Towers & Columns
Foundations for Pre-Fabricated Metal Buildings
The capacities and capabilities of Structural Foundations are suitable for nearly all pre-fabricated metal building applications. These structures particularly benefit from Structural Foundations' high uplift resistance, often the greatest force on a pre-fabricated metal building. Where helical piers / screw piles offer only marginal uplift resistance and require multiple installations beneath each building column, individual Structural Foundations provide uplift resistance either nearly equivalent or equivalent to the foundation's bearing capacity. Another common approach is the use of massive concrete spread footers, with 1,000 cubic yards of concrete not uncommon for buildings in the 25,000 square-foot size range. In this approach, the total installed cost of excavating, form building, rebar installation, concrete delivery and pouring, and concrete finishing can easily exceed $350 per cubic yard. In many U.S. locations, including inland areas not subjected to hurricane-force winds, pre-fabricated metal buildings must now be built to withstand 120 mph wind loads and induced uplift, much greater wind pressures than the former 90 mph code standard. Structural Foundations provides the superior solution, with less foundation material and cost than deep foundations, piles, and large concrete pours for these applications.
Foundations for Industrial Greenhouses
Like other pre-fabricated building structures, industrial greenhouses must resist high uplift forces. Cost benefits of Structural Foundations for these applications derive from high uplift resistance of each individual foundation, comparatively smaller foundations for low bearing capacity requirements, and the ability to quickly and easily bolt or weld the greenhouse structure to the steel foundations.
Foundations for Office Buildings
Ultimate column loads for low-rise commercial office buildings often range from 50 kips to 300 kips. Structural Foundations are suitable for many of these applications, even for mid-rise buildings up to five stories. Where deep foundations would commonly be specified for these applications, Structural Foundations can provide a total cost savings of up to 50%. Commonly, h-piles are driven to bedrock when these buildings are located in poor soils. In many areas of the U.S., especially those near major bodies of water, bedrock can be located over 100 feet below ground surface. This condition is especially common in lower Michigan, where Structural Foundations has several large installations. Typically, three h-piles are driven beneath each building column location. In a condition where bedrock is 50 feet below ground surface, total installed cost for h-piles at a single building column location is often $7,500 and twice the cost if bedrock is 100 feet below ground surface. Structural Foundations competes especially well in these applications, not only on installed cost, but also for providing the capability to directly weld the steel columns of the building to our steel foundations, thereby eliminating the need to pour concrete pile caps as done with h-piles.
Foundations for Houses
Houses built in poor soils often require the use of deep foundation systems and grade beams for adequate foundation support. Conventional approaches include the use of timbers, helical piers / screw piles, aggregate piers, and where more economical, ground improvement techniques (excavation and compacted fill). Where ground improvement is uneconomical, helcial piers / screw piles or aggregate piers have become the preferred choice, especially over the past 30 years. However, the capacity of helical piers / screw piles requires that they be numerous for the wall and column loads of these structures, while aggregate piers require very large equipment for installation and have high equipment mobilization costs. Structural Foundations support multiple houses in poor soil areas, saving cost, accelerating installation completion, and not requiring any heavy equipment or excavation disposal.
Foundations for Oil and Water Storage Tanks
Oil and water storage tanks are typically supported by concrete ring-wall foundations that are constructed over piles that terminate in bedrock. Port facilities are common sites for oil storage tanks, on the nation's ocean and Great Lakes coasts. Most of these sites have poor soil conditions and bedrock tens of feet below ground surface. Water storage tanks are found nationwide. Structural Foundations provides an alternative to pile construction, with our individual steel foundations capable of 300 to 600+ kips across a spectrum of soil strengths.
Foundations for Conveyors and Transfer Towers
Industrial conveyors and transfer towers typically are constructed upon concrete foundations. These are large concrete pours, especially where either, or a combination of, high moment forces and poor soils are present. Remote sites with poor road access make concrete supply and delivery more challenging and expensive. Even where soil conditions are moderately strong and moment forces aren't high, Structural Foundations can provide a substantial cost savings. With foundation installation achieved in mere minutes to an hour, negligible vibration, no disposal for excavated spoils, no cure time, and the ability to weld or bolt to the foundation immediately, Structural Foundations can achieve additional cost and time savings.
Foundations for Power Substations & Transmission
Providing grounding capability without need for expensive copper grounding mats, Structural Foundations offer substantial cost savings for power substation applications. Structural Foundations also provide resistance to high moment loads common at power substations. For power transmission, and especially where steel monopoles are used, Structural Foundations are the cost-saving solution in poor soils, at corners, and where concrete pours are especially large.
Foundations for Signal Towers
Monopole and tri-legged signal towers are ubiquitious. Structural Foundations support a dozen signal towers in West Virginia! Traditional installations utilize large concrete pours to provide sufficient dead weight. Structural Foundations are designed to attach directly to the steel towers, and our proprietary high-capacity anchors are left in place after installation for greater moment and uplift resistance. Independent validation has been conducted on these installations years after installation, concluding that bearing capacity and uplift resistance were equivalent and unchanged over time.
Foundations for Wind Turbines
Wind turbines are among structures that must withstand the highest torsional and moment forces. Structural Foundations are a certified foundation solution for small wind installations. In 2004, the National Wind Technology Center (NWTC) of the U.S. Department of Energy validated Structural Foundations' performance for small wind installations, defined as those up to 300 kW (0.3 MegaWatt). Wind turbines in Colorado, Ohio, and Michigan are supported by Structural Foundations.
Foundations for Retaining Walls
Structural Foundations' moment foundations resist slide and overturn forces, providing an ideal foundation for retaining walls of all types, including cast-in-place concrete, block, and soldier pile. Common practice is the use of deep driven pipe or h-piles, accomplished at great expense, or the use of deep auger-cast concrete caissons. Structural Foundations achieves capacities equivalent or greater than these methods, but at shallow depths and with our fast hydraulic installation process. Structural Foundations has been in such high demand for retaining walls that we not only install foundations for them, but actually construct entire turnkey soldier pile retaining walls. See more here!
Foundations for Contaminated Soils & Brownfield Sites
Contaminated soils and capped contaminated fills are best left undisturbed in construction. Deep foundation installation disturbs these soils, both at the surface and beneath. Structural Foundations are an ideal alternative. Excavation of the small-diameter hole is usually not more than 10 to 12 feet deep. Excavated materials (spoils) are returned to the foundation after installation, requiring no disposal. The shallow depth of Structural Foundations and their excavations doesn't threaten the integrity of most caps and liners, as these often are buried deeper. Many brownfield sites consist of loosely consolidated fill material, which provides inferior bearing capacity that would commonly necessitate a deep foundation solution for building construction. However, Structural Foundations are highly economical for poor soils, providing high and verified bearing capacity.