METHOD OF DETECTING DRAIN AND AIR LEAK FROM STORAGE FACILITIES IN BASE ROCK

PROBLEM TO BE SOLVED: To ensure simplification of an execution work process and reliability for a long period. SOLUTION: The storage facilities in a base rock are provided with a pressure proof buffer material 14 set up to an inner surface side of a cavity part 12 formed in a base rock 10 and an air-tight material 16 of metal lining layer or the like of air tightness provided in an inner surface side of this pressure proof buffer material 14. An air leak detection part 18 is arranged in the upward of the pressure proof buffer material 14, a water drain part 20 is provided in the downward. A linear drain material 22 is set up in an external periphery of the pressure proof buffer material 14. The linear drain material 22 is constituted by a fiber having permeability of air and water along a lengthwise axial direction, to be formed with an opening over its total length. The linear drain material 22 has a plurality of turned around annular parts 24 and a plurality of axial direction extended parts 26 crossed so as to be orthogonal to the annular part 24. The drain material 22 is provided with a function of a drain passage and an air leak detecting passage.