VERTICAL SHAFT DIAMETER WIDENING METHOD AND DIAMETER WIDENING USED THEREFOR

摘要

PURPOSE: To make it possible to easily widen diameter in a free position after the excavation of a vertical shaft. ;CONSTITUTION: In the ground 40 around a vertical shaft 36 into which segments 31 are constructed, the ground 40 around the vertical shaft 36 corresponding to a diameter widening starting position to start construction of a required diameter winding vertical shaft 37 is improved. A starting base 35 capable of installing a diameter widening device 1 by which the improved ground can be excavated in the shape of a circle is formed to install the diameter widening device 1 in a state excavating vertically downward. The ground corresponding to a diameter widening vertical shaft is excavated vertically downward and, at the same time, the segments 31 in the vertical shaft are removed. Lining of the excavated ground is constructed with diameter widening segments 32 to construct the diameter widening vertical shaft.;COPYRIGHT: (C)1993,JPO&Japio