A Study On The Prediction And Prevention Of Rockburst In The Traffic Tunnel Of Jinping Ⅱ Hydropower Station

Tunnel engineering and underground engineering will be highly developed in the 21th century. Some tunnels will be designed and constructed in deep strata , in high field stress or under the sea, these provide one big vast space for tunnel construction geology calamity, particularly for the rock burst. Whether the success of the prediction and prevention about rockburst or not will affect the schedule of construction, in addition to the success or failure of the engineering. Now the study about prediction and prevention of rockburst is still not systemic, so with the development of engineering construction, these problems are more necessary and more important than before.This paper studies the traffic tunnel in Jinping II hydroelectric station, Reference to the former achievement, using system analysis which includes laboratory test , surveys and study at the engineering area, quantitative analysis and qualitative analysis. Several methods have been used for the prediction and prevention of rock burst, by way of a large number of analog computations, some feasible , factual or convenient measures have been put forward,, There are some primary study achievements as follows:(1) For the first time AHP—FUZZY is used to predict rockburst, which includes three basic factors, such as rock property, field stress condition as well as rock structure condition, and there are 8 concert sub-factors in 3 basic factors. The influence intensity (weight) of various sub-factors is confirmed by Singly Sequencing of hierarchy and whole Sequencing of hierarchy, finally the intensity grade of rock burst will be predicted. The AHP—FUZZY integrated method of rock burst is a method of the most total, the most systemic and the most integrated, for it includes 8 influence factors.(2) In the computer assistant decision—making system, whether the rock burst will occur or not will be judged firstly, then the result of the rock burst will be predictedo At last, the total flow chart and the flow chart of each sub-system are given too.(3) In the prediction of rock burst by stress intensity ratio, not only the maximal tangential stress valve of each typical section can be gained by finite element analysis, but also the exact solution of semicircle—straightwall section can be acquired by using FU BIAN HAN SHU, which provide exact parameter for the prediction of rock burst.(4) In the nonlinear integrated prediction of rock burst, the same result can be gained by using Bake — Propagation Artificial Neural Networks in traffic tunnel of Jinping II hydroelectric station.(5) with regard to the influence of rock burst from different section shape, the following conclusions can be gained by analog computation analysis after different sections have been excavated,, Firstly, The section of curve shape is better than the straight line shape; The section which has no small corner is better than the section which has small corners, for the concentration of stress is smaller in the section of curve shape. Meanwhile, In the prevention of rockburst, from theory of elasticity the shape of XIE DONG in...