Mott MacDonald, Costain, Vinci Construction Grands Projets and Bachy Soletanche

This award recognises a hi-tech advancement or concept that has helped a company improve its performance or delivery of a specific challenging element of a project, between January 2022 and January 2023. This category is not aimed at projects that have achieved overall excellence – such projects should be entered into one of the six project categories. The entrant may have achieved technical excellence through producing a new approach to analysis or design, advanced techniques or procedures during design or delivery and/or working with its customers to improve delivery of a specific part of a project through technical refinement. An entry should be for a single technical advance or development applied to a specific part of a project. Developments applied to a number of projects may be better placed in the Digital Innovation or Equipment Innovation categories. The geotechnical work on the project presented must be completed at the time of the submission.

Thames Tideway Chambers Wharf Shaft Secondary Lining Pressurisation

The Thames Tideway project has sustainability embedded throughout the project delivery. At Chambers Wharf, the huge 70m deep, 25 m diameter shaft needed an inner secondary lining to contain the vast volumes of effluent safety. The pressures exerted meant the liner would have to be very robust. To improve the design efficiency, safety, sustainability and cost, an intensely collaborative VE exercise was undertaken between designer, constructor, and client. In a step change to previously applied techniques, the solution was to put the liner into permanent compression by pressurizing it via an external annulus, filled first with water and then concrete, ensuring pressure was constantly applied before being locked in. We were literally and metaphorically, squeezing all we could out of the design. In the liner a 40% reduction, 370 tonnes, was achieved in the reinforcement using this water / concrete pressurized technique, with an approximate carbon saving of 280 tonnes.