The Earthquake Engineering Online Archive

Residual strength of sand from dam failures in the Chilean earthquake of March 3, 1985

De Alba, Pedro; Seed, H. Bolton; Retamal, Eugenio; Seed, Raymond B.

UCB/EERC-87/11, Earthquake Engineering Research Center, University of California, Berkeley, 1987-09, 47 pages (480.2/A415/1987)

The slope failures at La Marquesa and La Palma dams in the Chilean earthquake, apparently due to liquefaction of loose sand layers near the base of the embankments, are discussed. The dams were low structures and the horizontal movements were substantial; however, configuration of the embankments after the failure suggests that the liquefied soil retained a small but significant strength after liquefaction occurred. Based on field explorations, the characteristics of the liquefied sands before the earthquake occurred are assessed. Results of analyses of the configuration of the slide material are used to evaluate the probable ranges of residual strengths for the liquefied soils.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-87-11.pdf (2 MB)