We have made the GE Awards 2023 Shortlist
Deep Soil Mixing Ltd has shortlisted for the Ground Engineering awards 2023.
The awards which are now in their 15th year and the winners will be announced at a gala evening at the JW Marriott Grosvenor House Hotel in London, on the 12th July 2023.
We have been shortlisted in the category:
UK Project with a geotechnical value up to £500K
Along with our project partners, JBA Bentley, we entered the Clementhorpe Flood Alleviation scheme, into this category.
York has been prone to flooding and in 2015, Government allocated £45m to the Environment Agency (EA) to protect 2,000 homes in the city, 135 of which in the Cell B8 Clementhorpe scheme.
In Jan 2023 river levels rose but the Clementhorpe area was saved from flooding due to a £7.7m flood defence scheme which completed in 2022. A major part of this included the innovative use of Deep Soil Mixing’s soil mixed underground seepage mitigation barrier, a solution that has not been used before for flood defence schemes in the UK.
The use of soil mixing on this project is a prime example of how innovation in ground engineering, sustainability and value engineering together with collaborative working with stakeholders including the EA, the Local Authority and Contractors JBA Bentley can be beneficial to not only one project but also has the potential to change flood defence work going forward.
JBA Bentley were initially looking at using secant piled walls, but this was cost prohibitive for the project. Deep Soil Mixing were approached and in collaboration with JBA Bentley an underground seepage mitigation barrier using ‘soil mixing’ was proposed. This was designed to make the ground semi-impermeable. By using soil mixing, our solution was both sustainable and cost-efficient.
Our soil mixing solution comprised a cut-off wall constructed with secant columns 5-6metres below ground, adjacent to apartments. It created a semi-impermeable barrier underground to stop the flood waters from seeping through the ground and passing underneath the above-ground flood defences.
Working with JBA Bentley prior to starting on site, Deep Soil Mixing conducted trials to find the right mix and quantity of binder and soil, to ensure specific compressive strength qualities and semi-impermeability were achieved.
Spending time with the Bentley’s prior to start on site and liaising with the Environment Agency, local councillors and residents to keep them abreast of the project proved invaluable.
The soil mixing solution implemented by Deep Soil Mixing was designed to a critical permeability factor to allow landside water to mitigate back to the river from the surrounds whilst at the same time not allowing flood waters into the homes. This involved mixing a binder into the existing ground using our double rotary mixing head mounted onto a rig to create an underground flood defence, 240 metres long and up to 6 metres deep.
The purpose-built double rotary mixing head has twin paddles that move in opposite directions to achieve the greatest soil distribution as the materials are mixed. Improving the soil mixing process enabled the mix designs to be more finely tuned and accurate, increasing both efficiency and costs benefits for the client over the industry norm of a single auger mixing head.
Unlike piling, soil mixing has zero vibration which given the close working proximity of homes combined with reduced material deliveries and plant movements minimised disruption to the homes. Utilising the existing ground also reduced disposal of material off site, reduced import and significantly lowered the carbon footprint.
Rob Culledge, JBA Bentley Contracts Manager, said,
“Deep Soil Mixing collaboratively consulted during the design phase, going above and beyond requirements, carrying out numerous site visits in advance of the works, to plan in detail the temporary works, programme of installation and health and safety requirements all resulting in the scheme being delivered safely, ahead of programme and to budget.”
Colin Critchlow Associate Director at Deep Soil Mixing Ltd, comments:
“To be shortlisted for this year’s awards is fantastic recognition of the work we have undertaken at York in partnership with JBA Bentley and a great endorsement of the hard work by the Deep Soil Mixing team. Plus, recognition for innovative ground engineering solutions like soil mixing. We are now looking forward to the awards evening in July.”
