EXCAVATING CASING, SQUARE HOLE EXCAVATING METHOD, DECONTAMINATED WALL CONSTRUCTING METHOD IN CONTAMINATED GROUND, AND CONTAMINATED GROUND DECONTAMINATING/REPLACING METHOD

PROBLEM TO BE SOLVED: To efficiently carry out excavation of a square hole without waste, to thereby achieve saving in labor, reduction of construction costs, and shortening of a construction period. SOLUTION: There is provided an excavating casing 1 which is formed of a square steel pipe 3 or by combining the square steel pipe 3 with a U-shaped steel member 16. A square hole excavating method is carried out by using the excavating casing 1, and removing the ground G in the excavating casing 1 by means of an auger screw 4, a clamshell bucket 7, etc. Further by driving the excavating casings 1 connected to each other or overlapping each other to some extent, into the ground, a groove-like square hole 2 or a planar square hole 2 can be excavated, and the square hole excavating method is applied to a decontaminated wall constructing method in contaminated ground or a contaminated ground decontaminating/replacing method. COPYRIGHT: (C)2007,JPO&INPIT