Abstract: This paper focuses on the way to get the value of rock resistant coefficient in high-speed railway tunnel. It runs the radial hydraulic pillow testing to measure the radial deformation during various pressures on Shanghai-Kunming high-speed railway tunnel. Based on field test data and combining different constitutive models, five theoretical calculation models for tunnel rock resistant coefficients are established. They are ideal elastic-plastic model, burst fissure elastic-plastic model, plastic softening rock model, Lade-Duncan criterion model and unified strength theory model respectively. Twenty tunnels are classified and the corresponding theoretical values of surrounding rock resistance coefficients are calculated respectively using the proposed models. To compensate the limitation of field test number, the numerical simulation of the research tunnel is carried out. Then the theoretical calculation values, field test values, numerical simulation values and standard values of rock resistant coefficients are compared and synthesized at different buried depths, rock grades and geological conditions. The recommended values of rock resistant coefficient of large section high-speed railway tunnel are proposed. The recommended value breaks through the limit of rock resistant coefficient standard values in ordinary high-speed railway tunnel based on elastic model. Also the recommended value can provide the theoretical basis for optimizing the design of the tunnel structure and making full use of the bearing capacity of the surrounding rock.

Key words: high-speed railway tunnel, rock resistant coefficient, radial hydraulic pillow testing, theoretical calculation model, numerical simulation