This month, DuroTerra’s Contractor Spotlight focuses on Peterson Contractors, Inc. headquartered in Reinbeck, Iowa. Founded in 1964, Peterson Contractors, Inc. (PCI) is a ground improvement and heavy civil/highway contractor. PCI has been a trusted partner on over 9,000 projects throughout the United States. PCI is one of the largest ground improvement installers in the U.S. and is a major player in the heavy civil industry in the Iowa region. PCI has experience in ground improvement, deep foundations, demolition and earth work, earth retention, and bridge building.
“We consider DIPs for any project that requires underpinning or modular pile support,” said Dr. Miriam Smith, PE, PCI’s Director of Product and Market Development. “We often find that it’s a solution that gives us a competitive advantage over traditional deep foundation options, and we appreciate the technical and construction support we receive from DuroTerra. The main advantage is that our crews can install DIPs with smaller equipment on sites with tight access, such as low head room or adjacent structures.”
Peterson Contractors has used Ductile Iron Piles on dozens of projects across the country. Please continue reading for more information about a project where PCI delivered a DIP solution that saved their customer time and money compared to auger-cast piles on a site with constrained access. For more information about Peterson Constractors Inc., visit petersoncontractors.com.
DuroTerra works with a wide variety of geotechnical contractors across the U.S. and Canada – from local contractors to international geotechnical contractors on projects of all sizes. Our engineering and construction representatives can guide you with product information, equipment assessment and setup as well as project feasibility and pricing. Reach out to us today to learn more.
United Fire Group (UFG) planned construction of a new 4-story building addition with only a 4,800 square foot footprint. The addition was positioned between two existing buildings in downtown Cedar Rapids, Iowa. Column loads were up to 700 kips. Soil conditions consisted of 9 to 18 feet of variable fill underlain by sand to depths of 17 to 20 feet followed by stiff to very stiff glacial clay. Limestone bedrock was encountered at depths of 66 to 85 feet below grade. Groundwater was encountered at 10 to 12 feet.
Navigating deep foundation installations on the urban, limited access site with deep bedrock was the main challenge for the project team. Designers originally considered auger-cast piles and drilled shafts for support of the building addition. A Ductile Iron Pile value engineered alternative was proposed to the project team and ultimately selected based on the cost, low vibrations and ease of installation on the tight site.
Project foundation designs were prepared based on a 50 ton working capacity Ductile Iron Pile system. Designers of the piles selected a Series 118/9.0 (118 mm outer diameter with 9 mm wall thickness) to provide adequate structural capacity. The piles were designed to penetrate the fill, sand and glacial clay to terminate on limestone. A total of 63 piles were required to support building loads. Pre-production load testing was performed by Peterson Contractors, Inc. on a pile terminating on rock at a depth of 72 feet. Top-of-pile deflections of 0.32 inches and 0.89 inches were recorded at loads of 50 tons (100% design load) and 100 tons (200% design load), respectively. The pile rebounded to a net deflection of only 0.4 inches, indicating acceptable load test performance. Following excavation of the pile caps, the production piles were installed to rock and terminated upon reaching the set observed in the load test. To learn more about the project, check out the full project summary.