Stability analysis of surrounding rock of multi-cavern for compressed air energy storage

Compressed air energy storage in artificial caverns can mitigate the dependence on salt cavern and waste mines, as well as realize the rapid consumption of new energy and the "peak-cutting and valley-filling" of the power grid. At the same time, the safety and stability of the surrounding rock of gas storage has attracted extensive attention. Based on finite element simulation, a numerical model of shallow-buried double-chamber for compressed air energy storage is established, and the influence of working pressure, cavern type, pillar space, and cavern diameter on the mechanical behavior of surrounding rock is analyzed. It is discovered that the cavern type significantly affects the response of the surrounding rock, whose deformation and plastic strain in the horseshoe-shaped cavern is significantly larger than that in the circular cavern. For circular caverns, the pillar space of 2 similar to 3 times the cavern diameter is only suitable for low working pressure, and the plastic strain and deformation of surrounding rock increases sharply with the increase of working pressure. It is more appropriate to select the pillar space that is 4 times the cavern diameter when the working pressure is greater than 16 MPa. With the increase in the cavern diameter, the maximum deformation of the surrounding rock accelerates rapidly.