Effects of Hydrostatic Dissolution and Seepage on the Transport and Mechanical Properties of Glauberite

During the development of urban underground space in Chengdu, China, it was found that glauberite rocks in the Guankou formation of the Cretaceous system had extensive dissolution and exerted a serious impact on the safety of the project. At present, research on the transport and mechanical properties of glauberite under hydrostatic conditions in this area is limited. In this paper, the effects of hydrostatic dissolution and seepage on the transport and mechanical properties of glauberite are studied. The results show that the concentration of aqueous solution increases step by step with the increase in the dissolution time of glauberite in still water, indicating that the forward movement of the dissolution front of glauberite rock is not a continuous process and has intermittent characteristics. The dissolution and infiltration of mirabilite seriously deteriorates the physical structure of mirabilite, resulting in a decrease in elastic modulus and an increase in axial deformation, and a decrease in mechanical properties. There are a dissolution layer, dissolution front and undissolved area in the karst infiltration of calcium and mirabilite in the hydrostatic solution, so the mechanism of the calcium and mirabilite karst dissolution process is determined. Because of the dissolution characteristics of mirabilite, underground space development should prevent the uneven settlement of mirabilite, ground collapse, pit and chamber water gushing, corrosive groundwater and other geological problems.