| 摘要 |
PROBLEM TO BE SOLVED: To solve such problems that in protection against underground installed articles by using conventional high strength alloys or a ceramic protection plate, the cutting speed against a diamond-caulked pavement cutting cutter blade is reduced but the underground installed articles cannot be completely protected because they are cut by the pavement cutting cutter, ceramic is expensive and economically inferior when a protection area is wide, and moreover, steel plates need be separately used for a shallowly buried pipe line or the like as a countermeasure against a shock from an excavating machine or the like.SOLUTION: In a hollow flat plate-like box body 1 of which the outer sheath is made of a rigid body, high-strength fiber sheet 2 having a shape spread on the inner bottom surface of this box body 1 is disposed so as to be floated from the bottom surface of the box body 1 by a spacer member 5, and an elastic body 7 placed on the high-strength fiber sheet 2 is stored so that a member housed in the body box 1 is temporarily pressed and held between a ceiling of the box body 1 the elastic body itself. Moreover, the steel sheet 9 is interposed between the spacer member 5 and the high-strength fiber sheet 2. |
