Sheet Piles to Provide Watertight Emergency Reservoir Repair
Sheet Piling (UK) Ltd, has recently been asked to carry out emergency repair work at the Staines Reservoir in Surrey. We are working on behalf of Costain Atkins Black and Veatch (CABV) JV and the contractor’s client, Thames Water, with the aim of delivering a watertight solution under emergency conditions.
This is the second such reservoir repair job that Sheet Piling (UK) Ltd has handled for CABV JV, with the first having been at Island Barns Reservoir, where we demonstrated the value of a contiguous sheet pile wall in 2017. We are now working to the same successful sheet piling design and installation blueprint, to carry out these rapidly required remedial works in Staines.
How sheet piles assist emergency reservoir repair works
Our sheet pile cut-off wall will prevent the current leakage of water through the reservoir’s core. It will form a impermeable steel sheet pile barrier and consist of 18-metre-long Arcelormittal PU32 sheet piles. Using our Giken F201 Silent Piling Press, we will install these sheet piles through the existing reservoir embankment’s core.
The approach will be to feed sheet piles from a purposely designed and constructed floating barge, which we will build from Unifloat Pontoons. This will give us a means to get both sheet piling equipment and the sheet piles themselves across the water and then use the barge as a lifting platform from which the steel Arcelormittal sheet piles can be fed to the walking Giken press.
Our floating sheet pile installation solution
Getting plant on to the water requires the building of a temporary jetty, which will be a rectangular cofferdam of sheet piles, filled with graded granular material. This will enable us to get an 80Te crane on to the floating structure and float it out to the required installation location. Once there, it will assist the work of the low-impact Giken press on the dam’s crest.
The process impacts on the existing and somewhat fragile structure to a far lesser degree than the installation of a cement-bentonite cut-off wall would do. That would require extensive enabling works – not required by our specified steel sheet piling solution, which is focused on protecting the dam from further damage.
Minimising environmental impacts
We are also, as always, mindful of environmental impacts and our sheet piling works will not pollute the water with slurry, which could arise through the creation of spoils and arisings in a cement wall project. All we need is a shallow trench in which the walking press-in sheet piling machinery can operate.
Once the sheet pile wall installation is completed, we will fully reinstate the clay core, after conducting pitch, tenacity and elongation tests.
Victorian infrastructure repairs
The work at Staines is anticipated to take our Sheet Piling (UK) Ltd team around three months. Luckily, our team members always operate in relative isolation, a good distance apart, so we can comply with the current health regulations in force for emergency and essential key workers.
The steel sheet piles’ design-life is around 100 years, so these repairs will last a long time into the future, ensuring this water supply and leisure facility is safeguarded from any leakage in the area of the works.
It is satisfying to know that we have gained a reputation for outstanding expertise in this type of reservoir wall repair project and that hardwearing steel sheet pile cut-off walls are being recognised for their effectiveness in dam repair work. Whilst this emergency call-up was not expected, we do believe we will handle much more of this type of reservoir repair work in the next few years, as once solid Victorian infrastructure starts to come to the end of its life. If you have such a project, please get in touch.
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Sheet Piling (UK) Limited is one of the UK's leading piling contractors. Owning and operating a comprehensive range of specialist piling equipment Sheet Piling (UK) Ltd also carry extensive stocks of new and used piles enabling rapid reaction to any urgent requirements or emergency situations.