INNOVATION July-August 2014

The Faith Irrigation System The Faith Irrigation System is a charitable initiative of Ratanak International. The dam and dike system in the Pouk District of Siem Reap, Cambodia, built in 2013 with the help of local villagers, is designed to channel floodwaters caused by extreme weather while retaining enough water for agricultural use. Treacherous floods, have caused uncertainty in the livelihood of 20,000 villagers dependent on crop production. Just-in-time completion in September 2013 saw subsequent extreme flooding affect much of the country’s rice production, while the Pouk District was saved from damage and harm. The cooperative development of the Faith Irrigation System has brought pride of ownership and a greater sense of community and responsibility to the people of this region. A new bridge built alongside the dam has improved an important arterial road for the community. APEGBC professionals involved: Jack Gin, P.Eng.

Push Boats and Barges for the Rio Parana /Rio Paraguay Waterway This river transportation project will ultimately see a fleet of eight push boats and 144 hopper barges moving iron ore from Vale’s Corumba mine in SW Brasil, 2,500 km to tidewater near Buenos Aires. This fleet has all been designed by Robert Allan of Vancouver, building on their experience designing extreme shallow draft vessels for the Canadian northland.

The 46.5-m push boats, built by Uzmar of Turkey, are propelled by a state-of-the-art, diesel-electric propulsion system with three main diesel generator sets each providing 1,710 eKW to a 1,600 KW motor, which in turn drives a Schottel SRP 1215 Z-drive unit. The barges were built by ZPMC of China and are being delivered in batches of 32 by submersible transport. Project team: James McCarthy, P.Eng.; Erik Johnston, P.Eng.; Lawren Best.

Rescuing Bertha The world’s largest tunnel boring machine, Bertha, is incapacitated due to mechanical failure. Bertha’s stoppage places her 25 m below the surface between the aged Alaskan Way Viaduct and the Seattle Seawall. Accessing Bertha with a vertical shaft provides the best approach to access all facets needed for repairs. Due to the limited area above the tunnel alignment and physical constraints bound by existing infrastructure, the dimensions of the otherwise symmetrical shaft are heavily impacted, thereby requiring special attention to design and layout. Consequently, the shaft design requires a combination of 3 m, 2.5 m, 2.2 m, 1.5 m and 1 m diametre unreinforced drilled secant piles coupled with various jet grouting techniques and dewatering. The shaft will allow the full removal of Bertha’s cutter face and her inner workings to facilitate a complete repair. Drilling contractor: Malcolm Drilling Company. Engineer: Brierley Associates. General contractor: STP JV. Owner: Washington State Department of Transportation.

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