Large Deformation Control Technology of Tunnel Based on Energy-Absorbing Damping Layer
摘要
The excavation of tunnel in soft and broken surrounding rock often leads to large deformation of tunnel. The design and construction of large deformation tunnel support is the focus of long-term concern in the field of tunnel engineering. In this study, polyurethane energy-absorbing damping layers with different densities were prepared and tested indoors. It was found that it has large deformation, high ductility, good energy-absorbing characteristics, excellent cushioning characteristics, low strength and low elastic modulus. It has the potential to be applied to the buffer yielding support of large deformation tunnels. In order to evaluate the performance of polyurethane energy-absorbing damping layer, the finite element analysis of the application of polyurethane energy-absorbing damping layer with different thickness and density in large deformation tunnel is carried out. Compared with rigid support, polyurethane energy-absorbing damping layer can transfer the plastic deformation of lining structure to itself, which can effectively alleviate the stress state of secondary lining structure. Based on the numerical simulation test results, the polyurethane energy-absorbing damping layer with a thickness of 20 cm and a density of 100 kg/m3 was applied to the large deformation tunnel project, and the large deformation of the tunnel was effectively controlled.