Coastal Foundation Solutions had to deploy our specialty equipment to proceed with this stabilization project. We launched our 26-foot aluminum barge from the condominium parking lot into Big Hickory Pass with a 75-ton crane. Next, our Kobelco mini-excavator was flown unto the barge to facilitate installation of helical compression piles and helical tie-back anchors.
The engineer designed a system of hydraulically-rotated helical piling to permanently stabilize a new retaining wall and spread footing. In addition, the existing concrete seawall required supplementary helical anchors.
The compression piers were advanced to depths of approximately 17-21 feet to bear below the organic material and achieve a design working load of 10 kips per pier. These piling would support the new spread footing for the retaining wall. A hydraulic drive rotated the supplementary 6”-6”-6” triple-helix lead section, which was installed through a six-inch diameter cavity opening. Coastal Foundation Solutions utilized combinations of specialized concrete core bits to gain access through existing 6” thick vertical seawall.
The cavity was filled with a 6” polystyrene foam plug and a H.D.E.P. membrane to prevent soil loss after helical anchor installation.
Coastal Foundation Solutions was also tasked with eliminating soil migration through the existing seawall seams. This methodology entailed scrapping the marine organisms off the concrete seawall and seams. We then installed a backer rod that has a closed cell exterior into the seams which is permeable to allow water to escape but contain soil properties. A ¼” P.V.C. panel was the attached to the wall and fastened with ¼” 316 Stainless Steel anchors.
The project entailed utilization of thirty (30) helical anchors to be installed in tension and compression.
Helical piles were installed by Coastal Foundation Solutions (CFS), a Certified Installer of Seawall Savers and Chance Helical Foundations Systems.
Ten (10) CHANCE 2 7/8” round shaft helical piles with an 8”-10” 12” triple-helix lead section were installed with a 6K Eskridge drive head. The Kobelco excavator progressed the extensions to lengths on the order of 17-21 feet to achieve final installation torques. The ultimate capacities of at least twice the design working tension load of 10 kips
Twenty (20) “CHANCE” (RS2875.203) round helical extensions were installed to corresponding capacities to secure tension load of 10 kips.
The helical foundation pilings were affixed with a galvanized 7’ by 7” termination cap.
Twenty (20) Seawall Saver SS150 (1.5-inch square bar) helical piles with a 6”- 6”- 6” triple-helix lead section were installed with a 6K Eskridge hydraulic drive head. The mini excavator rotated the square extensions to lengths on the order of 15 to 21 feet to achieve final installation torques. The ultimate capacities of at least twice the design working tension load of 12 kips
Thirty-one (31) “Seawall Saver” square shaft helical extensions were installed to corresponding capacities.
The helical tension pilings were affixed with a 1” galvanized rod, that is attached to a galvanized 7” by 18” structural steel “C” channel.