Creep Properties of Mudstone Interlayer in Bedded Salt Rock Energy Storage Based on Multistage Creep Test: A Case Study of Huai’an Salt Mine, Jiangsu Province

Salt rock is internationally recognized as an excellent medium for energy storage. However, most of the domestic salt mines are lacustrine laminated formations with mudstone interlayers, which have different creep characteristics to pure rocks. Therefore, in this paper, uniaxial compression tests were carried out on a interlayer Huai’an, Jiangsu, China, and multistage mechanical behavior was investigated using acoustic emission (AE) technology. The results show that at low stress levels, axial deformation greater than lateral deformation. As increase level, becomes more significant, corresponding steady-state rates both exhibit nonlinear acceleration loading stress. In initial stage each releases large number AE signals. After stabilization, signals decreased obviously, released last level. Based test data, improved fractional viscoelastic-plastic model fitted it compared Nishihara model. applicability also tested, found be good description after oil erosion. research reflected law certain extent expected serve reference studies long-term stability surrounding bedded