Effect of Soft Soil Model Parameters on Soil Behavior

Öz

Soft soils such as clays have a high porosity and demonstrate a high compressibility compared to other type soils. In oedometer testing, normally consolidated clays behave up to ten times softer than normally consolidated sands [1]. Clay soils have very low permeability which is highly important to govern consolidation rate. In this study, first task has been to investigate the primary consolidation behaviour of soft clay by using a large-scale laboratory oedometer test. The reconstituted specimen of kaolin clay was used to represent the soft clay. The kaolin powder was mixed at a water content of about 1.5 times the liquid limit and has been consolidated by the axial stress of 30kPa. Secondly, the effect of the soil parameters obtained from standard laboratory tests on soft clay behaviour was researched with numerical finite element analysis computations in Plaxis 2D. Soft Soil material model was utilized during the finite element computations and input parameters were calculated from standard laboratory tests. The simulations demonstrate that it is very important to determine appropriate model parameters for modelling soft soil behaviour.

Anahtar Kelimeler

• Consolidation,Modelling,Oedometer test,Plaxis,Soft soil model

Yumuşak Zemin Model Parametrelerinin Zemin Davranışına Etkisi

Öz

Kil gibi yumuşak zeminler yüksek poroziteye sahiptir ve diğer zemin türleri ile karşılaştırıldığı zaman yüksek sıkışabilirlik göstermektedir. Ödometre deneyinde, normal konsolide killer normal konsolide kumlara göre on kat daha yumuşak davranmaktadır [1]. Kil zeminler çok düşük permeabiliteye sahiptir ve permeabilite konsolidasyon oranının idaresinde oldukça önemlidir. Bu çalışmada ilk olarak yumuşak kilin birincil konsolidasyon davranışı büyük ölçekli bir laboratuvar oedometre deneyi kullanılarak incelenmiştir. Yumuşak kili temsil etmesi için yeniden yapılandırılmış kaolin kili kullanılmıştır. Kaolin tozu likit limitin 1,5 katı kadar su ile karıştırılarak 30kPa değerinde bir eksenel basınç ile konsolide edilmiştir. Çalışmanın ikinci kısmında, klasik laboratuvar deneylerinden elde edilen zemin parametrelerinin, yumuşak zemin davranışına etkisi Plaxis 2D sonlu eleman hesapları ile araştırılmıştır. Sonlu eleman hesaplarında Yumuşak Zemin Modeli kullanılmıştır ve model parametreleri standart laboratuvar deneylerinden elde edilmiştir. Simulasyonlar uygun model parametrelerinin belirlenmesinin yumuşak zemin davranışının modellenmesinde oldukça büyük bir öneme sahip olduğunu göstermektedir.

Anahtar Kelimeler

• Konsolidasyon,Modelleme,Oedometre deneyi,Plaxis,Yumuşak zemin modeli

Kaynakça

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