AGS Comment on Geotechnical Sampling to Eurocode 7
In the September 2011 issue of the AGS Newsletter “ Advice to AGS Members on Geotechnical Sampling in Relation to Eurocodes” makes no reference to the paper “Ground Investigation and Eurocode 7: A Scottish Perspective” (Ground Engineering Magazine, July 2011, pg26-31) relating to the difficulty in obtaining Class I samples from stony glacial till. I presume that the guidance note was issued without the knowledge of this paper. I would seek your comments on the above given the position statement now issued to members of the AGS.
As regards section 4.0 of the guidance note I would draw your attention to the contents of the paper which essentially demonstrates that some amendments to BS EN ISO 22745-1 are necessary and best achieved through open dialogue as opposed to proving the point in any court action. Dr J Taylor, Geotechnical Engineer.
The advice note that appeared in the September edition of the AGS newsletter was intended to convey the fact that both EC7 and its supporting documents could, in relation to geotechnical sampling, be used in the UK by the geotechnical industry. In preparing the advice note, the authors deliberately referenced the available published guidance on EC7 so that readers had additional material to which to refer.
Ever since the introduction of EC7, and more particularly BS EN ISO 2245-1 (the latter which was published in 2006), certain proactive elements of the UK geotechnical community have recognised the need to integrate the ‘new’ standards into the site investigation industry. That is not to say that some errors and contradictions haven’t been identified in the standards. Indeed these have been well documented and are available elsewhere for reference.
The standards are, however here and for the time being the UK geotechnical industry needs to make use of them. EC7 and BS EN ISO 22475-1 provide plenty of scope for the site investigation designer to choose sampling and / or in situ testing techniques appropriate to the diverse range of material types that occur in the UK. EC7 even allows the geotechnical specialist to use ‘local knowledge’ as a ‘trump card’ if they believe that this is more reliable than trying to obtain samples in particular classes.
It has long been recognised that there are both soil and rock types within the UK that present a challenge with regard to sampling and in situ testing. These material types have always been present and obviously predate the introduction of Eurocodes. Such challenging materials have always required the site investigation designer to think about the most appropriate methods of obtaining deign parameters; but as Baldwin and Gosling pointed out in their article in Ground Engineering in 2009, this was often not done. With the advent of Eurocodes the designer is forced to think about how best to obtain design parameters and record the rationale for the method(s) adopted. This should be seen as a step in the right direction as far as quality is concerned.
For those in the industry who believe that changes need to be made to the Eurocode documents used in the UK, there are mechanisms for their voices to be heard. Constructive comments can be directed to the appropriate UK standards committee who are tasked with relaying comments made by industry in the UK to the European central committee tasked with producing the first revision / update of EC7 and 22475-1 etc.
Professionals working in the UK geotechnical industry can endlessly debate the merits of Eurocodes for use in the UK. This, however, will not change the content of EC7 et al. The most effective way to get documents improved is to collate constructive comments with the UK standards committee and then let them represent the UK. A collective voice will carry far more weight than individual comments that are lost in the ‘ether’ of local debate.
The AGS is willing to act as a recipient for comments that members may wish to make in relation to EC7 and other supporting documents. Such comments can be as general or specific as members wish, but must be constructive since the basis for discussion is the fact that these standards are in force and can only be modified with good reason.
C Danilewicz- Halcrow and M Baldwin- Soil Engineering