Pre-stressed concrete pipe repair procedure consists of winding pre stressing wires round excavated portions in trench and back-filling

摘要

The procedure consists of digging out a trench to expose a length of damaged pipe, making an excavation (8) under a first portion of the pipe centred on a joint (5) between two pipe sections (2, 3, 4), winding, tensioning a sleeved pre-stressing wire round the pipe, and back-filling with earth and compacting before moving on to the next portion. The excavated portions (6, 7) of the pipe have a length equivalent to half a pipe section, and the pre-stressing wires are wound round them from a pipe section joint outwards and spaced at about double the normal spacing before tensioning.