| 摘要 |
<p>The method forms a concrete well, inspection shaft etc. with a vertical annular wall, by pouring concrete into shuttering. This forms a flat annular top surface, and also a lateral connecting opening below this surface. A connecting face is set back from the outside surface in the opening, being joined to the latter surface via an intermediate one. This intermediate surface (11) is arched, so as to form a stronger support for the overhanging part of the wall above it.</p> |
