| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotary tubular foundation having ground subsidence preventing function, which can exhibit resistance to twisting force and subsidence force of tubular foundation at the time of burying a foundation for a single pole by rotation, moderate stress concentration in the vicinity of a rib plate apex part of a bracket, prevent fatigue crack by welding, and adjust the bolt position of the bracket in conformation to the size of pole diameter. SOLUTION: The tubular foundation 1 to be buried by rotation includes a tip blade 2 provided at the tip thereof. The tip blade includes a spiral plate 3 obtained by forming a sheet member into a substantially one-turn spiral shape, a part of the spiral plate being partially protruded from the tip of the tubular foundation 1, and the other part being fixed in contact with the inner circumference of the tubular foundation. The start end 4a and terminal end 4b of the spiral plate 3 are connected by a plate part piece 6 fixed to the outside of the spiral plate. In addition to an excavating blade 8 formed by extending the plate part piece, one or more excavating blades are fixed to the outer circumference of the spiral plate, and the entire outer diameter of these excavating blades is equal to the tube diameter of the tubular foundation. COPYRIGHT: (C)2008,JPO&INPIT
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