Tunnel Dynamic Monitoring And Inversion Analysis In Process Of Construction

With the development of society, demands for communication and underground space are much more than ever. Tunnel engineering will develop promptly in 21st Century. To guarantee safety working and fair excavation method, as one necessary process, monitoring must make sure coordinating with other steps and continuously collecting data. So monitoring is a dynamic working and an eternal and always new subject. Inversion analysis bases on surrounding rock's displacement for material mechanic parameters and original ground stress, which attracts more attention in field of engineering since prompted in 70s,20th Century. This paper takes four highway tunnels, which is on the YinWu Line, of the terrene of GuYuan, NingXia municipality, as engineering background. Use many field measuring tools and methods to get data. Use some no-classical math theories such as Grey System, Neural Net and Fuzzy control theory, and finite element numerical simulation to analysis and study coherent subjects.1.New devices and instruments always bring efficiency to tunnel construction, which is no exception of detection work. Firstly it surveys rock displacement measuring and lining stress measuring of normal monitoring methods. Then it does full research on newborn laser cross-section device and ground penetrating radar.2. Rock displacement monitoring is the core of safely working and proper technology of tunnel construction. Forecasting in precise is the key to making right decision. Grey system and neural network are two atypical math methods, which are used to forecast surrounding rock's convergence. After comparison, the three forecasting methods, unequal time interval GM(1,1)model, BP neural network model, and normal math model, show their special features and applicability.3.Safety is NO.1 position in construction. Where there occurs rock abnormal distortion, any forecasting method maybe lead to big errors. Rock displacement control is a new conception, coupled with setting up proper displacement warning limit for local tunnel construction. Fuzzy control theory is used to build up tunnel stability monitoring and control math model, which supports rock displacement self-monitoring system new way.4. Field measuring is the only way to get lining structure stress. Nowadays theory mechanical calculation has much deviation from real lining structure stress, so such calculation result can't be used in tunnel design. Tunnel lining structure stress has much questions to answer, field measuring can solve this problem. For terrene reason, this paper mainly study in Shallow-buried loess area. Set up FEM to study effects of various excavation types and spatial excavation to surrounding rock's contact stress.5. Inversion analysis is using surrounding rock's displacement to obtain rock mechanical parameters and original ground stress. This research attracts more attention in field of engineering since prompted in 70s. This paper aims at popularization, which means through simple calculation model to solve practical engineering problem. Firstly set up finite element model(FEM) to study effects of buried depth, rock mechanical parameters, lining thickness, excavation types, and spatial excavation. Secondly introduce BP neural network to fitting nonlinear relationship between rock mechanical parameters and key points' displacements. Finally set up tunnel inversion analysis flow sheet, input field measuring data and get rock mechanical parameters.