In 2021, the state-of-the-art, zero-net-energy, New Natural Resources Headquarters for the State of California at 7th and P Street will be 21-stories and home to the second tallest California government agency building along the Sacramento skyline. Turner/AC Martin selected Farrell Design-Build to design and build the Auger Cast Pile (ACP) deep foundation system to make the New Natural Resources Headquarters Go Vertical with Confidence®!
Auger Cast Pile is a “no-vibration” deep foundation support system that will meet the strict structural bearing, lateral, and settlement performance requirements. Historically, the Sacramento area consists of river alluvium with soft and loose silty sand over dense sand and gravel riverbed deposits. Foundation support for this 21-story building consists of over 400 ACPs. ACPs are 24-inches diameter for the 21-story foundation support and 18-inches at the low-rise portion with depths varying from 50-75ft below street level. Engineered concrete grout was injected under pressure through the partial displacement drill for discreet ground improvement to install the ACP. Farrell performed extensive full scale load testing, while utilizing strain gauges and high-dynamic testing to confirm and optimize the ACP design depths.
Farrell also collaborated with Buehler and Geocon to design scenarios where piles could be adjusted in length, where appropriate. Two foundation levels (basement and ground), with different lateral force resisting systems, required specific pile design and engineering to resist the lateral load demand. Farrell engineers performed lateral analysis to check for compatible performance between the two structural systems. Several collaborative iterations were implemented to optimize the pile rebar cage configurations based on the high lateral force resisting system.
Farrell had two crews working with two 200-ton Piling Drill rigs in a shored two-crane shared excavation site, using over 270 cubic yards of pile grout mix per day. Farrell’s crews, Project Manager and Safety Officers were put to the test with managing a 25-man crew, off-hauling the ACP drill spoil, along with unexpected environmental air-quality hazards from the Paradise/Chico fire. The two working pad levels also posed additional construction challenges of installing ACP on two different levels, requiring work around benched areas, dewatering wells, and excavation shoring.
Farrell’s Project Manager, Shane Taroli, collaborated with Turner to align our team with Turner’s daily and weekly tracking systems. Farrell utilized Autodesk BIM 360 for material submittals and digital rig data, Procore to track man hours and daily reports and Turner Tracker for all waste and recycling tickets. Farrell demonstrated unwavering dedication to the project success with rebar cage fabrication reports, ACP installation inspections, daily construction logs, spoil off-haul tickets, grout and truck tickets, fuel consumption records, man hour and safety reports all documented and tracked daily.
Due to the crew size, Farrell was required to provide a full-time on-site Safety Officer, Gene Lawhorn. Gene worked diligently to increase cross-site communication, maintain safety between operator and ground workers, and increase visibility between crane operators, signal persons and daily truck traffic. Farrell’s Activity Hazard Analysis (AHA) procedures were analyzed with Turner and updated AHA procedures were put into place to increase the health and safety for everyone on-site.
In the end, this state-of-the-art building will include a modern 21-story office tower and two separate 2-story low-rise structures. Government employees will enjoy the largest child-care facility constructed by the state, a 300-person auditorium, fitness area, ample parking, retail spaces and a food court. The building will house staff from the California Natural Resources Agency, the Department of Water Resources, the Department of Parks and Recreation, the Department of Fish and Wildlife, the Department of Forestry and Fire Protection, the Department of Conservation and the Wildlife Conservation Board.
Farrell completed the Auger Cast Pile deep foundation under budget and a week ahead of schedule. All in all, Farrell helped the Turner/AC Martin team and the 21-story New Natural Resources building Go Vertical with Confidence®!
Farrell Design-Build Inc. | Sacramento 530.621.4867 | Irvine 949.428.9596