RENOVA self-performed the construction of a 550-linear-foot sheet pile tieback wall, constructed to allow the prime contractor to safely and effectively excavate radiologically-contaminated soil, while preventing the costly and unnecessary soil disposal caused by sloughing of the excavation walls.

RENOVA initially designed the wall to incorporate helical pile tiebacks. However, heavy debris layers, previously unidentified in the limited geotechnical investigations, were impenetrable by the helical piles. RENOVA proposed an alternate design to account for the subsurface obstructions. The revised design incorporated HP-piles serving as “deadmen” and connected to the sheet pile wall with threaded rod. RENOVA first pre-drilled to 28’ below grade with a down-the-hole hammer, along the entire transect of the sheet pile wall and at each HP pile location, in order to penetrate piling through the heavy debris layers. All piling was installed utilizing a track-mount pile driving rig with a vibratory hammer.

Though previously unidentified subsurface obstructions were encountered, requiring a re-design, RENOVA completed the installation of the sheet pile tieback wall ahead of schedule and with zero health and safety incidents. Additionally, RENOVA received follow-on work, which included the installation of several permanent sheet pile walls on the site as part of the ecosystem restoration. All work was completed safely, while adhering to the schedule and budget.