Tunnel Construction Ahead Geological Forecasting Method Research In Karst Area

Based on vast literatures and extensive practices, rely on Yanmenguan highway tunnel in Shanxi province, Shimen mountain and Jiaojin mountain city tunnel in Dalian, Wangjialing, railway tunnel in Yiwan line survey data, Taihang mountain railway tunnel in Shitai line, reference and analysis Shimenao highway tunnel in Jingzhu line, Yuanliang mountain tunnel in Chonghuai line, Wulong mountain tunnel in Yuhuai line and so on types data of tunnel construction ahead geological forecasting method research in karst area, by local experimentation, theory analysis, numerical simulation and parameters test at laboratory, this thesis deeply researched tunnel ahead geological forecasting different methods in karst area base on rock dissolve cause of formation and classify laws. It have applied to practice engineering to obtain a series of avail research fruit on theory and practice.Firstly, by researching the characteristic and cause of formation and classify law of rock dissolve in karst area, summarized and concluded disaster types and stream water quantity standard for roadway and railway tunnel, by numerical simulation to research the effect of tunnel construction face around size and position of rock dissolve distributing at filling water or no. and explain structure face growth and spacial position of rock dissolve determine possibility and size of rock dissolve gushing. Its result put forward research content, task and target of tunnel ahead geological forecasting in karst area.Secondly, Summarizing and analysis the characteristic and localization of every method of tunnel construction ahead geological forecasting in karst area to make out single parameter single-array, single parameter multi-array, muti-parameter muti-array and synthesis parameter method four types disaster geological forecasting pattern. Its discusses tunnel geological forecasting method development trend.Thirdly, by researching tunnel ahead geological forecasting optimize method to make out synthesis parameter method forecasting theory, base on effect of SEM(seismic and electric method) to obtain the conclusion that parameter of "velocity and resistivity" is the best optimize synthesis parameter in existence condition. It puts forward result of general suitable rule to karst area is "synthesis parameter, length and short distant combining, outside and inside hole consider, long time tail after and geological disaster counterplan".Fourthly, base on advancing forecasting reliability, precision and explain ability it researches three critical technology to ensure tunnel construction safety from method of tunnel geological information number identify technology to research long time tail and from TEMT(tunnel electricity and magnetic method) to research the new forecasting method and from three dimensions number data graph and image process technology to advance forecasting explain precision.Finally, How to effectively translate and combine geological forecasting data to tunnel excavating and combine with other data example for tunnel distortion and quality measuring and surround rock classify and so on to estimate excavating face surround rock stabilization. Put forward surround rock classify way for tunnel ahead excavating face by synthesis parameter of wave velocity combining resistivity. Put forward the tunnel construction geological disaster counterplan system, It may effectively prevent geological disaster to happen in tunnel and ensure tunnel construction safety.Above established tunnel ahead geological forecasting method system in karst area.