| abstract |
(57) [Summary] [Problem] A composition for an injection material to be used has no problem of fire or skin irritation, has excellent permeability to ground, etc., has a high curing speed, and has a water stopping property and strength of the cured product. Providing an excellent construction method for the mountain tunnel construction method. In an auxiliary construction method of a mountain tunnel construction method, as a composition for an injection material, a monovalent or divalent metal salt of (meth) acrylic acid, an oxyalkylene group such as polyethylene glycol di (meth) acrylate, and two or more oxyalkylene groups. (Meta) A water-soluble compound having an acryloyl group and a composition comprising water are used. |