Liquefaction analysis for rubble mound breakwaters

Buildup of pore pressure induced by cyclic loads because of earthquake, wave or shocksthen decreasing of effective stress and become zero is defined as liquefaction mechanism.In this study liquefaction of soil induced by earthquake and wave and calculationmethods are examined.Liquefaction induced by wave is generated mainly by two different mechanism. First oneis residual liquefaction by the buildup pore pressure, second one is momentaryliquefaction by the upward vertical pressure gradient in the soil during the passage of awave trough. The wave-induced shear stresses in the soil, the pore pressure and theground-water flow are essential components of the liquefaction process. It?s possible tomake a decision about liquefaction potential when these components are found.By means of developments in earthquake engineering in last 15 years, the specification ofground motions can be defined better and used for design. Great progress has been gotespecially in using of dynamic analysis methods and prediction of liquefaction. On theother hand the concept of liquefiable soil or existence of liquefiable layers in the soil thatis examined is still a discussion subject. However liquefaction potential induced byearthquake can be calculated by using methods that have been accepted commonly.Japanese grain size distribution-SPT N number, Seed et.al (1984-1985), Cetin and Seed(200-2001) methods are used in this study for examining of liquefaction potential inducedby earthquake. The standard penetration test results (N numbers) getting from site arecorrected for procedure, effective stress and fine material content in each method byusing same or different correlations. The liquefaction effect on Ere:li Fishery Port thathas been suffered damage during 17thAugust, 1999 Earthquake is examined bycomparing of three methods in this study also.Key words: Liquefaction mechanism, wave breakers, sea structures, undersea pipelines,pore pressure, shearing stress, effective stress, ground acceleration, fine material content,correction for procedure, magnitude scaling factor, high overburden stress correctionfactor, cyclic stress ratio, cyclic resistance ratio, probability of liquefaction, liquefiablesoil, safety factor.JURY:1. Prof.Dr. YalçAn YÜKSEL (Supervisor) Date: 26.10.20052. Prof.Dr. M.Emin KARAHAN Page: 1453. Doç.Dr. Esin ÇEVHK