The Earthquake Engineering Online Archive

Earthquake-induced liquefaction near Lake Amatitlan, Guatemala

Seed, H. Bolton; Arango, Ignacio; Chan, Clarence K.; Gomez-Masso, Alberto; Grant Ascoli, R.

UCB/EERC-79/27, Earthquake Engineering Research Center, University of California, Berkeley, 1979-09-01, 34 pages (715.2/S43/1979)

This report presents the results of a field and laboratory investigation of the extensive area of liquefaction which occurred at La Playa on the shore of Lake Amatitlan in the Guatemala earthquake of 1976. The investigation leads to the following conclusions. The soil in which liquefaction occurred was a layer of sand containing particles of pumice which occurred between depths of about 5 to 70 ft or more below the ground surface. It was covered by a surficial layer of lightweight pumice sand; and because of the pumice particles in the liquefied layer, its total unit weight had the relatively low value of about 90 lb/cu ft. In spite of the fact that the sand is somewhat lighter in weight than sand deposits which have liquefied in other earthquakes, its liquefaction characteristics are apparently influenced by the same factors as other sand deposits and its overall behavior is consistent with that exhibited by other sands. The penetration resistance of the sand at the boundary between liquefied and non-liquefied zones is in good accord with previously developed empirical correlations between liquefaction potential and the standardized penetration resistance at which liquefaction can just be expected to occur. The behavior of the sand in the liquefied and nonliquefied zones was consistent with experimental-analytical predictions of liquefaction potential based on the results of cyclic loading triaxial compression tests performed on undisturbed samples to evaluate the liquefaction characteristics of the sand and conventional procedures used in conjunction with this type of test data to evaluate liquefaction potential. The high degree of liquefaction at the La Playa site was probably caused in large measure by the lightweight nature of the pumiceous sands. The results of the investigation provide an extremely useful case history in which field data on soil characteristics in an earthquake-liquefied zone and a non-liquefied zone can be correlated with field performance.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-79-27.pdf (4 MB)