| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an underground structure with a groundwater conduction function which is capable of presenting effectively both a rock mass collapse prevention function and a water conduction function without eccentricity and, when the water conduction function is deteriorated by clogging, to recover the deteriorated water conduction function. <P>SOLUTION: An underground structure 8 comprises a plurality of lines of doughnut-shaped bag body rings 10, 10, ... which are provided around the underground structure 8 and are expanded by being filled internally with back-filling materials to be brought into contact with both an outer surface 9 of the underground structure and an excavation surface (g) of a rock mass confronted with the outer surface, and water-permeable back-filling material rings 7, 7, ... which are provided in a space S formed from at least one set of neighboring doughnut-shaped bag body rings, the outer surface of the underground structure and the excavation surface. Further, holes for cleaning are provided. <P>COPYRIGHT: (C)2013,JPO&INPIT |
