— Drilled shaft foundations are a very established deep foundation technology. They are constructed typically by excavating a 3-12 ft in diameter hole and constructing a cast-in-place reinforced concrete foundation within the hole, typically by placing in the steel reinforcement and subsequently pouring in concrete (very commonly using Tremie pipes). These foundation systems have excellent axial capacity due to a combination of side shearing and end bearing resistance. The size of the foundations also allows for significant resistance to lateral and overturning loads. Drilled commonly reach depths of up to 200 ft and may extend to 300 ft or more. Tampa International Airport Red Side Expansion Hensel Phelps Construction Co. contracted A.H. Beck to install the drilled shaft foundations for their Red Side Terminal expansion at Tampa International Airport. A.H. Beck was tasked with installing 145 drilled shafts, varying in diameter, with depths ranging from 15 to 80 feet socketed into Florida Limestone. There were many challenges posed on the project due to congested work areas, dense utility networks, and low overhead restrictions. Beck utilized one of their CAT based drill rigs tailored for low headroom and demanding rock excavation techniques to install the foundations.  Learn More US 181 Harbor Bridge Replacement For the US 181 Harbor Bridge replacement project in Corpus Christi, TX the two main pylons feature 538-foot towers which are currently partially constructed. Each pylon is supported by 21 shafts measuring 10 feet in diameter, drilled to a depth of 230 feet which were installed by A.H. Beck in 2017/2018. A.H. Beck was brought back in 2023 to install additional shafts to supplement the existing pylon foundations. 48-inch diameter shafts along the north and south perimeter of the pylon footings were installed each to a depth of 230 feet. The shafts were installed underneath previously constructed portions of the bridge deck and in coordination with the ongoing construction of the pylon and bridge deck erection. Learn More