GROUT MATERIAL OF BEDROCK AND GROUTING METHOD

PURPOSE: To improve workability by using a mixed liquid containing cement, water and water swelling fibers, in which absorption, fiber length and a fiber diameter are specified, as a grout material forming an impervious wall by injection into the cracked section of a bedrock. CONSTITUTION: High water-absorbing fibers, in which absorption is decuple or more of their own weight, fiber length is 8-50mm and fiber diameters are 1-50 denier, are used as water swelling fibers. When a first grout material G1 , consisting of a fiber mixed liquid is injected into a foundation rock R, the first grout material G1 , is flowed into opened cracks K. The fluidity of the grout material G1 is increased because fiber surfaces absorb water and have smoothness at that time, and fibers are deposited in the cracks K at low injection pressure and close the cracks K. When a second grout material G2 composed of a cement suspension is infected at pressure higher than the grout material G1 the second grout material G2 is infiltrated and fixed into the cracks K and fine cracks in the peripheries of the cracks K and consolidated. All materials are mixed desirably, and one-stage execution of works is conducted. Accordingly, fluidity can be controlled easily, the dispersion of an injection liquid can be prevented, and strength can be increased.