Study On Prediction And Forecast Of Geologic Disaster In Highway Tunnel Construction

The trend of modern tunnel is the increase of its length. Fast construction has become the main approach in the field of tunnel construction in this century. Due to the complexity and unpredictability of tunnel construction, under current technical and economic conditions, prediction and treatment of varieties of harmful geological disasters become the major task involved in mountain tunnel construction under complex conditions, especially predictions of varieties of geological disasters draw more and more concerns among the fields of engineering geology and tunnel construction home and abroad and is still not dissolved. It proved that prediction and forecasting during tunnel construction could dramatically decrease the occurrence of such geologic disasters as collapse, water and mud bursting, etc. It could guarantee the construction and decline the cost.Referring to research on the stability and reliabiity of tunnel and underground space structure(50334060), based on the study of three aspects including collapse in hard rock, determination of scale and position of harmful geological body (fault, karst cave, fracture zone) in front of tunnel, rockburst etc.in Fenshui and Bijiashan Tunnel,Tong-Yu Tunnel, this paper drew the following conclusions:(1) During Fenshui and bijiashan tunnel construction, apply software to refer to the unstable block in the hard rock, and achieve the relative position between unstable block and tunnel and safety coefficient of the unstable block, hence predict the collapse caused by the instability of the blocks.(2) Through the detection of geological radar and engineering multi-wave seismograph, it could detect abnormal situations , predict the position, occurrence of the har(?)ful geological body and completeness of the surrounding rock and possibility of water containing in front of the tunnel face, so provide support for the construction units to optimize the construction plan, provide reliable and timely information to avoid possible tunnel accidents, achieving the goal of safe and fast construction.(3) This paper put forward to apply BP neural network to predict tunnel rock burst and developed rock burst prediction system based on Visual C++6.0, chose maximum shearing stress, rock axial compress strength, rock axial pull strength, rock elastic energy index, the ratio between maximum shearing stress and rock axial compress strength, and the ratio between rock axial compress strength and rock axial pull...