Digging deep - the latest foundations equipment and techniques

The latest foundation equipment and techniques are more environmentally friendly and technologically sophisticated allowing for increased productivity on challenging construction sites.

Enhancing the productivity and environmental friendliness of foundation equipment is a top priority for manufacturers in this specialist, but highly competitive market.

The European construction market is undergoing economical and social change and manufacturers must respond to this by developing new technologies and techniques.

Speaking to CE, Ari Kuikka, sales, marketing and service director for Junttan said, "The key things are productivity and environmental friendliness. Companies want to be more productive and they are willing to buy machines which help them to be more efficient in the market."

Heightening productivity is even more vital as construction projects become more complicated and take place in more diverse locations.

Jon Chevin, overseas contracts manager for UK-based Pennine, part of Balfour Beatty Ground Engineering, said the company has trained Spanish rig drivers to increase productivity at a foundation project, which is taking place at the Xita dock in the Port of Valencia. Pennine is working with Spanish contractor Geocisa to install 8500 stone columns in the ground in preparation for the construction of a giant warehouse that will house coal clinker on a platform next to the dock. The warehouse will shelter the coal clinker and prevent coal dust clouds from polluting the surrounding area.

Techniques

Pennine is using a ‘wet top-feed vibroflot' technique to construct the 8500 stone columns required to support the warehouse. This involves plunging a torpedo-shaped vibrating poker (vibroflot) into the soil.

As the vibroflot creates a hole in the ground, stone is fed from the top to create a column of stone, which is then compacted by the vibroflot. The operation is repeated in stages until a stone column is formed up to the surface and compacted to the required pressure.

"The success of the technique is dependent on the soil type as the vibroflot will not get through ground conditions with a standard penetration test value of 20 or so. Fortunately the soil in Valencia, which is mainly sand and silt, lends itself well to this technique," Mr Chevin said.

Elsewhere, a new technique for strengthening soft soils - in this case a peat bog at the site of a high-speed railway line in Finland - was used by Allu Finland so that large piling rigs could gain access to the site. The Finnish company's mass stabilisation technique is based on a separate mixing unit and a binder storage and feeding tank, which is connected to an excavator. The method can also be used for processing contaminated material in-situ.

Meanwhile, according to David Redhead, managing director of BSP International, using hydraulic hammers for pile driving is now commonplace in the foundations sector.

"An advantage of a hydraulic hammer is that you have complete control over what happens so you can accurately control the blow rate and the stroke," he said.

Environmental impact

Reducing the impact that foundations equipment has on the environment while retaining the productivity of the machine is vital for manufacturers to gain a competitive edge.

Mr Chevin said the project in Valencia involved a number of processes to make the ground improvement process greener.

"This ranges from recycled stone aggregate to the use of sea water in the ground engineering process," he added. Pennine has also devised a system whereby deposits from the wet top feed process can be recycled for use across the site.

According to Mr Redhead the environment is the biggest challenge for the foundations industry. "But a lot of work takes place off-shore or not in an area where there is an environmentally sensitive issue," he said.

He added, "A piling hammer will make quite a bit of noise and one of the trends is moving towards keeping hammers quiet. This is something that everyone is very much attacking."

The easiest way to reduce noise on a hammer is to put a shroud around it but the size of it can reduce visibility Mr Redhead said.

Mr Kuikka echoed this sentiment and said, "Noise levels have always been discussed when talking about pile driving. Our hammers have been developed to reduce the noise and have certain features that help to do this. The noise is a bit different when you compare it to pile drilling rigs - they also make noise but it's steadier - at the same level almost all the time. But they also make a noise when the steel hits against the steel."

He added a combination of factors drive new product development but the main focus is to make more productive machines that also take into account safety and environmental regulations.

Market

Foundation equipment manufacturers say they are witnessing changes in the European market due to increasing infrastructure projects in emerging markets and the uncertain state of the global economy.

Mr Kuikka said, "The foundations market has been very good for us in the last 12 months up until the last few months when we have seen the market become more careful in making investments because of the economic situation - there's a lot of uncertainty about the future development of this."

The market has been divided in the last year according to Junttan with some markets remaining strong while others are seeing sales decline. Mr Kuikka said the 2012

Olympic Games is helping to buoy the UK market and the Scandinavian market has also been positive during the last 12 months, "but of course the private house building market is decreasing and we can see that in our sales," he added.

Federico Pagliacci, general manager for Soilmec, told CE the European market is currently undergoing very rapid change, but he added the company predicts a positive forecast for the next three years on the back of the large infrastructure projects taking place across Europe and the Commonwealth of Independent State (CIS) countries.

Product development and drivers

According to Mr Kuikka there are roughly two main techniques used in the foundations business - pile drilling and pile driving. He added Junttan has calculated that when pile driving less energy is needed to get the pile into the ground compared to pile drilling. Therefore, he said less fuel is used and so pile driving is better for the environment.

"We are manufacturing both kind of machines but we sell more pile driving machines than pile drilling machines," he added.

Another trend is to use bigger hammers and bigger piles and Junttan has recognised this by increasing the size of its hydraulic hammers with the introduction of the 25 tonne HHK25S. Junttan is also developing new measuring and information systems to be integrated into its foundation equipment in the near future.

Mr Kuikka said, "I see that the information and measuring systems maybe very important parts of the machine. The information systems can help companies to be more effective and productive. Improved planning and communication helps manufacturers to provide a better service and this is one of the important things for the customer at the moment."

He added part of the measuring system is integrated into the information system in order that the operator can send the pile data to the office where a record of the piles that have been made can be seen.

"There are a lot of different components that are put together in the system so the machine can be used in an improved and more effective way on the jobsite," Mr Kuikka said.

Meanwhile, Mr Pagliacci said customers still choose bored pile rigs as their preferred equipment. He added Soilmec expects continuous flight auger (CFA) to become the main technology in emerging European markets.

Soilmec is developing two products for the European market including the Turbojet technique, a method for making soil columns that are consolidated by a mechanical tool and hydraulic high-pressure cement mixture jets.

The company is also developing large diameter cased augered piles. These are to be used as an alternative to the traditional method with temporary casing, but with the advantage of quicker emptying. This is due to the use of a continuous auger instead of a bucket, the company stated.

Elsewhere, Bauer's cutter soil mixing method is one of the company's most significant developments, according to Christian Gress, Bauer's executive director.

"This is where we apply the existing technology of excavating a trench for cut off walls or structural walls and combine it with the idea of mixing the existing soil. It's a technology using our slurry wall cutter and combing it with the soil mixing method," he said.

Future challenges

Foundation equipment customers are becoming more demanding as construction sites become more challenging. It is therefore essential that manufacturers continue to develop new products and services that enable them to differentiate themselves in the market.

Mr Pagliacci said the biggest challenge will be supplying products which meet the needs of the customers.

"The challenge will be to supply not only an excavation rig, but a complete and articulated service which must also cover the training of our customers' personnel," he added.

Mr Kuikka said the uncertain global economic situation is the biggest challenge for the foundations industry. He added overall, the European market will grow slowly in the next 12 months, although some areas will grow faster than others.

Mr Pagliacci said, "With regard to the next 12 months, the trend will be surely positive, aligned with that of the past trading years."