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Zero-Displacement Lateral Spreads, 1999 Kocaeli, Turkey, Earthquake

2009-01-01
Youd, T. Leslie
Deden, Daniel W.
Bray, Jonathan D.
Sancio, Rodolfo
Çetin, Kemal Önder
Gerber, Travis M.
Three potential lateral spreads exhibited negligible displacements during the 1999 Kocaeli, Turkey Earthquake (M(w)=7.5) even though they were located within 7 km of the fault rupture. These spreads are analyzed to verify and augment current procedures for predicting liquefaction resistance and lateral spread displacement. The sites include Cark Canal and Cumhuriyet Avenue in Adapazari, underlain by fine-grained sediment, and Degirmendere Nose adjacent to Izmit Bay, a steeply sloping area underlain by moderately dense silty sand. The plasticity index and moisture content criteria of Bray and Sancio set forth in 2006 indicate that much of the fine-grained sediment is liquefiable. Even though liquefaction likely occurred, lateral spreading did not occur due either to the dilative nature of fine-grained, sandlike sediments or the inherent strength of claylike sediments. Corrected blow counts, (N(1))(60), in moderately dense sand at Degirmendere Nose range from 15 to 25 blows/30 cm, indicating that liquefaction should have occurred but that the silty sand was too dense and dilative to deform. This finding is consistent with the MLR procedure of Youd set forth in 2002 that identifies liquefiable sands with (N(1))(60) greater than 15 blows/30 cm as resistant to lateral spread during earthquakes with M < 8.