Hüseyin Suha AKSOY, Kemal ÖZÜDOĞRU

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İnce daneli zeminlerde örselenme

İnce daneli zeminlerde numune örselenmesi nedeniyle, numunenin alındığı zemini temsil etmediği bilinmektedir. Numune örselenmesi özellikle yumuşak zeminlerde deney sonuçlarını daha fazla etkilemektedir. Zemin mühendisliği açısından kohezyonlu zeminlerde numune örselenmesinin iki ana sebebi olduğu kabul edilmektedir. İlki, numune alımı işleminden (delme, numune alma, saklama, çıkartma vs.) kaynaklanan mekanik örselenme, ikincisi ise numunenin üzerinde gerilme boşalması sebebiyle meydana gelen örselenmedir. Zeminde gerilme boşalması nedeniyle meydana gelen örselenme zeminin maksimum kayma gerilmesini ve başlangıç kayma modülünü etkilemektedir. Bu amaçla laboratuvarda yeniden oluşturulmuş numuneler elde edilerek her bir numune için gerilme-şekil değiştirme değerleri ve başlangıç kayma modülü değerleri yardımıyla numune örselenmesinin derecesi belirlenmeye çalışılmış ve elde edilen sonuçlar karşılaştırılmıştır

Disturbance in fine grained soils

In fine grained soils; due to the sample disturbance the specimen can’t represent the soils which exist at the field. Sample disturbance effects test results especially on fine grained soils. If researchers determine the soil properties with higher precision this will reduce the all costs of the geotechnical projects. From the view point of geotechnical engineering; sample disturbance consist of two components, one associated with mechanical disturbance caused by the sampler, handling, etc. and the other is due to the stress release. It is inevitable that mechanical disturbance which occurs because of the stress release, effect especially two of soil parameters; maximum shear strength and initial shear modulus. In this work initial shear modulus and stress-strain relationships will be determined on normally consolidated and over consolidated soil specimens. Reconstituted soil samples are used for laboratory tests. Samples are consolidated at anisotropic and/or isotropic conditions, after consolidation samples were sheared These samples were assumed as normally consolidated soils at the site. Other samples are consolidated at isotropic or anisotropic conditions, after this all loads were released. After one day the sample is loaded with a lower isotropic pressure and sheared in undrained conditions. These samples are assumed as laboratory samples. Maximum shear strength and initial shear modulus of each sample are determined. This data can be used for determining the degree of sample disturbance.
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İTÜ Dergisi Seri D: Mühendislik-Cover
  • ISSN: 1303-703X
  • Yayın Aralığı: 6
  • Yayıncı: İTÜ Rektörlüğü
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Hüseyin Suha AKSOY, Kemal ÖZÜDOĞRU