I am honoured to have been invited to present at the 16th European Conference on Soil Mechanics and Geotechnical Engineering (ECSMGE), to be held between 13 and 17 September in Edinburgh. I will be presenting my paper ‘Geotechnical Investigation and Design Aspects of Developing Steeply Sloping Landfill Sites’, a paper I produced with my colleague Dr Eric Peng.
Using the Arc Leisure Matlock development (previously known as CALC scheme) as a case study, the paper explains how geotechnical engineers can transform a rubbish dump site into a landmark sport, leisure and tourist attraction. I consider this project as one of my recent career highlights, it posed various geotechnical challenges that tested our geotechnical and civil engineering skills. The project won a number of awards including the Most Sustainable Remediation Project category at the Brownfield Briefing Remediation Innovation Awards and the Most Innovative Design category, Derbyshire Times Business Awards 2011.
The site, a side valley of the River Derwent, was a municipal landfill that was used from the 1950s to 1974, 550m long and had a total height of 37m in 8 platforms separated by steep slopes. Design and construction in steeply sloping landfill sites present significant geotechnical challenges as well as environmental considerations. This is not only related to complex ground conditions in these sites but also in characterising and testing variable landfill materials in the laboratory and insitu, as well as in the application of traditional slope stability, settlement and foundation design methods of analyses.
The challenges included;
- Minimising significant risks to road/railway/river/residential areas/ aquifer.
- Complex site and landfill geology/underground mineworkings.
- Ground investigation techniques to characterise landfill materials.
- Determination of geotechnical design parameters for extremely variable waste materials.
- Shear strength of waste & slope stability methods of analysis/FOS.
- Prediction of ongoing/future settlement & methods of analysis
- Foundations for buildings (piling through complex ground conditions/aggressive ground/groundwater for concrete).
- Car park areas; flexible design for future settlement/strict settlement criteria for disabled car parking.
- Design of piled wall to retain building platforms.
- Gas emissions/economic off site disposal of surplus waste.
- Dealing with environmental issues (badgers, bats, protected trees, Japanese knotweed)
- Design of (contamination) remediation strategy under strict UK legislation without compromising slope stability / settlement.
The paper explains how we overcame these challenges. I had the pleasure attending the official opening of the leisure centre by Lord Sebastian Coe in 2011. Thinking back to how the site was when we started the project and the transformation it went through was a very proud day for a Geotechnical Engineer.