Abstract: As porous medium, concretes of the shaft lining of coal mine are affected by underground water seepage flow. The three-parameter strength criterion and elastic-plastic theory are used to obtain the stress distribution of shaft lining in the elastic zone and plastic zone, and the analytical expression between the groundwater pressure P₀ on shaft lining and the plastic zone radius r_p. The results show that the ultimate bearing capacity of the shaft lining is the largest when seepage flow is not considered, and the hoop stress σ_θ of the shaft lining is about 2.7 times of the uniaxial compressive strength of concrete cubes. However, when seepage flow is considered, the ultimate hydraulic pressure that the shaft lining can bear gradually decreases with the increases of porosity β, and when β equals 0.2, the hoop stress of the shaft lining is about 2.4 times of the uniaxial compressive strength of concrete cubes. Therefore, seepage flow has significant influence on the stress distribution of the shaft lining. Moreover, with the increase of hydraulic pressure, the radial stress σ_r and the hoop stress σ_θ of concrete in the elastic zone gradually increase, however, when the hydraulic pressure reaches or exceeds the limit pressure(corresponding to the plastic radius), the radial stress σ_r and the hoop stress σ_θ in this position remains unchanged. The results provide theoretical reference for the structure design of shaft lining.

Key words: shaft lining of coal mine, three-parameter strength criterion, elastic-plastic theory, fluid-solid coupling mechanism, groundwater seepage flow