| 摘要 |
PURPOSE:To perform excavation work without curing period for upper timbering works by a method in which formworks for lower concrete timbering works are hung down from the upper concrete timbering work already constructed, the lower timbering works are constructed, and excavation beneath the lower timbering works is made. CONSTITUTION:A body wall 13 for a vertical pit and a shaft is forwardly constructed of a continuous underground wall, etc., and timbering works 14 and 15 for concrete sheathing are constructed along the inside of the body wall 13. The ground 18 in the wall 13 is then excavated from beneath the timbering work 15 to beneath the timbering work 16. A steel material 1 is hung down through the hole of a sleeve tube 11 buried in the timbering works 14 and 15 and hooked on the upside of the timbering work 14. A hanger 3, a bottom formwork 7, a side formwork 8, and an auxiliary formwork 12 are hung down from the lower end of the hanging steel 1, reinforcing bars are set in the formworks, and concrete is placed to construct a timbering work 16. Immediately after the construction of the timbering work, the subordinary excavation can be performed. |
