The large section excavation construction method null by the pipe

摘要

PROBLEM TO BE SOLVED: To ensure safety and reduce the construction cost by arranging long face bolts taking fiber reinforced plastic cable bolt as a core material at suitable intervals in the working face in the interior surrounded with a pipe loop constructed extending over the total length of a start vertical shaft and an arrival shaft, and digging while breaking the bolts. ;SOLUTION: A boring machine 4 is installed on the start vertical shaft 2 side, and a steel pipe 5 is propelled extending the total length from the start vertical shaft 2 to an arrival shaft 3 to construct a pipe roof 6. Subsequently in the interior surrounded with the pipe roof 6, long face bolts 12 having a core material of a fiber reinforced plastic cable bolt having such a length as to extend over the total length of the start vertical shaft 2 and the arrival shaft 3 are arranged at suitable spaces from the working surface parallel to each other. Drilling is started from the start vertical shaft 2, and with the advance of drilling, a timbering is assembled, an intermediate working floor is installed in the middle stage by use of an H-steel and a lining plate, and drilling is performed while the long face bolts 12 are broken by an excavator such as a back hoe or the like on the intermediate working floor.;COPYRIGHT: (C)1999,JPO