Keller Divisions Join Forces | Piling Contractor | Vibro | Keller UK

BLOG: Keller divisions join forces to offer the whole solution

Keller UK is always looking for opportunities to offer multi-layered solution to clients via its four divisions. When we were approached by a construction firm about the best way to develop a brownfield site we came up with three different solutions – and saved them money on their original plan.

The developers of Epping Retail Park - a brownfield site in Essex - had come up with a plan to widen and raise the land to increase the number of units that could be built on it.

This posed an interesting geotechnical challenge, as the plan included placing a new embankment on top of an existing one, placing additional loads on the existing fill material, inducing settlement and presenting potential stability issues.

Initially the thinking and early advice provided to consulting engineers, Pinnacle, was that the new structure should be piled.

They consulted Keller and having worked in the area often over a number of years, our engineers had other ideas and came up with another design and build option.

They looked at the soils beneath the walls in trial pits and concluded that the soft clays were not as soft as reported in an old Site Investigation report. Their attention turned to whether or not a cheaper and quicker ground treatment solution could be offered for the structures.

David Whyte, Keller UK’s ground improvement estimating manager, spent a whole day on site and concluded that the soils were treatable provided bottom feed vibro stone columns were was used in the softest areas.

David’s team then set about offering the team a value engineered solution removing the need for precast piling and winning the contract.

“Ironically, we were under consideration for the piling but it’s always nice when you can introduce a time and cost saving to a project”, David said.

While the ground improvement team were presenting their plans, another of Keller’s UK companies - Phi Group - were solving the issue of retaining the new embankment with one of their retaining wall systems and how to support that wall.

Engineers at Phi proposed a combination of flexible Textomur and Titan walls. These system can accommodate some settlement of the base although it was decided to support the base on vibro stone columns.

“This is exactly the type of project where Phi and Keller working together can call on their joint expertise and wide range of tools bringing the best solution to the project, “ said Derek Taylor, Keller UK’s Business Development Director.

“In this case, the two systems were mutually dependent and by one company offering the whole solution meant that we were able to minimise risk, programme and cost for, main contractor, McLaughlin and Harvey, the engineer, Pinnacle and the client. “

The first structure to be built was an 81m long Textomur reinforced soil slope constructed at 65 degrees to a maximum height of 6.6m.

Textomur works by reinforced soil material placed and compacted around layers of geogrid reinforcement to form the reinforced soil mass which acts as a gravity structure.

The second structure constructed was a 119m long Titan modular wall. The Titan wall’s maximum retained height was 6.30m and it works on exactly the same principle as the Textomur, but uses steel ladder reinforcement as opposed to geogrid and a high quality split faced block for the facing.

A total of 2500 vibro stone columns up to 6m in depth were installed beneath the retail units over a four-week period. Importantly the use of a vibro approach meant that McLaughlin and Harvey were able to form foundation pads on the treatment soon after it was installed, saving time on their programme

So, all in all, a win-win for the client and Keller.




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