VICTORIAN SEWERS SAVED FROM NEAR COLLAPSE
In partnership with lining specialist, Insituform Technologies, civil engineers GFTomlinsonandSons have completed a major rehabilitation of Grade 5 sewers in Leamington for Severn Trent Water. Around 2,100 metres of dilapidated sewers have been restored to Grade 2 condition extending their working life by at least 50 years.
In partnership with lining specialist, Insituform Technologies, civil engineers GFTomlinsonandSons have completed a major rehabilitation of Grade 5 sewers in Leamington for Severn Trent Water. Around 2,100 metres of dilapidated sewers have been restored to Grade 2 condition extending their working life by at least 50 years.
The contract was undertaken against a background of technical difficulties. In some cases the brick sewers were badly deformed, in others structural defects the sewers were causing the leakage of smells and there were also flow obstructions caused by earlier patch repairs and tree roots. At one point, a sewer passed below a corner of a row of houses. Conventional open cut was out of the question in this case while large scale trenching would have caused severe disruption and environmental damage elsewhere.
The sewers dated mostly from Victorian times. In many cases these were brick eggs varying from 450 mm x 375 mm to 900 mm x 600 mm. In one location the sewer invert was channelled into the bedrock with a brick arch above. The sewers were all located beneath roads at depths of up to 5.2 metres from the surface.
Within the contract, lining accounted for approximately 400,000. Insituform were responsible for all lining work with Tomlinson's undertaking enabling works, manhole reconstruction, open cut repairs where required and project management. Much of the programme was undertaken during periods of substantial rainfall, requiring major over pumping operations at times.
In addition to standard CIPP lining, Insituform can also offer systems for restoration of large diameter pipes, pressure resistant systems and linings for acidic or other aggressive effluents. Thermopipe, a flexible lining system for both sewage and potable water pressure pipes is also available. The company frequently works in partnership with specialist civil engineering contractors to provide long life, low impact solutions to pipework remediation.
The contract has proven a triple win for the community, utility and contractors. Disruption to people and the environment has been minimal. Severn Trent have obtained a cost effective total solution by employing the combined expertise of Insituform in rehabilitation and the civil engineering skills of G F Tomlinson. In addition to reducing the total project cost, simplifying the bid process also saved valuable time for Severn Trent engineers.
High resolution pictures for this text are on the web at www.ainsmag.co.uk/in198/3258in1a.htm
|
