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Back Analysis of Open-Pit Slope Failure, USA.
Geotechnical review and back analysis of two major 350 foot high pit wall failures, each comprising approximately 12 million tonnes of failed material. Created a
geological/geotechnical model based on pit mapping, borehole data, and laboratory testing of the weak sedimentary sequence.
Busted Butte Unsaturated Zone test facility, Yucca Mountain Project, Nevada, USA.
Review and analysis of SI data and fild mapping data for the design of a tunnel
portal in massive weak tuffs. Rockfall hazard assessment was performed on the slope above the portal, followed by rock cut design and support using 2.4m long rockbolts and shotcrete. A 2.0m high catch fence was also
designed to protect the portal area and access road from rockfalls.State Route 91, USA
Preliminary route selection and outline design for a 4Km section of re-aligned highway due to severe mining
subsidence. Proposed road was at maximum grade for much of its length and involved four rock cuttings up to 80m high. Napton Industrial Estate, Warwickshire
Site investigation and field mapping;
slope stability analysis including back-analysis of periglacial slope failures in Lias clay, Design of landslip stabilisation scheme comprising drainage measures to improve slope stability; and retaining structures. Preparation of
final slope grading plans. Preparation of tender documents, including Specification, Bill of Quantities; and CDM submissions.
A55 Pen-y-Clip Tunnel Rockfall Hazard Assessment, Gwynedd
Supervision of oblique aerial
survey of mountain slopes. Field investigations and archive studies to assess rockfall hazard potential. Production of a rockfall hazard map to identify areas requiring specialist treatment. Supervision of rockfall
protection and stabilisation works including over 3 kilometres of rocktrap fencing and barriers, scaling, dentition, and rockbolt installation on the mountainside utilizing roped access. Preparation of maintenance
manuals for the rock fall protection works and retaining walls, incorporating Health and Safety regulations with respect to roped access.
Foidel Creek Mine Rockfall Hazard Mitigation, Colorado
Assessment and mitigation of rockfall hazards associated with
longwall mining below high sandstone cliffs, adjacent to a public highway. Project involved the use of field-calibrated rockfall simulation models and the development of a probabilistic rockfall hazard map. This
map provided the basis for siting catch berms and ditches, designed using the simulation program, which have subsequently proved successful in arresting blocks with volumes in the region of 350m3. For Twenty Mile Coal Co.
Removal of Unstable Rock by Blasting, Llanfairfechan, Gwynedd
Input to design and siting of sacrificial rockfall fences and gabion walls prior to removal of loose rock, from cliffs above Llanfairfechan town, by
blasting. Calculation of air blast relative to charge weight. Review and back analysis of video footage of fence performance and ultimate failure.
Interstate Highway 287, New Jersey, USA
Probabilistic assessment of rockfall hazards for road cuttings including development of a stochastic rockfall simulation and risk-analysis computer program.
Mount St. Helens National Volcanic Monument, Washington, USA
Geotechnical investigations, slope stability analysis and rock-cut design. Assessment of rockfall hazards, dimensioning of rock-traps and benches for State Route
504 (Spirit Lake Memorial Highway) - a new route to replace the road destroyed during the 1980 eruption of Mt. St. Helens. .
Post Pit and Betze Pit, Carlin, Nevada, USA
Monitoring and remediation of active
slope failures in a major open-pit gold mine. Including supervision of geotechnical data collection and data-base preparation; probabilistic slope stability analysis; review of long-term development plans; assessment of
rockfall hazards above permanent haul roads and capital plant.
Pinto Valley Mine, Arizona, USA
Blast monitoring and highwall stability analysis for an open pit copper mine, including rockfall hazard
assessment and proposals for risk reduction.
Denali Mine, Alaska, USA
Instrumentation and monitoring of an active slope failure, and successful prediction of a second major failure in a critical section of an
open-pit mine highwall. |
