30 October 2010

Reports suggest that the Kolontar dam collapse was associated with foundation failure

Posted by Dave Petley

Image source: http://derstandard.at/1285200400578/Ansichtssache-Luftaufnahmen-des-Katastrophengebiets

Source: http://derstandard.at/1285200400578/Ansichtssache-Luftaufnahmen-des-Katastrophengebiets

Thanks to Peter Diehl for his continued hard work with this issue.

Regular readers will remember the Kolontar dam failure event in Hungary early last month (see image to the left).  Based on the images published of the event, I speculated a couple of days later here that the failure of the dam might be associated with problems with the foundations.

In the last week newspaper reports in Hungary have suggested that the investigation does indeed suggest that foundation failure may be the cause of the accident.  This article in particular addresses this issue directly.  It is in Hungarian, and my skills in that language are somewhat rusty, so I have had to rely upon the Google translation service.  My corrected version of the Google translation of the salient part of the article is that the dam was underlain by a slurry / grout wall intended to prevent seepage.  However, deformation and fracturing of the soil occurred over a 50 metre stretch, allowing the dam wall to move forwards and fail.

The article says that further investigations are needed, but this would seem like a logical interpretation based upon the evidence available from this distance.  It will be interesting to see the nature of the final report in due course, and we must of course be careful not to over-interpret until the final investigation is complete.