| 摘要 |
PURPOSE:To facilitate a processing work for an underground structure, by a method wherein, before deposited concrete is set, a boundary layer forming liquid is injected into a layer, and an arbitrary boundary layer is formed in the deposited concrete by setting the boundary layer forming liquid. CONSTITUTION:After concrete 2 is placed in an excavated hole 1, an injection pipe 4 is inserted before the concrete is set. A boundary layer forming liquid, for example, plaster, is injected through the injection pipe 4, and a layer 7 of the boundary layer forming liquid is formed through turning of a fan-shaped nozzle 6 mounted in a horizontal direction to the lower end of the injection pipe 4. If the boundary layer forming liquid is set, the concrete 2 is divided into an upper layer 8 and a lower layer 9 with the layer 7 therebetween, the upper layer 8 and the lower layer 9 are brought into a state to be dynamically and chemically separated, and this enables to perform a separate processing thereon. |
