Discussion of "Liquefaction-induced lateral spreading at Izmit Bay during the Kocaeli (Izmit)-Turkey earthquake" by K. Onder Cetin, T. Leslie Youd, Raymond B. Seed, Jonathan D. Bray, Jonathan P. Stewart, H. Turan Durgunoglu, W. Lettis, and M. Tolga Yilmaz

Bakır, Bahadır Sadık
Saglam, Selman
This paper presents a study of liquefaction-induced lateral ground displacements along the coast of Izmit Bay during the 1999 Kocaeli (Izmit)-Turkey earthquake. The paper discusses: (1) observed ground displacements after the earthquake, (2) the results of field investigations by means of borings and in situ index tests, including standard penetration tests, static cone penetration tests, and piezocone tests, (3) analyses of expected lateral displacements using two empirical models and one semiempirical model, and (4) comparisons between observed and calculated lateral ground movements. The three models provide inconsistent predictions of observed lateral ground displacements, with one method overpredicting and two methods both overpredicting and underpredicting observed lateral ground displacements by large amounts. Thus, it appears that there is a need for improved engineering tools for prediction of small to moderately significant lateral ground displacements (lateral displacements of approximately 0.1–2.5 m) at soil sites with similar ground characteristics to the case history sites presented herein.