To maintain the waterproofness of a waterproof sheet, and easily attaching a support rib by providing internal screws at upper and lower parts of a long nut, by screwing an anchor bolt to the support rib, and by bonding a collar to the waterproof sheet by an adhesive layer.

In a connection tool 1, internal screw parts 2a and 2b are mutually watertightly formed at the upper and lower parts of a long nut 2, a synthetic resin layer 3b is made to cover a collar body 3a integrated with the long nut 2 as a collar 3, and an adhesive layer 4 and releasing paper 5 are provided onto the surface. In the construction of a tunnel or the like, a concrete anchor 6 is placed onto a sprayed concrete surface 10 that is formed on the natural ground, the internal screw part 2a of the connection tool 1 is screwed into a connection bolt 7 exposed from a hole by expanding a waterproof sheet, and the releasing paper 5 is removed for bonding the collar 3 to the waterproof sheet 11. Then, the internal screw part 2b is screwed to a support rib for supporting a support, and covering concrete is placed, thus maintaining the waterproofness of the waterproof sheet 11, and easily attaching the support.