| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceiling base structure in which square cylindrical ceiling joists (namely, square cylindrical members) can be easily and firmly mounted together in the ceiling base structure of a gridiron structure, and also quake resistance is greatly improved with a wide area.SOLUTION: A ceiling base structure comprises a large number of hollow first metallic square tubes 1 arranged in parallel at predetermined intervals, and a large number of second metallic square tubes 2 perpendicular to the metallic square tubes 1 and arranged in parallel at predetermined intervals. End parts selected from among the first metallic square tubes 1 or the second metallic square tubes 2 are connected together by a pair of connection metal fittings 13a, b of a cross section channel-shape and bolts 10, the bolts that are used for vertically connecting the connection metal fittings 13a, b with the end parts selected from among the first metallic square tubes 1 or the second metallic square tubes 2. Accordingly, the ceiling base structure with a wide area is provided which can endure a vertical load and also tensile force/compressive force due to strong swinging in the up-and-down direction and in the horizontal direction in an earthquake. |
