Photo courtesy of HWA GeoSciences HWA and the design team developed an unusual shoring and underpinning system for the renovation of UW’s Savery Hall.

In the University of Washington’s Liberal Arts Quad sits the collegiate-gothic style Savery Hall, constructed between 1917 and 1920. As part of an effort to preserve and modernize its historic buildings, UW scheduled a major renovation of Savery Hall. HWA GeoSciences provided geotechnical engineering, construction inspection and consultation services.

Savery Hall was built on a series of unevenly spaced, heavily loaded column footings on very dense glacial till soils. Any disruption in any footing during construction could have resulted in the destruction of the delicate building facade.

Work required large excavations adjacent to and, in some cases, below the building’s column footings, which required the design of a shoring and underpinning system that would limit footing displacements to no more than the thickness of two sheets of paper.

HWA and the design team developed an unusual shoring and underpinning system that involved an elaborate pre-stressing application, utilizing 6- and 8-inch-diameter micropiles and up to five 200-ton hydraulic jacks that applied footing loads simultaneously to each of the micropiles.

The final design of 27 micropiles of varying dimensions provided vertical support for the footings and temporary lateral support for the excavations. This solution, which went from conception to construction in less than three weeks, enabled complete renovation to critical portions of Savery Hall without damaging the building or setting back the schedule.