About Eurocode 5 - Timber
KR Keerthi Ranasinghe
KR I’m Keerthi Ranasinghe and I work for a company called Trada technology which is part of the bigger Trada group and I work there as a senior structural engineer. My role is, at the moment, helping industry with converting to Eurocode five most importantly but at the same time I help the companies to do their structural engineering calculations and get their products certified to European standards.
IV Can you tell us a little bit about your involvement with the Eurocodes?
KR About two years ago I started delivering Eurocode five lectures together with the Institute of Structural Engineers. My idea was structural engineers at that time were not fully aware of the implications of Eurocode Five so I went in with an engineers perspective trying to understand how the calculations should be done and I had some backing up sample calculations to help them with. That was about the time when they wanted to do their own calculations, so I timed it to match with that. My involvement so far with the Eurocode Five is basically teaching Eurocode Five; in fact I’m a visiting lecturer at Surrey University as well and I do a lot of training courses, seminars, workshops with the help of Trada and Institute of Structural Engineers as well.
IV Are you involved with one of the BSI committees at all as well?
KR Not directly but as you know Trada is contributing a lot to Eurocode Five. We have two members representing Trada and I do most of the technical work behind the scenes to help them to come to the Eurocode committees.
IV Can you tell us a little bit about the challenges that people are facing with the change over to Eurocodes?
KR I don’t particularly like the word challenge, it’s an opportunity, but I understand what you ask by challenges. There are many challenges, to start with Eurocode Five is not a standard that we used to look at, it’s more like a technical document or a research document I would say, it doesn’t contain any of the material strength properties for example, so the challenges that the end user of Eurocode Five, the structural engineer has to face with is finding the relevant values and do all the number crunching. There are a lot of equations and expressions given in Eurocode Five unlike the previous one, the 5268, which was basically tabulated and table orientated approach. Eurocode Five, the challenges are finding the correct values to use with Eurocode Five and then doing the correct number crunching required.
IV What do you think companies can do to overcome these challenges and what are you doing as a company?
KR I think it’s making your employees aware of what the changes are, so it depends on what sort of a company you are. If you’re a structural engineering consultancy for example you have to get your engineers trained in Eurocode Five, this is my personal experience, you can not just go in and open a Eurocode five and start doing calculations. BS5268 was entirely different, even if you’re doing it for the first time, within a couple of hours you could grasp the whole thing and then do your designs correct but this Eurocode Five is so involved you have to get your engineers trained. On the other side if you are a supplier or a manufacturer then you need to know all the intricacies of Eurocode Five and all the accompanying codes which we call harmonised standards. If you are keen to get your product into the market with proper certification then you need to read a lot about these standards and then do what is required to get your products certified. So two things really, engineers they need to train themselves, product manufacturers and suppliers they need to read a lot and understand what it is all about.
IV How do you think Eurocode Five differs from the actual British Standards they’re going to replace?
KR As I said previously Eurocode Five is more like a technical document where the principles and the fundamentals are given but hardly any help is given for you to do your calculation from a to z. The previous one was more like a technical manual, if I may use the word, with little experience you can open up a former British Standard and do you designs. On the other hand Eurocode Five requires the support of other literature, for example you cannot do a design without the property values then where do you get these values from? 5268 contained these values within the code itself so it’s just one document on your desk you can do your designs, Eurocode Five is not, so that’s a bigger difficulty.
IV You’d think that the training is essential when using Eurocode Five?
KR Training is essential and I think so far only the bigger companies have thought of doing proper training. I’ve been doing a lot of training for about two years now, some of the individuals like small practitioners they complain that the amount of information that they have absorbed within a short period of time is so much that it’s not going to happen. My view is quite different, I’m a structural engineer, if I want to survive in this industry for the future then I have to get on with it. So Eurocode Five is no exception, you either learn it or, I don’t know, you have to be left behind.
IV Can you tell us a little bit more about Eurocode Five, all the various parts and how they fit together?
KR Eurocode Five, like all the other Eurocodes, is looking at the particular matter they call timber and it is made up of three parts. Part one is about the requirements for general construction, part two is about fire requirements and the part two proper is about bridge engineering and it is supported by three national annexes as well for each one of these parts. It’s also supported by various other standards like what I was mentioning previously, the harmonised standards for products. If you are designing in soft wood timbers with rectangular cross sections there is a harmonised product standard for that and if you are thinking of doing designs in glulam then it’s supported by another harmonised standard. All in all you might be looking at something like 50 standards all together before you can do any meaningful design.
IV How did you find your personal experience of getting used to Eurocode Five?
KR I have to be honest here but at the same time I cannot say that it was a difficult thing. It was difficult at the beginning, to read all what is required and read all the supporting documents as well. One of the difficulties I found was finding all the supporting standards, so once you have all these things through BSI or by subscribing to any subscription services you can get hold of all these standards required. Once you get the initial feel for it, it’s not difficult at all, it’s just that for each design that you have to do you have to do loads of calculations, that’s where the difficulty is. I cannot insult my profession by saying it’s a difficult one, it’s not difficult but it’s time taking and time consuming.
IV Once you got used to using the Eurocodes do you find them quite beneficial in comparison to the British Standards?
KR Yes in a way because when I started the first thing that I did was, every part that I understood I put them into a computer package so you could reuse your calculations, so I that sense the formulae given in Eurocode five is most helpful compared to BS5268 where there were a lot of tables without much background about the tables. Once you use one calculation once you can repeat it quite easily with the use of computer, so that’s one of the key things about Eurocode Five.
IV Do you have any words of advice for people in the industry that are quite worried about using the Eurocodes?
KR I think my key advice is there’s plenty of information around; you can search online, you can come to Eurocodes website. There is the Institute of Structural Engineers, BSI and Institute of Civil Engineers collaborative effort called Eurocodes Website, there’s lots of information there about your particular field of interest, so if you are interested in scale there’s lots of information there.
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