Numerical study on the damage evolution of UHPC lining in LRC gas storage

Ultra-high performance concrete (UHPC) lined rock caverns (LRC) are regarded as potential underground hydrogen storage facilities in the future. This paper establishes a finite element numerical model of UHPC lined rock caverns to study the damage evolution process of UHPC lining under different influence factors, e.g. rock elastic modulus, lining thickness, and steel plate thickness. Four characteristic internal pressures (P1-P4) are determined based on the damage evolution results. P1: tensile strength is firstly reached on the inner surface of the lining. P2: tensile strength is reached on the total section in the thickness direction of the lining. P3: the maximum plastic tensile strain changes from the inner surface to the outer surface of the lining due to the damage to the surrounding rock. P4: localization of plastic strain through the lining thickness direction, i.e. formation of macro cracks. The increase in lining thickness can significantly delay the damage evolution process of UHPC and increase the maximum gas storage pressure, while the effect of steel plate thickness is negligible under the same increase percentage.