Research Of Open TBM Construction Geology Risk Assessment And Control

TBM tunnel construction is widely used because of its advantages of safety,efficiency and environmental protection.However,TBM still poses great risks in terms of construction safety and speed in complex geological environments.Therefore,this thesis focuses on the risk assessment and control method of TBM construction geological hazard,and applies it to verify in actual engineering,The main research contents obtained are as follows:(1)Through the statistical analysis of TBM construction at home and abroad,the geological disasters related to fault fracture zone,water-rich zone and rock-burst risk zone are the most frequent disasters in TBM construction,accounting for 36.4%,32.7%and 12.7%.Combined with the specific analysis of the project,it is found that with the increase of the scale of the three adverse geological disasters,the impact on personnel,equipment and construction will gradually expand,and eventually it can even be extended to casualties,equipment damage and long-term equipment shutdown.Based on system safety science,the above three adverse geological risk factors are analyzed from four aspects: staff factors,mechanical equipment factors,environmental geological factors and management factors,and the fishbone diagrams of the three adverse geological risk factors are given respectively.(2)Aiming at the lack of unified and effective risk grading of TBM construction geological disaster risk,an LS-BP risk grading analysis method that takes into account the advantages of risk matrix method and BP neural network method is proposed,which realizes TBM Risk classification of construction geological hazards.On this basis,the risk grading acceptance criteria and construction risk grading control process are proposed,and targeted risk control schemes for different risk levels are proposed.Based on the above research,an intelligent assessment system was designed and developed by MATLAB to realize the intelligent assessment and control decisionmaking of TBM geological risk disasters.(3)The results of this research are applied to the EH project,and the intelligent evaluation system is used to assess the risk of the application cases: the risk level of the fault fracture zone encountered by KS160+046 is level III.The risk level of the waterrich zone of KS179+987 is level IV.The risk level of the rock burst risk zone of KS230+998 is level III.The risk level and risk control scheme given by the intelligent evaluation system have been effectively verified in actual engineering.The TBM construction geological risk identification method proposed in this thesis is reliable and practical,which provides technical guarantee for the safe and efficient TBM excavation.