As Eurocode 7 becomes the latest standard to become compulsory on public infrastructure projects from 1 April, Bernadette Redfern finds out how prepared the industry is for its implementation.
On 31 March BSi, the body responsible for developing design and construction standards in the UK, will withdraw its support of the current British Standards for geotechnical design and switch its allegiance to what will become the UK’s new standard, Eurocode 7 (EC7).
“Eurocode 7 is broken into two parts: part one which deals with general geotechnical works, and then part two which deals with ground investigation and testing,” explains BSi committee manager for standards development Clare Price.
“Each has a national annex issued separately, which is produced by the UK code committee. The end result isn’t that different, it is just the method that has changed.”
It is here, in the detail of the new methodology, that a thorough understanding of the new system is required.
Designers, contractors, architects and manufacturers must familiarise themselves with the new approach to ensure that all parties are working with the same information.
That design loads, for example, are passed on to contractors in the correct format, with the appropriate information gathered from site investigations.
But just how prepared are all the parties for the implementation of the new codes?
The consensus is that the geotechnical industry could be better prepared, but things could be a lot worse. “Preparedness varies across the industry,” says Keller chief engineer Derek Egan.
“There is a feeling that many people don’t really know how it is all going to work in practice. For example, when are we going to get loads in eurocode format.”
Keller has been working hard to ensure its staff are ready for the move.
“Within Keller we have undertaken training and developed the tools to make sure that we can do our EC7 designs effectively. We are asking questions such as what is the impact on the pile length? And will we be affected commercially?”
In mid January the firm had an internal meeting to discuss parametric studies.
“We asked people across the company to do parallel EC7 designs, which we can compare ‘traditional’ design with those given by the Eurocode,” Egan says.
Eurocode committee representative and EC7 expert Andrew Bond, director of Geocentrix, says this is a wise move.
Bond has been delivering training programmes across the industry and says it is critical that firms give themselves adequate time to understand the extent to which the new standards will affect projects.
“Taking a one-day course on this will not tell you everything you need to know,” he warns. “It is so extensive that you need to invest significant time. You need to spend at least two or three days, spending time trying examples.”
Despite the looming deadline, Bond says that less training is being undertaken than he expected.
“Right now I would expect the training to be flat out, but there is a little thing called the recession. People need training as the deadline is April, but budgets are tighter than ever and it is just the wrong time to be shepherding this in.”
“Not everyone is 100% prepared; we are probably better prepared than most,” says Aarsleff Piling chief engineer Bob Handley. “Overall it took more than a year to go through the testing and third party accreditation process for registration.”
Aarsleff Piling’s manufacturing division, Centrum Pile, makes precast concrete piles that fully comply with the requirements of BS EN 12794:2005 and are designed in accordance with Eurocode 2, which covers structural concrete.
Centrum Pile was awarded a Certificate of Factory Production Control in March 2007 and Aarsleff got started early on understanding the requirements of EC7 in 2008.
A catalyst for that early start was the fact that its piles are used extensively in the wind turbine business, where European manufacturers were already using Eurocodes.
“We started off in the summer of 2005 applying global factors of safety in geotechnical pile design, which we knew would satisfy the turbine manufacturers,” explains Handley.
“We have gradually refined it to the point where we generally get loading information from the foundation designer in the same way that it should, later this year, come in from everyone else.”
The format of pile loading information is a potential sticking point when it comes to implementing EC7.
Contractors fear that some consultants may not be fully aware of how the codes impact on the design information that must be gathered and the format in which it must be shared under the new rules.
“The only real bottleneck in the design process that we can foresee is if consulting engineers don’t get used to providing pile loads in the right format, in other words declare whether or not they are factored, which load combination they apply to and whether they are characteristic or whether they are representative,” says Handley.
But consultants say they are prepared for the changes.
“Major consultants are ready and there has been a lot of training over the last 18 months and most have done some design using EC7 already,” says another EC7 committee member, Arup director Brian Simpson, although he concedes that training could be an issue for smaller consultants.
Other consultants say the situation varies between firms.
“Some are very well prepared, particularly those that have been working on the Eurocodes for many years. Others are clearly working hard to be ready,” says Steve Denton, director of bridge and structural engineering at Parsons Brinckerhoff (PB).
Among other things Denton is a member of BSi committees B525 and B526a, and has been heavily involved in UK implementation, advising many national clients and serving on key committees and steering groups.
“At PB we undertook Eurocode awareness training for our staff back in 2006, and last year provided detailed three-day training courses,” he says. “In the future we will be focusing on developing further specialist training modules.”
Bond believes that there could be disputes over the finer details in the new codes.
“Everyone is aware that major changes are coming but are not all up to speed with the detail. There are lots of documents that people are not aware of. Eurocodes depend on other documents, such as execution standards. Consultants are not fully aware of these and are not specifying them, so by April by default a contractor will use these, and that could lead to a dispute on the contract.”
An example of a potential disagreement is tolerance for pile verticality.
There could be an issue if the designer is not aware of what values are given in the execution standard and they are tighter than specified.
“It is all about the detail; some things have changed, some are the same, but you have to look at specifics. It is a new set of documents and the main thing is that everyone works together,” says Bond.
Adequate training will make a big difference, but there is a definite feeling in the industry that the proof of success will be in the execution of the projects.
Doubts may persists over how prepared various parties are until projects begin to use the standards effectively.
There is no doubt however that the new standards must be used.
“If engineers continue to use the withdrawn standards there are issues of liability,” says BSi head of construction Jonathan Griffin.
“If any legal proceedings related to structural design arise then what happens in a court in deciding whether the designer or engineers are being negligent will refer to the state of the art standards, and these will be the Eurocodes,”
The good news is that experts such as Bond say that UK engineering firms compare favourably to their European counterparts, although some states are further ahead.
“We are not as on top of this as the Germans, but we will have all the documents ready,” says Bond.
A major change in the standards is that Eurocodes demand that users cross reference between codes.
“We are moving from a single code of practice to an integrated set of EU documents,” says BSi committee manager for standards development Clare Price.
“The Eurocodes all fit together and will be used as a whole. They cross-reference quite heavily.”
A full list of these documents can be viewed at www.eurocodes.co.uk