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Published in: International
Journal of Soil Mechanics and Mining Sciences, 39 (2002) 771-788
Abstract
Three tunnels for hydraulic purpose were excavated by tunnel boring
machines in mostly hard metamorphic rocks in Northern Italy. A total
of 14 km of tunnel was surveyed almost continually, yielding over 700
sets of data featuring rock mass characteristics and TBM performance.
The empirical relations between rock mass rating and penetration rate
clearly show that TBM performance reaches a maximum in the RMR range
40 to 70 while slower penetration is experienced in both too bad and
too good rock masses. However, as different rocks gives different
penetrations for the same RMR, the use of Bieniawski's classification
for predictive purpose is only possible provided one uses a normalised
RMR index with reference to the basic factors affecting TBM tunneling.
Comparison of actual penetrations with those predicted by the
Innaurato and Barton models shows poor agreement, thus highlighting
the difficulties involved in TBM performance prediction.
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the data files !
We are happy to place the data
set used in the paper at everyone's disposal, so to promote
refinements of existing predictive models and to facilitate the
comparison of our results with other experiences. Of course, let us
know if you intend using the data for publication in scientific papers.
TBM_Performance02.xls
(Microsoft Excel format)
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