DEAN BROX CONSULTING
UNDERGROUND DESIGN AND CONSTRUCTION
Dean Brox Consulting provides underground design and construction services for Civil, Hydropower, Mining, and Other projects. This page presents a brief description of some current and recently completed underground design and construction projects. Please refer to the additional menus for Civil, Hydropower, Mining, and Oil and Gas projects.
LESOTHO HIGHLANDS WATER PROJECT, PHASE 2, LESOTHO
Panel of Experts for 38 km, 5 m diameter water transfer tunnel and 164 m high concrete face rockfill dam (CFRD) in non-durable basalt bedrock.
Phase 1A of the project water designed and constructed in the late 1980's and early 1990's and comprised the 180 double curvature arch Katse Dam, the 45 km transfer tunnel and the 37 km delivery tunnel. Phase 1B of the project comprised the 32 km Mohale transfer tunnel and 6 km Matsoku transfer tunnel that was constructed in the early 2000's.
NIDO DE AGUILAS HYDROPOWER PROJECT, CHILE
Technical advisor for underground works comprising 10 km headrace tunnel and powerhouse cavern.
Pacific Hydro Chile is developing the 110 MW Nido de Aguilas hydropower project sited in the upper reaches of the Cachapoal River located 100 km south of Santiago. The project includes a 10 km headrace tunnel, underground powerhouse cavern, and intake structure at the Pejerreyes Lagoon. Services include technical review and evaluation of project design layout, geotechnical investigations including exploration gallery and/or long horizontal drillholes with in situ testing, detailed engineering, project risks and contract strategy and documentation.
LOS CONDORES HYDROPOWER PROJECT, CHILE
Technical advisory services during construction of a 12 km, 4.5 m diameter TBM excavated headrace tunnel through challenging geological conditions.
Endesa/ENEL Chile is developing this 150 MW hydropower project comprising a 12 km, 4.5 m diameter hydropower tunnel along with an underground powerhouse cavern and pressure shaft.
Services include an independent risk assessment for the use of the proposed double shield TBM through major geological fault zones, TBM factory inspection of TBM assembly and TBM design review, technical discussions with tunnel contractor regarding risk reduction methods, and site visit during early construction to evaluate encountered geological conditions to date. Ongoing services include risk evaluations and mitigation strategies during construction.
ALTO MAIPO HYDROPOWER PROJECT, CHILE
In situ stress testing and specialist advisory services for underground works comprising 70 km of tunnels and 2 powerhouse caverns.
AES Chile is developing this 531 MW hydropower project comprising 70 km of tunnels including three long and deep tunnels of lengths 13, 14, and 15 km. Services include in situ stress testing using CSIRO overcoring at multiple locations during the early stages of excavation of the access tunnels into the underground powerhouse caverns, specialist advisory services relating to the evaluation of overstressing along the long deep tunnels.
BIG SILVER CREEK HYDROPOWER PROJECT, CANADA
Design and construction of 1.8 km, 6 m wide drill and blast tunnel and large portals.
The Innergex Renewable Energy is developing this hydropower project comprising a 1.8 km, 6 m wide by 5.5 m high hydropower tunnel for power generation of 40 MW under an operating head of 30 m. Services include final design of the intake and outlet portals, the main power tunnel, concrete plug and rock trap components, length of steel lining, and field review services during construction. All services performed under a design-build project delivery in conjunction with the tunnel constructor joint venture CRT-EBC.
LOS ARANDANOS HYDROPOWER PROJECT, CHILE
Geotechnical investigations for 14 kms of tunnels.
Technical advisory services were provided to Pacific Hydro Chile for a major geotechnical investigation program for the proposed Los Arandanos Hydropower Project located south of Santiago. This new project is to replace the existing Coya 1 operating Plant and includes 14 kms of tunnels, 2 surface intakes along the Pangal and Cachapoal Rivers, siphon, control pond, and a surface powerhouse with an installed capcity of 76 MW. The geotechnical program comprised the drilling of 33 boreholes (3360 m) using diamond and sonic drilling methods, in situ permeability, hydro-jacking and hydro-fracturing testing, standard and specialized laboratory rock testing, and test pits.
RED LAKE GOLD MINE HIGH SPEED TRAM TUNNEL, CANADA
Extreme convergence of weak rock at 5000 feet below surface.
Goldcorp Red Lake Gold Mine is developing the 6 km High Speed Tram (HST) Tunnel to provide access to a new potential mining area underground. The HST was excavated to a width of 14 ft (4.3 m) and a height of 16 feet (4.9 m) through 2000 feet (610 m) of the well recognized talc-schist rock type known throughout northern Ontario as a problematic rock unit for underground mining. Standard rock support was installed during the original excavation that resulted in extreme convergence of the tunnel walls extending to as much as 2 feet for a strain level of about 30%. Extensive closure and mutliple point borehole extensometer instrumentation was installed and monitored to evaluate ongoing deformation. Additional tunnel support comprising higher capacity and longer rock reinforcement was introduced concurrently with excavation to reduce movement. Trials of different forms of rock reinforcement were introduced and evaluated to select the permanent support for the HST for rail track installation and future traming operations.