RENFREW MOTORWAY SEWER

This article is concerned with the design and construction of the Renfrew motorway sewer, which was built to avoid overloading Glasgow's existing sewerage system. Particular reference is made to the problems created by the presence of underground railway tunnels, poor ground, the depressed motorway profile and the need to minimize tidal effect. After a general introduction the author discusses design criteria and the choice of a suitable route which passed under the underground railway. This includes a discussion of the factors which led to the type and method of construction used. The next part of the article is concerned with the actual construction work, and includes details of the equipment used which included a stelmo shield in the soft ground tunnel and of the tunnel lining. It also includes information relating the blasting methods that were used and the laying and backfilling of the pipes which involved the use of an aliva 300 concrete placing machine. Reference is made to the caulking of joints which was carried out to overcome the problem of containing the compressed air used in the construction in the sheet pile shafts and at the junction with the air deck. /TRRL/