Field evaluation of permeability of concrete linings and rock masses around underground lined rock caverns by a novel in-situ measurement system

In this paper, we introduce a novel in-situ permeability measurement system and present the results of field permeability testing using the developed system. Using a modular structural design and wide measurement range from low to high permeability, the developed system was capable of measuring in-situ scale permeabilities of concrete linings, construction joints and rock mass around excavated rock caverns. Such measurements have been extremely limited so far but are essentially required in estimating the sealing performance of underground storage caverns. The experimental results of a concrete block model test as well as field permeability measurements of concrete linings and the excavation damaged zone (EDZ) around a lined rock cavern (LRC) in a pilot plant for underground compressed air energy storage (CAES) were presented. From these experimental measurements, we could verify the effective applicability of the developed system to a wide range of measurement conditions, from the low permeability concrete lining matrix to the highly permeable construction joints and fractured rock masses around underground rock storage caverns.