EARTH DAY – EVERY DAY
Regardless of the causes, evidence and impacts of climate change are all around us. Our world is changing. Green initiatives are critical to work towards more sustainable and long-lasting climate solutions. Since its founding on April 22, 1970, Earth Day marks a day to raise awareness of environmental issues facing our planet, promote ways to minimize the disruption to our planet’s fragile ecosystems, and celebrate the global actions to counter the climate crisis.
As another Earth Day anniversary is upon us, we want to recognize the efforts of our manufacturer Tiroler Rohre GmbH (TRM), for their commitment to sustainability. It’s often difficult in the manufacturing and construction industries to strike a balance between supplying and performing construction projects while embracing sustainable practices. As the manufacturer of the TRM Ductile Iron Piling system, TRM places a high priority on sustainability. They are the first cast iron manufacturer to initiate an Environmental Product Declaration (EPD). The raw materials used in the manufacturing of Ductile Iron Piles are from 100% recycled sources. The TRM facility has also implemented numerous measures to enhance a green manufacturing philosophy. Over 3,100 tons of carbon dioxide are saved annually by re-using “waste” heat generated during the melting process. The heat is fed into a local heating network and supplies 650 households. In addition, TRM utilizes the largest photovoltaic system for any Austrian plant to generate sustainable energy for 300 nearby households. DuroTerra is proud of our partnership with TRM and recognizes them for their commitment to sustainable manufacturing and construction.
PROJECT EXPERIENCE – LOS VIENTOS WIND FARM SUBSTATION UPGRADE
Expansion of the Duke Energy Renewables wind farm in rural south Texas required an upgrade to the existing electrical transformers at two separate substation locations. The upgrade involved a planned shutdown that included demolition of the existing drilled shaft-supported mats, installation of new foundations and construction of the expanded substations. The construction timing was critical with a planned one-month outage at each substation location. Deep foundations were required for mat support to transfer the loads below the compressible clay soils extending to 25 feet and into the loose to medium dense sand below. With the limited outage window, any delays in foundation installation were unacceptable.
The project team selected a Ductile Iron Pile solution based on the speed, ease, and flexibility of installation and overall performance. DIPs provided extremely easy adjustment to pile lengths with the Plug and Drive connection if conditions at the site varied. Further, there was no reliance on concrete/grout delivery for pile installation at the remote sites.
A dry installation (no exterior grout) was designed with the Series 170/9.0 piles driven through the clay and into the sand layer to develop capacity through friction along the pile shaft and bearing in the sand. Since the 30-ton design capacity relied only on the strength of the DIP material, no delay for grout curing was needed for load testing. Shortly after installation, load testing on the 50-ft long test pile performed to 60 tons (200%) showed virtually linear response with less than 0.40 inches of movement at the ultimate test load and highly elastic behavior. Installation of up to 36 piles was completed in only 3 days at each of the two sites. The use of the DIPs reduced the deep foundation schedule and potential construction risks to keep the project on schedule and within the substation outage time limits. For more information, check out the project summary.
