İNCE DANELİ ZEMİNLERDE TEKRARLI YÜKLER ALTINDA BOŞLUK SUYU BASINCI OLUŞUMLARI VE MALZEME DAVRANIŞI

Bu çalışmada, ince daneli zeminlerde tekrarlı yüklemeler sonucu oluşan boşluk suyu basınçlarının, zemin göçme davranışına etkisi incelenmiştir. Bu amaçla arazide farklı noktalardan yer altı su tablasının altından alınan, bozulmamış orta-yüksek plastisiteye sahip kil zeminler üzerinde bir grup dinamik üç eksenli deney gerçekleştirilmiştir. İzotropik gerilme koşulları altında gerçekleştirilen deneylerde iki farklı yükleme tipi uygulanmıştır. Numuneler için göçme kriteri ±% 2.5-3 birim kayma deformasyon seviyesi kabul edilmiştir. Yükleme sırasında oluşan boşluk suyu basıncı artışları ve göçme anındaki boşluk suyu basıncı değerleri farklı zemin parametrelerine göre karşılaştırılmıştır. Tekrarlı kayma gerilme değerine bağlı olarak boşluk suyu basıncının zemin numunesinin mineralojisiyle önemli ölçüde değiştiği gözlenmiştir. Pratik amaçlar için boşluk suyu basıncı modeli önerilmiştir.

Anahtar Kelimeler:

Dinamik üç eksenli, boşluk suyu basıcı, kil zemin

GENERATION OF PORE PRESSURE AND MATERIAL RESPONSE OF FINE GRAINED SOILS UNDER CYCLIC LOADS

This paper discusses the effect of pore-water pressure of fine-grained soils on failure behavior. For this purpose a series of dynamic triaxial tests were performed on natural medium-high plasticity clay specimens taken from the in-situ boreholes under groundwater levels. Two different dynamic loading sequences were used under isotropic stress conditions. In terms of cyclic strain amplitude the failure criteria is assumed as ±2.5%. Excess pore water pressure accumulation was recorded at the time of failure and were analyzed considering different soil parameters. It has been concluded that, besides the shear stress value, the pore water pressure behaviour has changed significantly by mineralogy of the soil sample. For practical purposes, a pore water pressure model is proposed.

Keywords:

Dynamic triaxial test, pore water pressure, clay soil,

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