The harmful matter which remains behind in method of enclosing the harmful matter and

摘要

PROBLEM TO BE SOLVED: To provide a safe and easy method for trapping harmful substances remaining in the ground. SOLUTION: While avoiding contact with a harmful substance, boring is carried out downward to at least a position C where the boring ends mutually intersect from positions A, B sandwiching the harmful substance Z at a gap from both sides of the harmful substance Z and such a boring work is carried out at prescribed gaps and a grout material is jetted between neighboring drilled holes 1 to form a continuous wall 5 to trap the harmful substance Z.