The Geological Radar Inspection And Numerical Simulation Analysis Of Tunnel Lining Quality

Due to the concealment of the tunnel construction and the complexity of the construction process, some quality problems of tunnel lining is coming in different degree, which inevitably affecting the stress and deformation of surrounding rock, and even having great influence on safety of normal running of the tunnel. So in order to ensure the safety of the tunnel, comprehensive test about the quality of the lining should be taken, and analyzes the possible impact of lining defects.Firstly, testing and detection image of shangguan tunnel lining quality by combining the principle of Geological Radar nondestructive is evaluated in this thesis, which indicates that there are no quality defects in tunnel lining.And then numerical calculation model of Shangguan tunnel is established based on Distinct Element Method. The major defect of general highway tunnel lining after construction is simulated calculation to analysis the stress and deformation of surrounding rock, which is compared with the stress and deformation of surrounding rock under the design cases. Analysis shows that, firstly, the influence of secondary lining on the stress and deformation of surrounding rock is small when the concrete thickness of secondary lining is 5 centimeters smaller than the design concrete thickness or the maximum of anchor the longitudinal spacing is 13 meters. Secondly, although the maximal displacement of surrounding rock is still less than the displacement convergence alert values, the concrete thickness of preliminary bracing being 5 centimeters smaller than the design concrete thickness or the preliminary bracing of upstairs section having 5 centimeters local cavity with surrounding rock has a great influence on surrounding rock stress, construction treatment is needed in time. Thirdly, the influence of preliminary bracing's defect is bigger than the defect of secondary lining concrete thickness when the concrete thickness is 5 centimeters smaller than the design thickness. Fourth, the influence of the 5 centimeters thickness of the hollow between the preliminary bracing of upstairs section and the surrounding rock is bigger than the influence of preliminary bracing concrete thickness defect.