To prevent a manhole from floating up in the case of application of a fluidizing process, by projecting anchor attaching bracket from the outer periphery of a resin manhole, and by driving anchors into the peripheral wall of an excavated pit.
A sand base 2 is formed in the bottom part of an excavated groove 1, and a manhole 11 is set thereon. Anchors 18 are driven into the side peripheral wall 1A or bottom peripheral wall 1b of an excavated pit 1 through anchor brackets 7 of the manhole 1 so as to incorporate a float-up preventing means to the resin manhole 11. Further, slurry in which cement or sediment is dispersed is cast into the pit so as to carry out a fluidizing process. Excavated earth obtained when the excavated pit 1 being formed can be used as the sediment. Accordingly, it is possible to simply provide a means for preventing a resin manhole from floating up.
SUZUKI TADANOBU
HASEGAWA TADASHI
