STUDY ON THE STABILITY OF COMPRESSED AIR ENERGY STORAGE TUNNELS UNDER DIFFERENT STRESS FIELD CONDITIONS

As a commonly used type of compressed air storage, deep-buried tunnels may face different types of in-situ stress fields. When the tunnel is inflated and pressurized, its stability will be more complicated. We use ABAQUS finite element software to establish three-dimensional models of deep-buried compressed gas energy storage tunnels. By changing the angle between the tunnel axis direction and the maximum horizontal principal stress, the characteristics of displacement, stress and plastic zone are studied and we determine the best axis layout. The results show that under different types of in-situ stress field conditions, the convergent displacement of the tunnel is suppressed after the compressed air energy storage tunnel is inflated and pressurized, the uniformity of the compressive stress of the surrounding rock at each part is improved, and the stability of the tunnel is enhanced; after inflation and pressurization, displacement, stress and plastic zone change to a certain extent with different included angles, and their performance in different stress fields is different; after inflation and pressurization, the plastic zone range of surrounding rock under different stress field conditions is all obviously reduced, only locally distributed at the top of the arch; comprehensive analysis of the changes in the displacement, stress and plastic zone can determine the optimal layout of the axis:in the σ_H and σ_HV type stress field, the angle between the tunnel axis direction and the maximum horizontal principal stress should be less than 45° as much as possible, while in the σ_V type stress field, the angle between the tunnel axis direction and the maximum horizontal principal stress should be slightly greater than 45°. The results have certain reference value for the geological site selection and axis layout of the compressed gas energy storage tunnel.