the base of above performance, rock-burst prediction and efficient prevention measures that can bring out highly value in application of tunnel project have been used in the construction of Kuocangshan tunnel.