Evaluation of Excess Pore Water Pressure Build-up During Cyclic Triaxial Tests on a Non-plastic Silt

Year 2018, Volume:6 No:2 (2018) (Special Issue: IMCOFE 2017), 513 - 524, 06.04.2018

Eyyüb Karakan , Nazar Tanrınian Alper Sezer

Abstract

Cyclic
loading is responsible for pore water pressure buildup, which may later cause liquefaction
and surface settlements. Recent studies emphasize that as the pore water
pressure equalizes to initial confining stress, cyclic stress ratio and
relative density of soil play a great role in buildup of excess pore water
pressure. Nonetheless, pore water pressure is also a function of axial strain.
In this regard, cyclic triaxial tests were carried out to evaluate the pore
water pressure buildup behavior of a nonplastic silt. It was aimed to determine
the dependence of pore water pressure, double amplitude of axial strain and
number of cycles on cyclic stress ratio. In this scope,  stress-controlled
cyclic triaxial tests at a loading frequency and confining pressure of 0.1 Hz
and 100 kPa were carried out on saturated samples. It was understood that number
of loading cycles leading to liquefaction were decreased by increases in cyclic
stress ratio and relative density. The data obtained in this study, bringing an
insight into pore water pressure build-up behavior of nonplastic silts, can be
used for practical purposes.  

Keywords

cyclic triaxial tests, nonplastic silt, excess pore water pressure

Plastik olmayan bir silt zemin üzerinde yapılan çevrimsel üç eksenli deneyler sırasında oluşan aşırı boşluk suyu basıncının değerlendirilmesi

Abstract

Çevrimsel yükleme, boşluk suyu basınçlarında artışlar meydana getirerek,
daha sonra sıvılaşma ve oturmalara yol açabilmektedir. Yakın zamanda yapılan
çalışmalarda, boşluk suyu basıncının ilksel çevre basıncına eşit olması durumunda,
çevrimsel gerilme oranı ve zeminin izafi sıkılığının aşırı boşluk suyu
basıncının gelişiminde büyük rolü olduğu vurgulanmaktadır. Bununla birlikte,
boşluk suyu basıncı aynı zamanda eksenel deformasyonun bir fonksiyonudur. Bu
bağlamda, plastik olmayan bir silt zeminin boşluk suyu basıncı gelişim
davranışının değerlendirilebilmesi için bir dizi çevrimsel üç eksenli basınç
deneyi yapılmıştır. Deneyler ile, boşluk suyu basıncı, çift genlikli eksenel
deformayon ve çevrim sayısının çevrimsel gerilme oranına bağımlılığı
araştırılmıştır. Bu amaçla, suya doygun örnekler üzerinde gerilme kontrollü
çevrimsel üç eksenli basınç deneyleri 0.1 Hz frekansta ve 100 kPa çevre
basıncında tatbik edilmiştir. Sıvılaşmaya neden olan çevrim sayısının, artan
çevrimsel gerilme oranı ve izafi sıkılık ile azaldığı elde olunmuştur.  Çalışmada elde edilen veriler, plastik
olmayan silt zeminin boşluk suyu basıncı gelişim davranışıbı
detaylarlandırmaktadır ve pratik amaçlarla kullanılabilir.  

Keywords

Dinamik üç eksenli deneyler, plastik olmayan silt, aşırı boşluk suyu basıncı

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