Skip to main content
U.S. flag

An official website of the United States government

An engineering rock classification to evaluate seismic rock-fall susceptibility and its application to the Wasatch Front

January 1, 1993

Investigations of earthquakes world wide show that rock falls are the most abundant type of landslide that is triggered by earthquakes. An engineering classification originally used in tunnel design, known as the rock mass quality designation (Q), was modified for use in rating the susceptibility of rock slopes to seismically-induced failure. Analysis of rock-fall concentrations and Q-values for the 1980 earthquake sequence near Mammoth Lakes, California, defines a well-constrained upper bound that shows the number of rock falls per site decreases rapidly with increasing Q. Because of the similarities of lithology and slope between the Eastern Sierra Nevada Range near Mammoth Lakes and the Wasatch Front near Salt Lake City, Utah, the probabilities derived from analysis of the Mammoth Lakes region were used to predict rock-fall probabilities for rock slopes near Salt Lake City in response to a magnitude 6.0 earthquake. These predicted probabilities were then used to generalize zones of rock-fall susceptibility. 

Publication Year 1993
Title An engineering rock classification to evaluate seismic rock-fall susceptibility and its application to the Wasatch Front
DOI 10.2113/gseegeosci.xxx.3.293
Authors E. L. Harp, M.A. Noble
Publication Type Article
Publication Subtype Journal Article
Series Title Bulletin of the Association of Engineering Geologists
Index ID 70017865
Record Source USGS Publications Warehouse
Was this page helpful?