As the generation method of the blowhole in blowhole shield tunneling method and in the blowhole where in the foam material the blowhole

摘要

PROBLEM TO BE SOLVED: To perform a foam shield construction method, without using the other additive and an auxiliary construction method, even in the highly water permeable gravel ground.;SOLUTION: One kind selected from CMC, guagum, and an alginic acid or a mixture of these is added to a foaming agent being a main agent as a thickener. A foaming material solution adjusted to viscosity of 300 to 500 mPas, is foamed by prescribed foaming power via a foaming device 18, and an aqueous solution of a metal ion is added to and mixed with foam provided just after foaming.;COPYRIGHT: (C)2005,JPO&NCIPI