Issue 12 - Spring 2007

Heathrow Job Takes Off with Help from Pennine

We overcame difficult ground conditions and the risk of contamination to save our client's time and money at the site of 16 new warehouse units near Heathrow Airport.

Previously used as railway sidings and a crane hire depot, the site in Colnbrook had varying ground conditions ranging from soft peat to stiff clay, along with a water-bearing gravel aquifer and limited hydrocarbon contamination.

Initially, main contractor SDC Builders Ltd had planned to use continuous flight auger piling to support the new buildings.

However this more expensive option would have encountered problems in penetrating the coarse fill materials and generated significant amounts of contaminated spoil which would have involved disposal costs.

Our team devised an alternative combination of three different treatment solutions. Vibro concrete columns (VCCs) were used as shallow piles in some areas, and in other areas vibro stone columns (VSCs) were used to improve the soils to achieve the required load bearing capacity of 125kN/m2.

VSCs were also constructed with basal concrete plugs to avoid the possibility of stone columns forming drainage paths allowing contaminants to penetrate the gravel aquifer.

The £120,000 contract was completed on time and to budget, with substantial cost and efficiency savings for the client.

Heathrow Job Takes Off with Help from Pennine Pennine Settles Things Down on the Palm Pennine Wins Bumper M6 Link Contract Pennine Prepares For a Night at the Oscars A Fond Farewell and a Warm Welcome

Pennine at work in Colnbrook

Pennine Settles Things Down on the Palm

Our position as a world leader in ground improvement systems for marine applications has once again been highlighted. Managing seismic risk for a multi-billion pound development in the wealthy Arab emirate of Dubai was a land mark contract for us.

Vibro-compaction (VC) work, which prevents liquefaction in the event of an earthquake, is taking place on palm Jumeirah, the smallest of three colossal man-made palm-shaped islands being built off Dubai's coastline using dredged material.

Arabian developer Nakheel has more than £30bn of business and holiday construction projects under development on the palm, which covers about 56ha of land with a coastline of 78km. Construction on the palm is approximately a year behind schedule, partly due to subsidence.

After successfully completing work on the fronds of the palm, Pennine was called on to compact the ground at two points on the rock armoured crescent that protects the fronds.

Two Pennine rigs worked around the clock across an area of 45,000m2 at depths up to 18m down to the sea bed. A vibro-flot, aided by water jets, penetrated the ground, re-arranging and compacting the sand particles into a dense state. More sand was also introduced to the tube at the surface and gradually released as the vibrating poker withdrew in 0.5m to 1m lifts.

Nakheel wants the ground to stand up to a magnitude six earthquake with a peak ground acceleration of 0.15g at the rock head (which in this case would be 0.2g at the surface). This means the treated ground needs to settle to five per cent of the total treated depth, but Pennine says it achieved up to ten per cent.

Palm Jumeirah is the smallest of three colossal man-made palm shaped islands

Pennine Wins Bumper M6 Link Contract

Pennine has started work on one of its biggest ever contracts – to prepare ground for the new M6 motorway link at Carlisle.

Our team of specialists moved on site at the end of February after we were awarded the prestigious £1.4m contract by main contractor Carillion.

Over the next 20 weeks, the 24-man team will use three rigs to insert no fewer than 4,395 vibro concrete columns (VCCs) with enlarged heads over an area 12,484m2.

The VCCs are necessary to strengthen the load bearing capacity of former swamp land, comprising soft silt, peat and gravel, which has been used more recently for farming.

Work on the main road structure for the six-lane M6 link and an adjoining four-lane A road has commenced with overall completion scheduled for winter of 2008.

The contract win marks the start of a busy year for us; we are expanding the South East operation to gear up for major ground engineering opportunities posed by both the Thames Gateway development and the 2012 Olympics.

The map highlights the section of A
road that we are working on

Pennine Prepares For a Night at the Oscars

We have once again been short-listed for one of the Construction Industry's most prestigious awards.

The “Specialists in Construction” 2007 awards are being held on the 10th May at the London Hilton Park Lane Hotel and we are hoping to pick up the award for “Ground Engineering Specialist of the Year”.

The awards, organised by Construction News magazine, aim to highlight the critical role played by specialist contractors in the Construction Industry.

Managing director Arwel Williams said: "The Ground Engineering Specialist category is so fiercely contested we're delighted to have been short-listed. Specialist contractors play such an important part in the Construction Industry supply chain and it's great to see recognition being given.”

In selecting the winner of the Ground Engineering Specialist category the panel of judges will analyse the company's performance in the past calendar year, consider how it has satisfied customers, how well the business was run and look at the company's training and safety policies.

A Fond Farewell and a Warm Welcome

We would like to wish Stan Mimms good luck in his new role as regional manager for our Dubai operations. The former UK marketing manager will relocate to Dubai and take-up the position at the beginning of May.

Stan will work with geotechnical engineer Ralph Cook to expand the Dubai office which is based in the Dutco Balfour Beatty building west of the city centre.

In addition to Stan's move, we also have a new recruit at one of our regional offices.

Simon Young joined the team in March as contracts manager for the South West. He has previously worked in the USA and has been in the industry for 15 years.

Simon joins Graham Ellery in our Gloucester office, but will work on major projects throughout the UK. In addition to his UK role Simon will use his knowledge to help Pennine develop a presence in the USA.

If you would like to contact Stan or Simon please use the following email addresses:
stan.mimms@dbbcg.com
simon.young@pennine.co.uk

Stan Mimms, newly appointed
regional manager for Dubai

This email has been sent by Pennine Vibropiling Ltd, registered in England number: 2878498 at Pavilion C2, Ashwood Park, Ashwood Way, Basingstoke, Hampshire, RG23 8BG.

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