Objective In the solution mining process, underground salt caverns often encounter challenges, including eccentricity in cavity dissolution and irregular shapes caused by the presence of insoluble interlayers, which can lead to uncontrollable interlayer collapse under natural conditions. Controlled blasting of the irregular rock mass in bedded salt caverns can improve cavity shape and mitigate potential hazards. This approach effectively enhances both the speed and efficiency of cavity construction.

Methods This paper aims to study the response of insoluble interlayers in bedded salt caverns and the surrounding rock mass to blasting. To this end, a numerical model was constructed using ANSYS/LS-DYNA software, to simulate the blasting of bedded salt caverns containing insoluble interlayers. The subsequent simulations revealed the failure modes of irregular rock mass in solution-mined cavities resulting from a single explosion source, as well as the degree of damage to the surrounding rock under the influence of various explosive equivalents. Through analyzing the correlations between different explosive equivalents and their corresponding blasting effects, a safety evaluation system for salt cavern gas storage was established. This system includes the following indices: horizontal displacement of the surrounding rock, vertical stress, effective plastic strain, roof settlement, and shear stress distribution.

Results The horizontal displacement of the surrounding rock serves as an effective index for characterizing the deformation state of the lateral surrounding rock in solution-mined cavities. Additionally, the effective plastic strain and shear stress distribution can be utilized to accurately represent the damage state of the surrounding rock, enabling predictions regarding the failure conditions of solution-mined cavities. Meanwhile, the vertical stress and roof settlement index is particularly sensitive in predicting the collapse of cavity roofs.

Conclusion Numerical simulations were conducted to replicate blasting in irregular cavities of bedded salt caverns, utilizing the Riedel Hiermaier Thoma (RHT) constitutive model for salt rock. Five indices were specifically analyzed to investigate damage at various positions within the salt caverns subjected to different blasting conditions. Based on the existing salt cavern stability evaluation model, the proposed stability evaluation indices are demonstrated suitable for solution-mined cavities under dynamic loading, thereby enhancing the safety evaluation system for salt caverns. The findings of this study provide a reference for evaluating the stability of salt cavern gas storage.