Refurbishment of buried road shafts

摘要

The cement grout (5) is forced at pre-set pressure into the shuttered interval (4) so as also to fill out the cavities (6) formed between road surface (7) and substructure (8) and shaft closure (2,3), preferably using distribution nozzles arranged round the shaft periphery. Grout is pressed in thus outside the shaft and inside between shaft cover and shutting, using an injection pressure of 5-10 bar. The grout is reinforced with glassfibre or plastics fibre. The interval (4) below the shaft frame (3) is first poured with cement grout followed by cement grout pressed in outside the shaft cover. The spray machine used for this comprises water feed and grout and water mixer followed by a distributor complete with branching lines terminating in the spray nozzles.