Failure modes of the steel lining of underground reservoirs for compressed air energy storage (CAES)
Compressed air energy storage (CAES) in caverns, shafts or tunnels makes use of the high resistance of the surrounding rock mass to the gas pressure. A lined rock cavern (LRC) is the most attractive concept. The gas pressure is borne by the rock, while the tightness of the system is guaranteed by a composite lining consisting of an inner thin steel shell and an outer reinforced concrete shell. We investigate the following failure modes of the steel shell: tensile failure at the maximum operating air pressure, buckling at the minimum operating air pressure and fatigue during cyclic loading. Rock-lining interaction is analysed assuming the rock as a no-tension material obeying the Mohr-Coulomb failure criterion. The computational results show that in tunnels and shafts of 4 m diameter, safety against fatigue or buckling limits the operational air pressures to a maximum of 10 MPa, if the rock is softer than 5 GPa. The results also illustrate some limitations of the widely used constitutive models, which may be very important for studying the rock-lining interaction during cyclical loading. Compressed air energy storage (CAES), tunnel, shaft, lining, feasibility.