The Lloyd Block development was designed to occupy three city blocks with an existing 17-story concrete building, a new three-story below-grade parking structure that would span the entire site, plus new office and condominium towers.
The shoring system for this development consisted of soldier piles, temporary tiebacks, pressure treated lagging, and underpinning piles. Soldier piles were placed along the perimeter of the site in drilled shafts with structural concrete toes and lean concrete back II. For the underpinning work, 64 temporary tiebacks were drilled through an existing retaining wall from inside the existing parking garage to hold the retaining wall in place while the parking garage was demolished. After demolition of the parking garage, soldier piles were installed at the base of the retaining wall so that an additional level below grade could be excavated for the new 3-story parking garage. The remainder of the site was traditionally shored to the bottom of the excavation.