Stability of a lined rock cavern for compressed air energy storage containing a weak interlayer during blasting in the adjacent cavern: model tests and numerical simulation

Abstract To evaluate the stability of a lined rock cavern (LRC) for compressed air energy storage (CAES) containing a weak interlayer during blasting in the adjacent cavern, a newly excavated tunnel-type LRC was taken as the research object. By combining similar model tests and numerical simulation, the dynamic responses and deformation characteristics of the LRC for CAES under joint action of factors including the gas storage pressure, weak interlayer, and blast load were studied. The influences of the thickness, dip angle, and location of the weak interlayer on deformation of the LRC were discussed. The results show that as the gas storage pressure increases, the rate of change in strains in regions of the LRC near the weak interlayer is accelerated, and the gas storage pressure more significantly influences the sealing layer and lining than the surrounding rocks. The presence of the weak interlayer causes stress concentration in the LRC and increases the circumferential strain and residual strain of the LRC. Under the blast load, the right-side wall of the LRC shows the poorest stability, and the presence of the weak interlayer results in the energy loss in the propagation process of stress waves and an increment of peak strain in regions of the LRC around the interlayer. When the weak interlayer is separated from the LRC, as the thickness of the weak interlayer increases, the confinement of surrounding rocks at the interlayer on the LRC reduces and the circumferential strain increases. As the dip angle of the interlayer increases, the peak strain in the right upper side of the LRC grows significantly. As the distance from the weak interlayer to the LRC boundary increases, the circumferential strain in regions of the LRC near the interlayer decreases significantly. If the distance is less than 0.2 r , the increment of the distance significantly affects the peak strain.