| 摘要 |
The specification discloses apparatus and a process in which the stack of concrete or hard rubber spacer rings used in raising manholes is eliminated. It is replaced with a sleeve which is taller than the required distance between the top of the manhole and the level at which the casting and manhole cover are to be finally located, but which is sufficiently flexible in a vertical direction that when a casting is located in the top of the sleeve, the sleeve compresses downwardly. The height of the casting is fixed by a casting support resting on the pavement base coat or other base surface to which the final pavement will be applied around the casting. The sleeve is sufficiently stiff in a lateral direction that it does not collapse inwardly when backfill is packed in and around the exterior of the sleeve. The casting support is removed and the final layer of pavement is applied over the base surface.
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