Rugeley Bypass has been an engineering triumph in many ways.

The road has been built at a time of immense challenge for the construction industry globally.

The cost of all large building projects has rocketed in recent years, fuelled by the increased cost of oil and the insatiable demand for raw materials, especially in China.

If the rate of construction inflation is taken into account the cost of Rugeley Bypasss has actually fallen since it was first approved in 2002.

That is in large part due to innovative engineering employed by Staffordshire County Council and contractors Birse and Wrekin Construction.

Bridge construction innovation

One of the major challenges was the building of two bridges to span the railway line supplying Rugeley's massive power station with coal.

Traditional bridge building techniques would have seen the work done over many successive nights.

Mike Hooper, Head of Specialist Services said: "This would normally take months and involve very many individual closures of the line.

"This is a very inefficient way of working, mainly because much of the time is spent preparing and lifting the closure each time the railway is shut. A relatively short period is spent on actual construction work."

It was therefore decided to use new technology to "launch" the bridges into place - the first time this has been tried on such a large scale in the UK.

Pioneering Technology Used For Construction

Each 5,500 tonne bridge was constructed adjacent to the railway line. Hi-tech Teflon skid tracks, lubricated with a little household washing-up liquid were then used to literally slide the enormous structures into place using massive hydraulic jacks.

Mike said: "The operation was complex and painstaking but was a huge success. Because construction of the bridges was uninterrupted they were completed much more quickly. There was also a minimum of disruption caused to the railway line. Doing it this was a calculated risk but paid off enormously."

The operation to build and launch the bridges has since received a prestigious Construction Award from the Institute of Civil Engineers (ICE).

ICE President Quentin Leiper said the judges had agreed that the operation was such an exciting engineering success that it "makes the hairs on the back of your neck stand on end." 

Sustainability

Over 95% of the bypass has been built using materials recycled or excavated close to the site. 

Bypass building materials from power station waste

It was quickly realised that the proximity to Rugeley's enormous power station represented a major opportunity.

One of the by-products that the power station produces is large quantities of "fly ash".

New technology has been used to incorporate this ash into a useful road building material. Hundreds of tons of ash have been used in the making of the bypass.

"We saw it as an innovative solution for the use of recycled materials because it was something we had on our doorstep from the power station," said John.

"Power station waste has been incorporated into the embankments, road pavements and the concrete for the bridges." 

Other recycled material includes earth removed from the bypass "flood plain compensation area".

John explained: "This has basically involved digging a large trench near to the bypass. By building on a flood plain we have reduced the ability of the land to absorb flood water from the River Trent. The trench compensates for this and minimises the impact of the road on the natural capacity of the flood plain to cope with flood water."

Normally such compensation schemes involve massive amounts of material being removed from the site, involving hundreds of journeys by heavy trucks. At Rugeley however all the excavated material has been moved just a short distance and incorporated into the road embankments.

Green boulders

Much of the engineering effort has revolved around the fact that Rugeley Bypass stands of the flood plain of the River Trent.

There have been two major considerations. Firstly, it has been necessary to make sure flooding isn't displaced by the construction of the bypass resulting in flooding to nearby homes and businesses which did not previously suffer. Secondly it is necessary to ensure that the new road isn't itself damaged by floods.

Efforts to Make Area Look as Natural as Possible

The answer has been to raise the road on an embankment protected by flood arches, allowing flood water to pass underneath the road. These have already proved to be effective during this summer's deluges. They have the added bonus of being aesthetically pleasing and are an elegant feature of sections of road.

However there were other considerations. Because flood water may frequently lap against the embankments it is necessary to protect them from damage.

The traditional way of doing this is to pile massive boulders around the base of the structure. But this is both expensive and has an environmental impact, because boulders weighing hundreds of tons have to be quarried and then transported to the site.

The answer has been the use of cement stabilised boulders - large blocks of concrete that are constructed in-situ.

"The only big drawback with concrete stabilised boulders is that they are ugly," said Mike.

"So we have used new technology that covers the boulders with a specially developed plastic fabric. The fabric can then be seeded with grass and the boulders then take on a natural look and become indistinguishable from a grassy bank.

"From an engineering viewpoint it is a very pleasing solution because it does the job, it is considerably cheaper and it looks good."

Construction Elements Brought Together From Factory

A road built in a factory

The traditional way of building structures such as the flood arches of Rugeley Bypass is to make then on site by pouring concrete into wooden moulds.

The main drawback is that the work is subject to weather, which can casue considerable delays. So Rugeley Bypass has used factory built units wherever possible.

Mike said: "Construction is in a much more controlled environment. The weather isn't a factor, which can save considerable time, and quality control is really simplified.

"The flood arches for Rugeley were actually made in Northern Ireland. They were transported to the site and simply lowered into place. Again this is an engineering solution that saves time and cuts costs by a considerable amount over traditional methods."

Last Modified: 23/11/2007 11:29:56
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