Performance-Based Seismic Assessment of Unreinforced Masonry Buildings in New York City
Experimental test setup
Researchers from MCEER are collaborating with the Structural Engineers Association of New York (SEAoNY) and the International Masonry Institute (IMI) to investigate the seismic vulnerability of masonry walls that comprise New York City’s large stock of aged brownstones.
MCEER’s research team built two unreinforced masonry walls using materials typical of late 19th – early 20th Century construction techniques; one wall was reinforced with steel rods and bolts that connected the flooring to the wall, and the other was not. The walls were subjected to two sets of earthquake ground motions; first from the 5.8 magnitude 2011 Virginia earthquake, which caused both walls to move, but did not cause noticeable damage. The second set of ground motions was from the 6.3 magnitude 2011 New Zealand earthquake. This time, the parapet on the unreinforced wall collapsed, and the reinforced wall suffered some damage but remained standing. An unexpected result was the sliding failure that occurred at the connection of the floor diaphragm on the reinforced wall.
The experimental testing, part of a larger project to develop and validate numerical models to be used for seismic vulnerability assessments, provided much-needed experimental data on out-of-plane seismic behavior of masonry walls with parapets. In addition, new information about the wall-to-diaphragm connection has been collected and will be used to estimate the effectiveness of this type of retrofitting technique.
Deformed shape of archetype building (left), deformed shape of one-story unreinforced masonry structure (right)
The project team includes MCEER investigators Andrew Whittaker and Amjad Aref, both of the Department of Civil, Structural and Environmental Engineering (CSEE), University at Buffalo, Gilberto Mosqueda, University of California at San Diego (formerly of CSEE, UB), and CSEE Ph.D. candidate and Fulbright Scholar Juan Aleman. In addition to SEAoNY and IMI, the International Union of Brick Layers & Allied Craft Workers—Local #3 NY, United Materials LLC, Scranton’s Thruway Builders Supplies and Reclaim Syracuse Inc. collaborated on the project.
Unreinforced masonry walls, typical of those used in New York City, were tested on February 19, 2013, in the Structural Engineering and Earthquake Simulation Laboratory (SEESL) at the University at Buffalo
Juan Aleman, PhD student and Fulbright scholar, describes upcoming shake table testing of the wall specimens.
Video by UB Communications, February 11, 2013
UB Researchers Simulate Earthquakes on New York City Buildings
Video by UB Now, February 22, 2013-02-25
Aleman J.*, Mosqueda G., Whittaker A., (2013), "Performance-Based Seismic Assessment of Unreinforced Masonry Buildings in New York City," 2013 EERI Annual Meeting, Seattle, Washington, February 12-15,2013.
Aleman J.*, Mosqueda G., Whittaker A., (2013), "Performance Based Seismic Assessment of Unreinforced Masonry Buildings Considering Out-of-Plane Loading," The 12th Canadian Masonry Simposium, Vancouver, Canada.