6 October 2010
As predicted, a number of interesting images are now available of the site of the breach that caused the Ajkai Timfoldgyar tailings debris flow in Hungary on Monday. Thanks again to Peter Diehl for his tireless work in seeking out and highlighting the best images. The best slide show, surely destined to become an invaluable teaching aid, is available at this link:
In terms of the failure that caused this dreadful event, the best images are these two below. Take a little time to appreciate the scale of this – the first image has some machines in the foreground that provide perspective. The first image shows the breach itself:
The really revealing image is this one – the breach is to the right of the image. It suggests that this block had moved off its foundation and that the section close to the reach had moved forward. Note the material that has come through the resultant crack:
The fact that the final failure occurred in a right angled bend in the dam wall is very interesting, as this is a point of stress concentration. If I were the team investigating this failure I’d be very interested to see the calculations of uplift force on the base of the dam.