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Featured Projects

Our Featured Projects cover the length of the United Kingdom and show a wide range of the specialist areas in which we work.

See features on a range of our past projects below...

Beetham Hilton, Manchester

Terrain Geotechnical Consultants Limited were awarded the contract for the design of a contiguous bored pile wall for basement retention for this prestigious 47 storey residential/hotel building.

We provided the design for temporary and permanent retention to the surrounding ground utilising a contiguous bored pile wall of both 600 and 750 mm diameter piles.  The wall was up to 9 metres in cantilever using 600 mm diameter piles, elsewhere the wall was propped off the capping beam for 11 metres retained adopting 750 mm diameter piles.  The piles were installed using a Continuous Flight Auger (CFA) piling rig (a Soilmec CM70) capable of penetrating the weak to moderately strong underlying sandstone.

The design was particularly complex due to the deep dig, a temporary tower crane also partially supported on the wall piles and the requirement to adopt a cantilever solution where possible.  Our extensive experience with this type of construction in Manchester and elsewhere assisted our client to win this contract over other competing bids.

Blackfriars Station, London

Terrain Geotechnical Consultants Limited were awarded the contract for the design of self drilled micropiles (including raked piles) for the foundations of a temporary staircase for the upgrading of Blackfriars Station in London.

 

The site posed many challenges which were successfully overcome to deliver the desired outcome within strict time constraints.

The site had extremely limited access due to its location adjacent to the public footpath next to the River Thames.

 

The piling solution provided had to take account of the sensitive retaining structures (and the historic Blackfriars Bridge), proximity of the public, environmental implications of the riverside location and the lack of road access to the site.

 

We also tested the installed piles to verify the design.

Foel Goch Landslip, Rhigos Road, Rhondda Valley

Terrain Geotechnical Consultants Ltd. were appointed to undertake a condition survey followed by lift off testing of 60 strand anchors at this former landslip at the heart of the Rhondda Valley on the A4061 Rhigos Road near Treherbert.

 

The anchors were installed in 1991 to stabilise the A4061 following a landslip.

Swiss Centre, Leicester Square, London

Terrain Geotechnical Consultants Limited were awarded the contract for the design of 282 bearing piles as part of the redevelopment of an existing site in Leicester Square.

 

The development was to take place on the site of a demolished building with piling to be taken from the remaining basement slab.

 

We proposed to use 450mm diameter augered piles into the London Clay, however due to the close proximity of the London underground below the site, it was necessary in  some areas to reduce the effects of skin friction in the vicinity of the tunnel and here piles were sleeved over the top 10m.

 

Windmill Shopping Centre, Widnes

It was proposed to construct a new shopping park at Widnes, as part of the construction Terrain Geotechnical Consultants Ltd (TGCL) were appointed to design an embedded retaining wall. It was proposed to construct a secant bored pile wall using 500mm diameter continuous flight auger (CFA) bored piles at 700mm centres, retaining a height in excess of 5m.

The sequence of works outlined by the main contractor indicated that the wall would be in cantilever for an extended period of 13 months before being propped by the floor slabs. The retained cohesive material would potentially tend towards the drained condition over this period and would normally require temporary propping. Due to the length of time and the large scale of the project temporary propping was prohibitively expensive.  Longer cantilever piles could have been installed designed for the drained condition but again at considerable additional expense.  As a way forward we suggested the option of using the observational method as outlined in CIRIA R185.

Monitoring was carried out at regular intervals using accurate survey methods, the wall displacements observed from the monitoring were compared with displacements predicted using PLAXIS finite element analysis. Following CIRIA R185 a traffic light system of trigger levels was derived, each level passed resulting in an action, using this method it was possible to monitor the displacements and only prop the wall if an appropriate trigger level was breached. The wall behaved as predicted by PLAXIS and by using trigger levels it was possible to reduce the frequency of monitoring with the option to increase monitoring should a trigger level be breached.

The use of the observational method at this site resulted in a successful bid for our client with a considerable saving for the ultimate client and elimination of disruption to the building programme.