As part of a £5million investment from the European Union Water Directive to improve bathing water quality in Torbay, Alan Auld Engineering (AAE) were responsible for the detailed design of a 20m ID segmental lined shaft to increase flood water storage capacity of the sewer network at Torquay. The shaft was constructed as a caisson through saturated clay sands, where ground water fluctuated due to the flood and ebb of the tide. As part of the shaft design AAE designed the cover slab with beams supported on to a central wet-well, we t-well forms part of the flushing system of the tank. Temporary works design to enable the construction of these types of shaft forms a large part of design, these include temporary buoyancy conditions in the design of the base slab to enable construction in stages when there are large volume concrete pours.
Further points of interest on this project included the use of the shaft as part of a search and rescue undertaken by Torquay Fire Station and a specialist rescue team based in Plymouth.