Geotechnical safety program for underground storage caverns in salt

Considering the large volume and different types of material stored in salt caverns, it is important to ensure that the salt cavern be designed, constructed and operated safely. Since salt caverns are constructed in a geological formation, the structural safety problem of a salt cavern is essentially a geotechnical problem. In this paper, we describe the application of the Geotechnical Safety Program (GSP) to a gas storage cavern in salt, focusing on the first two components - performance criteria and design assessment. To develop the performance criteria, we considered performance aspects in different categories. For each performance aspect, we developed the performance criteria by determining the consequences of failure, selecting a tolerable level of risk, establishing criteria of performance, and ensuring that the criteria meet appropriate legal requirements and accepted standards of practice. The design assessment was conducted by checking the design conditions, identifying the critical mechanisms of performance, identifying typical and critical sections, reviewing the field and laboratory data, identifying major uncertainties and critical aspects of performance, and recommending actions to improve safety. Based on the design assessment, we identified several performance aspects which do not meet the performance criteria and recommended changes and/or measures so that the performance criteria can be met.