Mining; more than just coal!

Intégrale are frequently asked to complete pre-development Coal Mining Risk Assessments and Coal Authority compliant Ground Investigations. Whilst the history of British coal mining is well known, Britain also has a rich heritage in mining many different minerals and ores.

One recent example involved the collapse of an old and long forgotten shaft within a garden in a village in the Mendips, Somerset. Here, old mining resulted in discrete shafts being sunk to access the calamine/zinc/lead ore below. Just look at the pock-marked surface from a 1946 RAF aerial image; each ‘crater’ is an individual shaft, sometimes taken as deep as 20m!

Here at Intégrale we pride ourselves on understanding the ground conditions. This allows our clients to develop the most appropriate technical and cost-effective solution.
Image courtesy of  https://www.somersetheritage.org.uk/

Power station to be redeveloped by Oxford University

The University of Oxford have been granted planning permission to redevelop a former coal and oil fuelled power station on the banks of the River Thames. The new development will create a Global Leadership Centre to include teaching, services and residential accommodation for the world renowned Saïd Business School.

Intégrale were asked to complete several stages of investigation due to the site’s complex internal layout and the requirement of an Environment Agency Licence to investigate within 8m of the River Thames. Intégrale utilised Ground Penetrating Radar (GPR) together with historical maps and records to carry out geotechnical and contaminated land investigations to assist the developer with foundation design and potential site remediation. The development is ongoing and Intégrale will continue to be involved in further phases of investigation.

2015 – Remediating Historic Mill Complex

Freshford Mill, Bath

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Remediation work stopped at this site in 2008 when the previous developers went into liquidation.  Integrale completed supplementary validation investigation and co-ordinated specialist groundwater remediation of the remnant hydrocarbon plume, design of new soils cover and hotspot clearance to help realise the full potential of this beautiful riverside location.

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2014 – Delivering Rapid Advice

Wroughton Airfield Solar Park

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One of the largest renewable energy facilities (50 MW) in the UK, it has been in development since 2012; Intégrale completed the Geo Desk Study and Environmental Impact Statement in 2013. Being in an AONB, English Heritage objected, and planning was delayed until March 2015.

Intégrale rapidly completed the Ground Investigation and Remedial Method Statement by mid-summer allowing completion of the c. 90 acres of photovoltaic arrays by March 2016, generating enough power for 15,000+ homes.

2013 – Presenting Hydro and Enviro Advice, Asbestos Landfill

Advising Stowey Sutton Action Group (SSAG)

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At Intégrale, we take our professional responsibility and knowledge very seriously……. to the extent that we are willing to work…gratis…. for local action groups with valid concerns.

This quarry, located adjacent to Chew Valley Lake, has been a site of contention for six years, when permission was granted for asbestos disposal. Residents, supported by Intégrale, gained national attention through a series of high-profile appeals.

In 2013, the Planning Inspector ruled that the quarry could not be used as landfill for stable non-reactive hazardous waste; it posed a risk to residents and the reservoir. SSAG have monitored the quarry since and raised suspicions about the waste arriving. In late 2016, the Environment Agency suspended the permit for even controlled waste disposal .

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2012 – Founding New Buildings on Gulled Strata

University of Bath and University of Bristol

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Both University campuses pose inherent foundation difficulties, demonstrated by more than 20 specific projects completed by Intégrale. The University of Bristol dominates a hillside formed of interbedded sandstone and mudstone, with an unfavourable bedding dip! Stabilisation frequently requires shear-key piles and ground anchors.

The University of Bath, at the crest of a plateau overlooking an unstable hillside, suffers from cambered and gulled limestone. Site specific ground conditions often require plain slab/stiffened edge rafts, not needing a high degree of stiffness. Slab and beam/piled rafts can be appropriate at more artificial locations.

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2011 – Developing Unusual Foundations

Legoland 4, Gunzberg, Germany

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Assessing ground investigations, then optimising appropriate foundations for theme park rides and entertainment facilities with unusual static and dynamic spatial loading.  Advising on extent of lime and cement stabilisation of largest WWII former armaments and ordnance storage complex, concurrent with UXO clearance operations.

2010 – Maintaining Ongoing Stability

Ulwell Reservoir, Swanage

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Access to this elevated site is extremely difficult. Signs of superficial slippage in 2000, triggered boreholes investigation and slope analysis; could there be a catastrophic leakage of water? Should the site be abandoned and relocated? An older reservoir at a lower elevation had been demolished.

We concluded the reservoir was securely founded into Chalk. There was no significant risk of global instability, but the buried concrete structure could become locally exposed.

Reinvestigation in 2012 reached the same conclusion. A programme of localised stability works including ground improvement, soil nailing and drainage, was recommended.

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2009 – Generating Structural Stability

Brimscombe, Stroud, Gloucestershire

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Access to two new houses needed a road in a 3-4m cutting that truncated an old mudslide. Initial investigations by others had resulted in a tragic fatality with Health and Safety lessons for the complete ground engineering industry.

Intégrale’s boreholes revealed a complex Quaternary geology, defining ancient landslips and mudsliding. We completed parametric slope stability analyses and liased with a bored pile contractor to establish a technically and cost effective system of vertical, contiguous bored pile walling. Raking piles were included to resist horizontal loading and overturning.

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2008 – Designing Dredged Sideslopes

Ras Tanura, Saudi Arabia

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Saudi Aramco completed an approach channel, new berths and breakwaters for the Integrated Project.  Integrale provided advice on rock excavation, soils suitability for hydraulic filling and designed the slopes for the navigation channel, including seismic assessment.