| 摘要 |
Method and apparatus for forming inverts in a manhole base using a double pour technique. In the two pour technique, the manhole base is initially formed. Thereafter, channel invert forms are precisely aligned with the sidewall openings by circular shaped alignment members arranged within the manhole openings to assure precise alignment therebetween, whereby the invert formed within the interior of the manhole base by pouring the casting material into the interior of the base member assures the formation of an invert which is in precise alignment with associated openings in said sidewall. The apparatus utilized for the double pour technique incorporates at least one adjustably positionable channel-forming assembly for forming an invert for communicating between associated sidewall openings each having a central axis whose intersecting central axes define an angle different from 180.degree.. The invert form is substantially completely flexible. Alignment members on the invert form and a flexible internal member, either alone, or in cooperation with a joining bar, assure precise horizontal alignment between the channel-shaped projections utilized to form the invert and also prevent flotation of the invert form during formation of the invert. A method and apparatus is disclosed for producing a resilient, flexible invert. |
