- Compliance and On-Call Geotechnical Engineering services/Technical Reviewer to Alameda County, California for SMARA (Surface Mining and Reclamation Act, State of California California). Also Technical Review for Santa Clara County with review of the expansion plans of the Lehigh Cement Permanente Quarry, Sunnyvale, California.
- Technical Reviewer, Geological and Hydrogeological Investigations for Granite Rock aggregate quarry located in a fault-sheared rock mass in the major San Andreas fault zone, at Aromas, Northern California. Reviewed preliminary concepts deepening the 100 year-old pit, which resulted in changes in the geological model of the rock mass. Performed innovative remote mapping of high pit walls using land-based photogrammetric techniques. The results of this study permitted an evaluation of the highly complex, faulted rock mass, composed of a mixture of weak sheared rock and competent blocks of rock.
Open Pit Mines/Quarries: Characterizations/Failures
- Performed a reconnaissance study of the failing high wall in complexly sheared Franciscan Complex rock at the Homestake McLaughlin gold mine in Lake County, California. The pit was nearing the end of its life and the high wall started to fail, threatening a water treatment facility near the crest. The client wanted to extract a high-grade ore zone at the base of the high wall, but to have done so would have increased the possibility of a catastrophic failure of the wall.
- Investigated the geological engineering and geotechnical engineering causes of a major landslide that threatened the tailings dam at the Golden Cross gold mine near Waihi, North Island of New Zealand. Testified at deposition for plaintiff; case settled prior to trial.
- At the open pit Syncrude oil sands mine near Fort McMurray, Alberta, evaluated the geotechnical suitability of fluvial and glacial overburden soils and oil sands for constructing for stable working surfaces for draglines, tar sand stockpiles, bucket wheel excavators and conveyor systems. Developed engineering geology maps of overburden soils and simplified maps for earthwork contractors showing usability characteristics of overburden soil.
- Consulted on overall geologic hazards associated with ongoing and planned pit expansions at the Lihir gold mine, Lihir Is., Papua New Guinea. One of the world’s most unusual gold mining operations, the mine is located within a volcanic caldera, with active geothermal conditions. Consulted on an unexpected failures in very weak, severely hydrothermally-altered tropical residual soils in chaotic geology. The failure had a significant impact on the Risk Management of future mine expansions. Based on my recommendations that further work be performed around the pit, the Board of Directors authorized a geological engineering review. Because of the dense jungle cover, the mine operator had a poor understanding of the geological and geotechnical conditions within the areas of future expansions. Survey information was also very sketchy. Accordingly , an airborne LiDAR survey was flown to generate detailed topography, which allowed a Terrain Hazard Assessment. In addition, consulted on use of GPS-based systems for monitoring mine wall and ore stockpile stability.
- At the world class Ok Tedi mine, was Field Project Manager and principal geo-professional of a 70-man crew providing comprehensive geotechnical services for the design-build contractor, Bechtel/Morrison-Knudsen JV. Project was the largest geotechnical services project in Australasia up to that time. Provided comprehensive geological and geotechnical data necessary for design and construction of the Ok Tedi mine and associated infrastructure.
- Performed geotechnical investigations and preliminary geotechnical designs for tailings dam additions at Sullivan Mine, (Kimberley, BC); Hecla Star Mine (Wallace, Idaho); and Hecla Lucky Friday Mine (Mullins, Idaho); investigated suitable borrow sites and monitored the construction of earth fill tailings dams for Hecla Star Mine and Hecla Lucky Friday Mine.
- Consulted for the Owner of an old quarry leased to Dutra Materials at Richmond, California. The pit has a very steep 350-foot slope within Franciscan Complex rocks. The project required a cooperative collaboration with other Consultants. Initially interpreted as coherent and stratified, the rockmass actually contained large, intact rock masses within extensively sheared and melange zones. Characterized the chaotic rock mass, investigated rock mass integrity, and evaluated static and seismic slope stability of the chaotic shear zones. Performed a detailed evaluation of geological and geotechnical conditions, and rockfall hazards. Presented findings at several Public Meetings of the California State Mining and Geology Board (SMGB).
- For Confidential Insurance projects, investigated the causes of slope instability and the effects of flood-related damage to operations at gravel pits on the Russian River, Sonoma County; on the Tuolumne River, near Modesto, California; and on the Truckee River, at Truckee, California. Investigated slope stability of failed slopes and discriminated those slopes that failed due to effects of rapid drawdown (following cessation of flooding and lowering of water levels) from slopes that failed for other reasons. Testified at deposition for one case, which was settled prior to trial.
- Investigated claims related to design deficiencies for the long conveyor system used to transport fill from remote borrow pits to the San Roque dam, a high multi-use earth fill dam in Philippines. Was the sole Technical Expert to testify at Arbitration Hearing; case was mutually withdrawn.
- Ground geophysics operator/data recovery and plotting for EM, Turam, VLF, Magnetometer and Induced Polarization surveys in Ontario, Manitoba, Saskatchewan and British Columbia (Canada).
- Geological prospector in massive sulphide prospects (Stikine River area, BC); Mississippi Valley-type Pb-Zn prospects in carbonates (Selkirk Range and Ogilvie Range, Yukon); and porphyry copper (Vancouver Island, BC). Also experienced as surface blaster, claim-staker, and line-cutter. Experienced in sampling stream sediments and soils for geochemistry analysis; backpack drilling; and rock-chip sampling.
- Helicopter and fixed wing airborne geophysics: flight path navigation /air photo interpretation for flight path recovery; data recovery/plotting/contouring for EM, Magnetometer and Radiometrics surveys in Ontario, Manitoba, Saskatchewan, Labrador and Northwest Territories (Canada).