Manzanita Hall is one of three remaining buildings on the University of Nevada, Reno, campus that were constructed prior to 1900. Originally named the Girls’ Cottage, Manzanita Hall was built in 1896 and was used to house 97 women in double and single rooms. Architecturally, it a created a Victorian atmosphere and offered a spacious student lounge, complete with a grand piano and a spectacular view of Manzanita Lake.
Several years ago, the hall was deemed seismically inadequate, and the electrical, plumbing and HVAC systems were likewise found to be seriously outdated and insufficient for modern college life. These structural deficiencies necessitated its closure in 2015.
Unreinforced Masonry buildings in moderate to high seismic areas can be a disaster in waiting. These types of structures have little or no ductility capacity (reference the recent “Building Drift – Do You Check It?” blog post for a discussion on ductility) required for structures to prevent loss of life in a seismic event. Many of these buildings are in densely populated areas, have historical meaning, and can be costly to retrofit. Fortunately, there are tools available for engineers to assess and design the needed retrofits to mitigate the potential loss of life and increase the seismic resiliency of these buildings.
ASCE 31-03, Seismic Evaluation of Existing Buildings, and ASCE 41-06, Seismic Rehabilitation of Existing Buildings, are two reference standards that are referenced in the 2012 International Existing Building Code (IEBC). (It should be noted that both of these reference standards are currently being combined into one document – ASCE 41-13.) Although ASCE 31 and 41 provide assistance to engineers in determining minimum seismic retrofits for these brittle structures, it is recommended that design of the retrofits be performed by a qualified engineer with experience in working with these types of brittle structures.
Currently the 2012 IEBC has been adopted in 39 states in the U.S. and several other areas (see reference map below).