Complex geometry at Tideway’s Heathwall Pumping Station site

A multidisciplinary team of experts have come together to undertake complex reinforced concrete works at Tideway’s Heathwall Pumping Station site.

A geometric reinforcement cage is being installed at the junction where sewage will enter the main shaft from the smaller interception shaft. At peak flow, this junction can see up to 12m³ of water per second, hence the importance of the steel reinforcement to increase the overall strength of the concrete.

The reinforcements is tied to form the circular shape of the tunnel, but it also requires a transition to a rectangular shape for the vortex generator which is immediately downstream.

The work has involved a great deal of planning and input; designers have created different sets of drawings for shape, waterproofing and reinforcement design and senior engineers have used these to establish a safe, high quality and efficient construction methodology. A team of supervisors, steel fixers and carpenters have then turned these plans into reality.

Alex Alchin, Project Manager for Tideway’s Heathwall Pumping Station site said, ‘the best laid plans can be made for this type of work, but it is highly dependent on the skill and experience of the steel fixing operatives. It is a very specialist trade to read and understand reinforcement drawings and then tie all the steel in the correct order to from the correct shape. The tradespersons are the real heroes of this work’.

Once the reinforcements have passed quality control the next stage will be for carpenters to install a temporary mould into which concrete will be poured and allowed to set. This is just one of four similar portal structures at the Heathwall site alone.