Parliament Square gets upgrade
Custom-designed centrifugal cast GRP pipes have been used to reline a 250m section of damaged brick sewer which runs from Parliament Square in Central London to the Victoria Embankment, alongside the River Thames.
Once the pipes were secure, the annulus between the liner and old brickwork was filled with grout.
Johnston Pipes' business development director, David Smoker said, 'Durability was a key requirement in the choice of pipeline material used for this project. The contractors needed a liner which was able to withstand the imposed load of traffic in the area.'
Flexibility was another key point in Johnston's favour as GRP pipe is manufactured in sections which makes it easy to assemble underground.
The company's GRP pipe has also been used to answer a vertical challenge on a major sewer relief tunnel project on the river Orwell in the east of England for Anglian Water.
Lightweight pipes, capable of withstanding the aggressive nature of sewage, were used by Contractor AMEC Tunnelling to line five vertical drop shafts of up to 48m deep which connect the existing sewer network to the relief tunnel. The pipes were moved from horizontal to vertical in segments using purpose-built lifting and support clamps.
Specially designed trestles were also used at both sides of the vertical shaft entry to support base, intermediate and upper pipes throughout the lifting and placing operation.
To secure and joint the pipes, mechanical harness rings were used as they were lowered down the shaft. Harness ring tie rods were positioned and torqued to make the joint.
The joining sequence was repeated adding 6m lengths of pipe until the shaft bottom was reached.