Recent projects that have benefited from early collaboration with Charcon, to determine the most cost effective solutions for segmental linings, include the UK’s Lewes Combined Sewer Overflow (CSO) project with the Black & Veatch/Costain JV for client Southern Water and the Moorhouse draft relief shaft with Skanska (see p47).
The Lewes CSO, in the south-east of England, required new Smoothbore shaft linings of 4.2m and 5.2m internal diameter to be designed and manufactured, to deal with difficult ground conditions. The solution incorporated segments with increased thickness, “soft eye” segments for pipejack access and recessed segments to provide shear connection to base slabs to resist flotation.
A new Smoothbore shaft lining of 8.2m internal diameter was also developed for the Moorhouse shaft, in London, which was required to accommodate anticipated ground movement resulting from future planned Crossrail construction works. Special features incorporated in the linings included facilities for secondary grouting, dewatering, locating dowels and slip membrane on horizontal joints.
As with all of Charcon Tunnels’ Smoothbore shaft linings, the segments were supplied with factory fitted EPDM gaskets to provide immediate sealing of all joint faces when ring building. Segments can be manufactured using conventional reinforcement or steel or plastic fibres.
Tel: +44 1623 754493
Email: charcon@tarmac.co.uk
