Yet again we see a rush to condemn the New Austrian Tunnelling Method (NATM) out of hand for a tunnel collapse (NCE last week), the cause of which I expect will be found to have no bearing on the method whatsoever.
NATM is no more controversial than any other tunnelling method and suffers no greater mishaps than traditional or purely mechanical methods - and possibly less than many. This is perfectly demonstrated by the article on the same page referring to the Singapore cut and cover tunnel collapse, which was far worse than the Barcelona incident.
NATM has been used worldwide since the 1970s with innumerable successful projects, both technically and commercially, to its credit.
However, just because a tunnelling method uses sprayed concrete does not mean it is NATM. In this country we have recognised that these techniques form only part of an overall methodology referred to as the sprayed concrete lining or SCL method.
So what is in a name?
Frankly, nothing. Tunnelling is tunnelling by whatever method is most appropriate for the situation. Accidents occur for only a very limited number of reasons: namely, bad or inappropriate design, poor ground investigation or understanding of the ground conditions, and poor workmanship.
Dave Hindle (M), dvdhindle@aol. com