Archived site
Johnson
The Challenge
A failing parking structure replaced in place between two fully occupied towers
The Orchard Complex garage had reached the end of its service life and was showing signs of structural deterioration that made replacement unavoidable. The problem was its location: directly between two fully occupied towers, with an active public plaza above and tenants in both buildings who hadn't been given any notice of disruption. Demolition and reconstruction had to proceed with the towers in full occupancy and the plaza in active use. The shoring scheme for the adjacent towers had to be designed before demolition could begin, since removing the garage would temporarily eliminate lateral support it had been providing to the existing foundations.
Our approach
We developed a segmented demolition and reconstruction sequence that divided the garage into sections small enough that the remaining structure could always carry the adjacent tower loads during work on any given segment. Temporary shoring was designed and installed before any demolition began, with each shore carrying the tributary loads from the occupied towers at a conservative factor of safety. The plaza deck above was re-shored section by section in parallel with the work below, staying open to foot traffic throughout. New construction followed immediately behind demolition in each segment, minimizing the time any portion of the site was in a temporary state.
The outcome
The replacement garage was delivered with both towers fully occupied and the plaza open throughout the entire construction period. Zero tenants were relocated, and the tower occupants reported minimal disruption. The new structure added 420 stalls on the same footprint with a more efficient layout than the original, and the plaza above was restored to better condition than before construction began. The project demonstrated that infrastructure replacement in a live urban campus is a sequencing and engineering problem, not an occupancy problem.
2
Occupied towers adjacent
0
Tenants relocated
420
Stalls replaced
"Two full towers stayed occupied through the whole replacement. Our tenants barely noticed."
Thomas Reed, COO, Orchard REIT
