Dolgu ile İyileştirilen Zeminlerde Dolgu ve Temel Parametrelerinin Taşıma Gücüne Etkilerinin Araştırılması

Year 2021, , 629 - 647, 15.12.2021

Bahadır Ok , Talha Sarıcı , Murteda Ünverdi , Hüseyin Çolakoğlu

https://doi.org/10.31466/kfbd.979559

Abstract

Tabakalı zeminlerin nihai taşıma kapasitesinin belirlenmesine yönelik birçok teorik yaklaşım ortaya konulsa da zeminlerin karmaşık yapılarını basitleştirmek için yapılan kabuller özellikle tabakalı zeminlerin taşıma kapasitelerinin doğru olarak belirlenmesini zorlaştırmaktadır. Bu sebeple, zeminlerin davranışının belirlenmesinde sonlu eleman yöntemi kullanılması son yıllarda popülerleşmektedir. Bu çalışma kapsamında, sonlu elemanlar yöntemini kullanan Plaxis programı kullanılarak tabakalı zeminlere oturan dairesel bir temelin gerilme-şekil değiştirme davranışları detaylı bir şekilde incelenmiştir. Tabakalı zeminler, arazide yapılmış bir gurup plaka yükleme deneyi dikkate alınarak, alt kısımda kohezyonlu zayıf bir zemin ve üst kısımda ise dolgu olarak düşünülen kohezyonsuz farklı zeminlerden oluşturulmuştur. Plaxis ile yapılan sayısal analizler ile arazide yapılan deney sonuçları karşılaştırılarak modelin güvenilirliği kanıtlanmıştır. Model doğrulandıktan sonra, temel çapı, dolgu yüksekliği ve dolgunun mukavemeti gibi parametrelerin yük deformasyon davranışına etkisini belirlemek için parametrik çalışmalar gerçekleştirilmiştir. Ayrıca çalışma sonuçlarındaki ölçek etkisi ortaya konmuştur. Analiz sonuçları tabakalı zeminlerin nihai taşıma kapasitelerini karşılaştırmak için boyutsuz taşıma kapasitesi oranları şeklinde sunulmuştur. Taşıma kapasitesi oranları incelendiğinde, temel çapı, dolgu kalınlığı ve dolgunun mukavemeti arttıkça taşıma kapasitesi oranının da arttığı belirlenmiştir. Örneğin, içsel sürtünme açısının artmasıyla kalın bir dolgunun taşıma kapasitesi oranında 3,37 kat artış elde edilmiştir. Bununla birlikte temel çapının küçülmesi ile birlikte dolgu kalınlığı ve dolgunun mukavemeti arttıkça ölçek etkisinin arttığı görülmüştür.

Keywords

Tabakalı zeminler, Dolgu ile zemin ıslahı, Sonlu elemanlar analizi, Plaka yükleme deneyi

Thanks

Yazarlar analiz programının kullanımı konusunda desteğinden dolayı Çukurova Üniversitesinden Prof. Dr. Abdulazim YILDIZ’a teşekkürlerini bildirirler.

Investigation of the Effects of Filling and Foundation Parameters on Bearing Capacity in Soil Improved by Filling

Abstract

Although many theoretical approaches have been put forward to determine the ultimate bearing capacity of layered soils, the assumptions made to simplify the complex structures of soils make it difficult to determine the bearing capacity of layered soils accurately. As a consequence, the use of the finite element method in determining the behavior of soils has become popular in recent years. In this study, the stress-strain behaviors of a circular foundation settling on layered soils were investigated in detail by using the Plaxis program, which uses the finite element method. Layered soils were formed from weak cohesive soil at the bottom and cohesionless soil (filling) at the top, taking into account a group of plate loading tests conducted in the field. The reliability of the model was proven by comparing the numerical analyzes made with the Plaxis and the results of the field experiments. After the model was validated, parametric studies were carried out to determine the effect of some parameters such as foundation diameter, the height of filling, and strength, on load-deformation behavior. In addition, the scale effect in the results of the study was revealed. The results of the analyses are presented as nondimensional bearing capacity ratios to compare the ultimate bearing capacities of layered soils. When the bearing capacity ratios were examined, an increase was noticed in the bearing capacity ratio as the foundation diameter, the height of filling, and the strength increased. For example, with the increase of the internal friction angle, an increase of 3.37 times at bearing capacity ratio was obtained for a thick filling. However, an increase was observed in the scale effect as the height of filling soil and the strength increased with the reduction of the foundation diameter.

Keywords

Layered soils, Filling, Soil improvement, Finite element analysis, Plate loading test

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