| 摘要 |
The present invention relates to a Top-down method for constructing an underground structure using a steel pipe, capable of improving performance of a structure and usability for a space by forming a CFT pillar with excellent structural performance using the steel pipe and enabling the CFT pillar to be rigid-connected to a girder. The Top-down method for the constructing the underground structure using the steel pipe includes: (a) a step of boring a boring hole at a position where the pillar is installed and inserting and fixing the steel pipe into the boring hole; (b) a step of forming the CFT pillar by placing infilled concrete into the steel pipe and embedding the lower end of an anchor bolt in the infilled concrete in order for the anchor bolt to protrude from the upper end of the CFT pillar; (c) a step of bonding a steel frame beam for constructing the bottom on a first floor, onto the CFT pillar by using the anchor bolt; (d) a step of arranging a slab reinforcing bar for constructing the bottom in a first floor, arranging a vertical reinforcing bar and a stirrup around the CFT pillar, and arranging the vertical reinforcing bar and the stirrup on the upper part at a fixed height from the lower surface of the steel frame beam; and (e) a step of placing the concrete in order for the slab reinforcing bar, the vertical reinforcing bar, and the stirrup to be embedded, wherein the end of the vertical reinforcing bar protrudes to the outside of the concrete. |
