Alberici’s Olin Library project was recognized in at the AGC of Missouri’s Keystone Awards gala on November 8, bringing home the top prize in Building Project $10-$25 million category. Members of the Alberici team, as well as representatives from Washington University and the design team, were on hand to celebrate.
This marks Alberici’s 17th Keystone Award in the program’s 21-year history.
The Olin Library project involved an “inverted vertical expansion” – a two-story, 30,000-square-foot underground addition – and renovation of 10,000 square feet of the existing library. Part of the renovation including erecting a steel tower inside an existing glass atrium.
This type of underground expansion, constructed while the library remained in 24/7 operation, was complex enough, but the team soon encountered a major challenge. During excavation, they found that the existing piers (which were to be used for the structure of the expansion) terminated up to six feet above where they were shown on the as-built drawings, due to sub-soil conditions. When the bells of the piers started appearing during excavation, crews immediately stopped work to allow for exploration. After presenting multiple options to Washington University, the team began to to replace all concrete piers with new footings and structural steel columns.
This option required that the team shore the building, to hold it in place while the old concrete piers were removed and the new columns were installed. Alberici used a hydraulic jacking system mounted on heavy-duty shoring towers – each with a load capacity equivalent to roughly 400 kips or 400,000 pounds – to temporarily support the building. Once the building load was transferred to the towers, they removed the existing concrete piers, poured new footings, and installed the new structural steel columns. Once the new steel columns were erected, the load
was transferred out of the temporary shoring towers.
This remediation work was done in five phases, all while keeping the library spaces above open to students and staff. The engineers compared it to hosting a dinner party and replacing the legs of the table during the meal without the diners noticing the work.
The newly transformed library includes collaboration and study spaces, new classrooms, a coffee shop, and space for the University’s Special Collections.