Sure footing for Europe's foundation sector

There is no doubt the last 12 months have been good for foundations contractors and equipment manufacturers alike. Earlier this year foundations contractor Keller announced a record +64% growth in pre-tax profits to UK£ 48,8 million (€ 71,3 million) in 2005 from sales of UK£ 731 million (€ 1,07 billion). ”Last year was an outstanding year and our results reflect an exceptional performance in the US. The Middle East offered some good opportunities and our Asia Pacific market also improved as the year progressed,” said Keller chief executive Justin Atkinson.

Elsewhere, Bauer Maschinen, one of the world's largest foundation equipment manufacturers, has reported record sales in 2005. Speaking at the company's recent open day at its new factory in Schrobenhausen, chairman, Thomas Bauer said the company had seen a rise of +25% in sales during 2005 to € 350 million.

Speaking to CE at the recent Intermat Exhibition in Paris in April, Bauer executive director Christian Gress, said sales have been growing steadily since 1991 and it is a trend he attributes to Bauer's continued investment in research and development.

“The Middle East and North America are the biggest markets for foundations at the moment, but Asia Pacific is also picking up and Europe is doing well too,” said Mr Gress. “We are expecting the market growth seen in 2005 to continue into 2006 and 2007 but maybe at a slightly lower rate.”

According to Mr Gress, growth in 2005 came from both increasing demand and a gain in market share. “We moved to a new factory in Germany 18 months ago to give us extra production capacity and the plant is now operating three shifts to keep pace with demand,” he said.

Mr Gress attributes the growth in demand to Bauer's development of new foundations techniques, such as Cutter Soil Mixing (CSM) and displacement piling. “We launched our first CSM rig in 2003 and the technique is already gaining worldwide acceptance,” he said. “The rig uses cutter heads to displace the soil and mix with slurry to create a diaphragm wall without creating any spoil. It is ideal for urban redevelopment projects or for working on contaminated sites where disposal of spoil can be a real problem.”

Bauer has just launched a new advanced version of the original two head system and the Quattrocutter features four cutting heads, which makes drilling easier and allows the diaphragm walls to be built to greater depths. Customers got a chance to see the rig at the company's recent open day at the new factory in Schrobenhausen.

The first rig to be shown in Europe from its new manufacturing facility in China, the BG 25 C (65 to 70 class), was also at the event and Bauer reports strong interest among the 2000-plus visitors at the event.

Another new CSM rig is Soilmec's CT Jet, which is available in two versions - a rig mounted guided version or a crane mounted suspended model. “The CT Jet is a ground improvement technique that carries out soil mixing with grout under high pressure,” said Soilmec managing director Stefano Cordella. “The system can be used to construct small retaining walls and temporary works, as well as diaphragm walls.”

Finland-based foundations equipment manufacturer Junttan is also reporting strong markets in North America but has also seen demand in Russia grow over the last 12 months. “Demand in China and Eastern Europe is also growing,” said Junttan sales and marketing director Ari Kuikka. “The markets in Australia, South East Asia and South America are smaller but are becoming more important.”

Wind Power

With the high cost of gas and oil driving up domestic and business fuel bills throughout the region, one area currently helping to boost sales and activity is the move towards wind power to generate electricity. However, many sites are in remote locations and often have difficult ground conditions, both of which are providing the foundations industry with new challenges.

Experience gained by Wirth on the Elm Road off-shore wind farm in Wisconsin, US, for which Keller carried out the foundation work, has been put to good use developing foundation equipment for construction of the UK's 10 km² Burbo Offshore Wind Farm on Burbo Bank in Liverpool Bay. Work started in May and is scheduled to finish at the end of August. When complete, the 30 turbines will generate 90 MW, enough power for over 72500 homes.

Each of the 3 MW turbines, which will be fitted with three 45 m fibreglass blades, will be mounted on an 80 m tall tower supported by a steel tube monopile foundation driven 30 m into the seabed. A joint venture of Dutch Drilling Consultant and Mammoet van Oord is using a Wirth PBA 933 pile top drilling rig to carry out reverse circulation drilling (RCD).

The 32 tonne PBA 933 is the largest RCD rig in the world, and has a nominal torque of 330 kNm. The drill string and the Bottom Hole Assembly (BHA) unit, which weighs 85 tonnes, have a total length of 60 m. The drill string consists of 14 flanged airlift drill pipes, each with a nominal width of 300 mm and a length of 3 m. Two drill pipe stabilizers give the upper drill string guidance inside the standpipe and the lower BHA.

The 60 m long drill stem is fitted with a bespoke Wirth drill bit to construct the 4,4 m diameter foundations. The bit plate is fitted with 25 tungsten carbide disc cutters with button bit inserts.

The UK would appear to be a hotbed of wind turbine erection at present. Besides off-shore construction there is also a growing demand for on - shore wind farms. Following on from the successful completion of installing precast concrete piles for its first wind turbine at Reading, UK, Aarsleff Piling is installing 700 piles for three wind farms in East Anglia. The UK£ 400000 (€ 585000) contract will see 22 wind turbines erected at Deeping St Nicholas, Red House Farm and Glass Moor.

According to main contractor McNicholas Construction Services' project manager, Tony Heaney, “The scheme was originally based on bored piling, but Aarsleff suggested the precast concrete driven pile alternative, which was accepted and incorporated into the design by our designer Gifford.”

The largest and longest piles are required at the 12 MW Red House Farm site where Aarsleff is using it's Banut fixed leader rig with a 6 tonne hammer and a Junttan PM20 rig, also equipped with a 6 tonne hammer, to install 36 piles equally spaced on a 13 m diameter pitch for each of the six bases. The 350 mm square section jointed piles are between 18 and 22 m long.

Slightly smaller section and shorter piles were needed at the 16 MW Deeping St Nicholas and 16 MW Glass Moor sites where Aarsleff is installing 32, 300 mm square section piles for each of the 16 bases. All the piles have to cater for cyclical loading ranging from a maximum compressive working load of 630 kN to 160 kN tension. These were produced specifically for the project and contain extra steel reinforcement and earthing strips.

Port Expansion

Infrastructure demands of a different kind have seen the port at Bremerhaven, Germany expand its container terminal from 3200 to 4870 m at a cost of € 500 million.

The contract for the project was awarded to the CT 4 joint venture (JV) - Hochtief, Bilfinger+Berger, Strabag and Gustav W. Rogge. Over 37000 tonnes of steel sheet piles, 10000 tonnes of steel reinforcement, 60000 m³ of concrete and 10 million m³ of sand will be needed to complete this mammoth task.

Construction of the waterside sheet pile wall in the River Weser, which is fully exposed to the tides, represents the most important and complicated phase of the project. For this the JV is using two heavy jack-up platforms, the Odin and the Annegret.

For pile driving from the Odin, which has been specially built for the CT 4 project, the JV is using a Liebherr LR 1280 crawler crane, equipped with a 51 m long, LRH 600 suspension king post and a Dieseko PVE 110 M vibrator providing 225 tonnes of centrifugal force.

The 784 kW PVE 1000 is being used to vibrate 743, 42,3 m long Peiner PSP 1000 to 1016 double sheet piles. With a single pile weighing 25 tonnes a total of 17500 tonnes of piles will be needed.

For the second phase of construction 743 raking piles will be used to absorb the horizontal forces acting on the sheet pile wall. These will be installed from the Annegret, which is equipped with a Liebherr HS 895 HD crawler crane using a 55 m long suspension king post and an IHC S-70 hydraulic hammer.

Over 730 Peiner PS t 600 piles, which weigh 7,2 tonnes and are 45 m long, will be used. In all 5300 tonnes of piles will be needed.

Further complicating the construction process are the enormous loads the quay will be subject to during its operation. The layer of sand on which it will sit is unable to bear these loads so 1380 steel piles will be installed. Up to 34 m long they will be vibrated into the ground at an inclination of 8 in 1 and then driven for the last 5 m.

At this stage construction will use a Liebherr HS 883 HD, with LRH 400 and Mueller MS48 vibrator, a Liebherr HS 895 HD with an LRH 600 and a Menck MHU 150 hydraulic hammer.

Outlook

There is no doubt that Europe's energy requirements, coupled to infrastructure demands, will continue to stimulate the foundations sector. Burgeoning export markets are also helping push up production levels and raise contractors' turnover, while new technologies are helping save time and money on many projects.