抄録
Hydraulic containment type underground LPG storage cavern applies the artificial water curtain system to preserve the LPG by permanent water flow toward storage caverns. Therefore, the storage caverns have received high water pressure during cavern excavation and influenced on the rock stability. In this paper, the authors have concerned the development of excavation disturbed zone (EDZ) under high water pressure and applied the FEM rock mechanical analysis to predict the deformation by high water pressure. Based on the analytical results, we designed a 10m grouting zone to cover the EDZ for rock permeability reduction. For the special geology structure (e.g. fault and fractured zone), we designed high strength rock bolt and applied fiber reinforced shotcrete based on the observational construction method. After cavern excavation was completed, we have submerged the water curtain tunnel and compressed the water curtain system to examine the rock mechanical stability of storage cavern. As the results, there was no deformation observed while water curtain pressure reached to 1.2MPa. Consequently, the water curtain compression test has achieved to validate the rock mechanical stability of the underground LPG storage cavern.
