CONSTRUCTION METHOD FOR LARGE-SCALE CAVE STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a construction method for a large-scale cave structure capable of effectively preventing the rupture of natural ground even though there is a defective baserock area such as a shuttered zone at the outer periphery of the excavation position of the cave portion and also capable of avoiding an enlargement of timbering. ;SOLUTION: A large-scale cave structure is built by excavating a cave portion 10. The cave portion 10 comprises a cave ceiling portion 10a and a cave side wall portion 10b. Before the excavation of the cave portion 10, the excavation of advanced work gallery 12 is carried out. The advanced work gallery 12 is built near the proposed site for constructing the largescale cave structure and is provided on an almost central axis of the cave ceiling portion 10a. From the inside of the work gallery 12, a baserock timbering work 14 extending radially toward a proposed excavation land of the cave ceiling portion 10a is embedded and installed. The upper end side of each baserock timbering work 14 is fixed to the inside of the work gallery 12. When the baserock timbering work 14 is embedded and installed, the weight of baserock at the upper side of the cave ceiling portion 10a to be excavated is actually suspended and supported by the baserock timbering work 14. Thereafter, the cave portion 10 is excavated.;COPYRIGHT: (C)1999,JPO