Search Results: 'Robbins'

Tunnelling's flexible friend
01 December, 1999
Sometimes viewed as a poor relation to fully mechanised excavation, drill+blast still holds an important place in the tunneller's armoury. Technical Journalist Maurice Jones reports that an increasing level of sophistication in drilling and explosives use ensures a fair share of work, sometimes when other methods fail.

Breakthrough on troubled SSDS
01 December, 1999

Underground expertise at Hagerbach
01 December, 1999

MetroWest finale
01 November, 1999

LA Metro: North Hollywood Project
15 October, 1999
On June 17 at a meeting of the BTS held in the Institution of Civil Engineers in London, Alastair R Biggart , Vice President, Hatch Mott MacDonald, presented a paper on this project, which, after many difficulties, is due to open in May 2000.

TARP: last leg begins
14 October, 1999

Brisbane sewers
14 October, 1999

TBM performance estimation in rock using QTBM
16 September, 1999
Nick Barton, Technical Adviser, NGI, Norway, Visiting Professor at the University of São Paulo, Brazil, has developed a new method for predicting penetration rate (PR) and advance rate (AR) for TBM tunnelling. This method is based on an expanded Q-system of rock mass classification and average cutter force in relation to the appropriate rock mass strength. Orientation of fabric or joint structure is accounted for, together with the compressive or point load (tensile) strength of the rock. The abrasive or non-abrasive nature of the rock is incorporated via the University of Trondheim cutter life index (CLI). Rock stress level is also considered. The new parameter QTBM can be estimated during feasibility studies, and can also be back calculated from TBM performance during tunnelling.

Run-of-the-river hydro for Peru
16 September, 1999