To ensure the water cutoff properties of temporary cofferdam works.
The temporary cofferdam works have a plurality of precast panels 20 being parted along the vertical direction and peripheral direction of a pier and having the same constitution. The panels 20 have skin plates 20a, vertical beams, horizontal beams 20c and vertical ribs 20d. The plates 20a are bent arcuately, and formed in a cylindrical shape at the time of connection, and partition the outer circumferential surface of cofferdam works. The horizontal beams 20c are fixed onto end faces in the vertical direction of the plates 20a. The horizontal beams 20c are formed in an annular shape at the time of connection in the peripheral and vertical directions. A mortar layer 24 for cutoff is formed between the underside of the horizontal beam 20c of the precast panel 20 at a first stage placed on a footing 14 and the top face of the footing 14. The mortar layer 24 is fastened on the underside side of the horizontal beam 20c, and formed by filling a skirt section 26 downwards extended along the side face of the footing 14 and the inside of a space partitioned by the top face and side face of the footing 14 with mortar.
TANAKA NORIAKI
MORIYAMA MAKOTO
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