Stanford University, Crothers Memorial Hall
This 1940’s era dormitory was constructed with an unconventional latticed steel stud system that relied on the plastered interior room demising walls as the primary transverse vertical lateral force resisting system. This archaic (and ill advised) structural system was deemed inadequate to provide sufficient seismic resistance. The original strengthening scheme described in an evaluation report prepared by others, recommended removing all existing roof tiles so the straight sheathed roof could be sheathed in new plywood; additional recommendations called for the removal of all exterior stucco so that the exterior walls could also be sheathed.
By utilizing performance based techniques, Hohbach-Lewin was able to devise a scheme which eliminated the need for both of these costly retrofit measures. Intermittent wood framed cross walls were introduced into the attic space and a system of discreet and strategically located concrete shear walls were introduced in to the building footprint. To account for the low overhead clearance in the basement, the new concrete walls were supported by a network of new micro pile supported grade beams.