CUT-OFF METHOD OF DEEP WELL IN BUILDING WORK

摘要

PURPOSE: To seal a well pipe by fixing a cut-off pipe with the upper part of the well pipe while pumping up underground water in a deep well and casting concrete on both sides of the cut-off pipe and further placing concrete into a box loaded on the concrete. ;CONSTITUTION: After the deep well is excavated and the well pipe 11 is buried, underground water is pumped up with a pump 21 charged into the well pipe 11. Then, ground concrete 31 is cast on the ground surface around the well pipe 11. While underground water is being pumped up, a cut-off pipe 41 is welded with the upper part of the well pipe 11 and sealed and then the upper part of the cut-off pipe 41 is left and pressure resisting concrete 51 is cast around the pipe. After a box 61, whose top is open, is loaded on the top of the pressure resisting concrete 51 in such a fashion that it may envelop the cut-off pipe 41, pressure resisting concrete 52 is further cast around the box 61 while the underground water is being pumped up. Furthermore, the pump 21 is pulled up into the box 61 and the top of the cut-off pipe 41 is sealed with a cover 71 while pumping up the underground water.;COPYRIGHT: (C)1996,JPO