A comparison of rock mass disturbance in TBM and drill and blast drivages at the Donkin Mine, Nova Scotia

Autor: C. M. K. Yuen, J. L. Gilby, T. R. C. Aston
Rok vydání: 1988
Předmět:
Zdroj: International Journal of Mining and Geological Engineering. 6:147-162
ISSN: 1573-1529
0269-0136
DOI: 10.1007/bf00880804
Popis: The initial phase of the Donkin-Morien project involves the driving of two parallel tunnels through an interbedded sequence of coal measures strata to intersect the Harbour Seam which lies approximately 3.5 km offshore. The No. 2 tunnel was driven a total distance of 3579 m using a 7.6 m diameter full face shielded Lovat TBM and supported by steel ring beams. The No. 3 tunnel was initially driven a distance of 1027 m using conventional drill and blast methods (7.6 m wide by 5.3 m high with a uniradial arch and supported by rock bolts and shotcrete). The TBM was subsequently used to complete the drivage of the No. 3 tunnel to the Harbour Seam. Both the No. 2 and No. 3 tunnels followed a thick sandstone unit at a grade of −20% for the first 900 m. This provided an opportunity to compare the rock mass disturbance resulting from two different excavation methods. A programme of field and laboratory measurements was therefore undertaken, which included: the use of a borehole dilatometer to determinein situ rock modulus,in situ gas permeability testing, seismic reflection surveys on the tunnel walls, and the laboratory testing of core samples. The paper examines the four different techniques used and compares the results obtained.
Databáze: OpenAIRE
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