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The use of transmissivity data from the probe holes for predicting tunnel grouting: Analyses of data from the access tunnel to the Äspö hard rock laboratory

✍ Scribed by Å. Fransson; G. Gustafson


Publisher
Elsevier Science
Year
2000
Tongue
English
Weight
535 KB
Volume
15
Category
Article
ISSN
0886-7798

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✦ Synopsis


Results from hydraulic tests in probe boreholes in the access tunnel to the iispd Hard Rock Laboratory, Sweden, were compared to the amount ofperformed pre-grouting of the tunnel made in order to reduce water inflow. It was found that the probe holes identified the major hydraulic conductors well. Also, parts of the tunnel with very tight rock could be predicted. In the intermediate range, the precision of the grouting predictions can be improved with a probe hole pattern that is better djusted to the geometry of the conductive fractures. Data for this can be obtained by mapping of orientation and trace lengths of the water bearing fractures.