The project involved the construction of a single storey building to provide a swimming pool facility in Accrington. The swimming pool was to be of a standard which could be used for competitions.
The ground conditions at the site consisted of mudstone which was encountered at a variable depth beneath the made ground throughout the site. Beneath the swimming pool it was necessary to provide a consistent bearing strata to avoid differential settlement of the pool base, which was overcome by excavating out the rock in places and replacing with a number of layers of compacted engineered fill. All the foundations took the form of mass concrete foundations which were supported on the mudstone.
The superstructure was constructed using a steel framed solution with portal frames clear spanning over the pool. Lateral stability of the structure is provided by a combination of portal action and cross flat bracing. It was necessary to provide hot rolled steel purlins to the roof structure rather than the more typical cold rolled sections due to the aggressive corrosive environment provided by the swimming pool. As a result of this environment it was also necessary to paint all the steelwork including the bolted connections and sag rods with a high specification anti-corrosion paint.
The pool itself was constructed using reinforced concrete with the concrete applied using the Gunite sprayed concrete technique. The concrete was sprayed from nozzles using special plant with the aid of high pressure air and built up using in a number of layers until the required thickness of walls and base had been provided. It was necessary to house a large tank beneath the ground slab as part of the pool water filtration system and consequently this area of the slab took the form of a suspended reinforced slab.