Helping water flow in arid Great Plains
Helping to replenish drought-hit cities is the job of three Volvo excavators, digging deep to rebuild the underground infrastructure of the Great American Desert in North America.
Amarillo, Texas, sits in the crosshairs of America’ s routes 40 and 287, and is a waypoint between Albuquerque and Oklahoma City. The area is rich in cowboy culture and mementos of its Route 66 heyday, best symbolised by the Cadillac Ranch, located just west of the city.
But beyond the tourist attractions, the semi-desert region of the High Plains in which Amarillo is located is the sunbelt of the south. The average annual rainfall is less than 60cm and the heat is often upwards of 43 ° C. With several droughts in recent years, water is in short supply. Lake Meredith, one of the city’ s main water sources, is dwindling, placing greater demands on the Ogallala aquifer: the vast underground reservoir that supplies Amarillo’ s 190 000 residents.
As a conservation effort, the city recycles and sells back more than 18 billion litres of effluent each year to regional electric utilities as cooling water for generators. Recently, the Potter County Wellfield— the first major wellfield since 1956— was drilled, bringing water to Amarillo to help sustain residential and commercial growth.
On average, Amarillo Utility Contractors places more than 600 000m of water and sewer pipe each year.“ When I started the company, our projects were relatively small and shallow,” Taylor recalls.“ Over time, we’ ve taken on more challenging projects.”
To maintain high performance in the extreme environment, the Volvo EC350E features a hydraulically driven, electronically controlled cooling fan, designed to protect machine vitals.
With over 1 600km of wastewater lines and 200km of stormwater drainage snaking below the city, the company is hard at work to repair, replace, and rehabilitate the water and sewer lines— most of which date back to the 1950s.
To match the deep trenching and large pipe requirements of urban projects, Amarillo Utility Contractors decided that it needed to upgrade its fleet. After attending the 2015 Volvo Days customer event in Shippensburg, Pennsylvania, Taylor added three Volvo EC350E crawler excavators to his fleet of 13 machines. u
Precast system saves six months on reservoir build
A novel precast system has helped shave as much as eight months off a reservoir construction programme in Katlehong, Gauteng. The roof of the 30 mega-litre reservoir comprises more than 2 000m 2 of slabs, each up to 250mm deep, and is supported by 16 columns and 18 beams, weighing a total of 12.3t and 7.5t, respectively.
The system was designed, manufactured, and installed by Corestruc, complementing its already impressive portfolio of completed precast concrete structures, ranging from public sector infrastructure projects through to private property developments. On this project, Corestruc worked closely with civil engineering contractors, Civcon and QC4 Civils, as well as consulting engineer, TLS Engineers & Project Managers, to deliver the project on behalf of Ekurhuleni Metropolitan Municipality.
QC4 Civils’ contracts manager, Ettiene Coetzee, says that this is the largest reinforced post-tensioned ground reservoir to be built by the company, as well as the first such structure to feature a precast concrete roof. Coetzee is extremely impressed with the system and service he received from Corestruc, noting that the professional team had allowed for 26 weeks to build the structure; however, this period could easily have been halved using the system.
“ One of the biggest advantages is that it can be installed without the need to erect, dismantle, and remove tons of supporting scaffolding, while the precast system can be programmed concurrently with other activities and, therefore, does not restrict multiple activities on site,” he says.
Corestruc’ s involvement in the project started right from the outset in its design stages, when every aspect of the system was finalised right down to the type of connection that would be used to build the roof. u tech news
Volvo
To maintain high performance in the extreme environment, the Volvo EC350E features a hydraulically driven, electronically controlled cooling fan.
Water Sewage & Effluent March / April 2017 33