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Öğe Effects of curing time and freeze-thaw cycle on strength of soils with high plasticity stabilized by waste marble powder(Springer, 2020) Aydin, Kemal; Sivrikaya, Osman; Uysal, FirdevsThis paper presents the experimental study on stabilization of fine-grained soils using waste calcitice marble powder (CMP) and dolomitic marble powder (DMP). Unconfined compressive strength (UCS) tests were conducted on both the pure and stabilized soil specimens with the percentages of 5, 10, 20, 30, and 50% waste marble powder (MP) by weight. The soil specimens mixed with two types of waste MP were cured for 7, 30, and 60 days and also subjected to freezing and thawing with 1, 3, 5, 7, and 11 cycles to investigate the effect of curing time and freezing-thawing on unconfined compressive strength (q(u)) and undrained elastic modulus (E-u). Besides, mass losses (ML) of soil specimens were calculated after freezing-thawing cycles. According to the test results, the values of q(u) and E-u of stabilized soil specimens increased sharply at waste MP content of 5% and then decreased with increasing of MP in highly plastic silt (MH) with plasticity index of 21. q(u) and E-u increased with curing time dependent on the waste marble type and content in both soil type of specimens. As a result of this study, the waste MP contributed the fine-grained soils more resistant to freezing-thawing.Öğe Evaluation of the bearing capacity of poor subgrade soils stabilized with waste marble powder according to curing time and freeze-thaw cycles(Springer Science and Business Media Deutschland GmbH, 2021) Yorulmaz, Aysegul; Sivrikaya, Osman; Uysal, FirdevsIn this study, pavement subgrade soils were stabilized with two difference types of waste marble powder, and California bearing ratio (CBR) tests were conducted to evaluate the improvement in their bearing capacity. To this end, highly plastic silt (MH) and highly plastic clay (CH) layers were used as the subgrade soil material. A number of unsoaked CBR tests were conducted on the test samples by adding a varying percentage of calcitic marble powder (CMP) and dolomitic marble powder (DMP) using different freeze-thaw cycles (0, 1, 3, 5, 7, and 11 cycles) and curing times (0, 7, 30, and 60 days) in the laboratory. The waste marble powder ratios were taken as 5, 10, 20, 30, and 50% by the dry weight of each soil specimen. SEM and energy dispersive X-ray (EDAX) analyses were also performed on the specimens to determine the efficiency of the marble powders. According to the comparison based on the CBR values, the inclusion of an appropriate amount and type of waste marble powder positively affected the bearing capacity of the subgrade soil samples regardless of curing time and number of freeze-thaw cycles. Moreover, both curing time and freezing-thawing cycles influenced the CBR values depending on the waste marble powder type and content and subgrade soil type. © 2021, Saudi Society for Geosciences.Öğe Nano parçacık silisyum dioksit (SiO2) ile yüksek fırın cürufu karışımınınkompaksiyon özelliklerine etkisi(2021) Uysal, Firdevs; , VedatBu çalışma, silisyum dioksit (SiO2) nanoparçacıkları ile yüksek fırın cürufu karışımının ince daneli zemin stabilizasyonundaki etkisini araştırmaktadır. Bu çalışmanın ana amacı, SiO2 nanoparçacıkları ve yüksek fırın cürufu kullanarak stabilize edilmiş ince daneli zeminin kompaksiyon özelliklerini (maksimum kuru yoğunluk ve optimum su içeriği) değerlendirmektir. Stabilize edilmiş ince daneli zeminlerin kompaksiyon özelliklerini elde etmek için standart proktor testleri yapılmıştır. Zeminin farklı yüksek fırın cüruf yüzdeleri (%10, %20,%30 ve%40) ve küçük miktarlarda (%1 ve %1.5) SiO2 nanoparçacıkları ile karıştırıldığı iki farklı tip numune hazırlanmıştır. Yüksek fırın cürufunun etkisi ve SiO2 nanoparçacıklarının yüksek fırın cürufu ile karışımının etkisi ayrı ayrı incelenmiştir. Test sonuçları, yüksek fırın cüruf içeriğindeki artışla birlikte maksimum kuru yoğunlukta bir düşüş olduğunu ortaya koymuştur. Ayrıca, zemine yüksek fırın cüruflu ile SiO2nanopartiküllerinin eklenmesi maksimum kuru yoğunluğu arttırmıştır. Elde edilen sonuçlar küçük miktarlardaki SiO2 nanopartiküllerinin genellikle kompaksiyon özelliklerini iyileştirdiğini göstermektedir.Öğe Numerical estimation of the one-dimensional consolidation behavior of clay(University of Maribor, 2020) Uysal, Firdevs; Sivrikaya, OsmanThe consolidation behavior of clayey soils is traditionally evaluated in the laboratory using the one-dimensional consolidometer test. A new oedometer cell design with a ring of 60 mm in height, 75 mm in diameter was made to measure the excess pore-water pressure at the undrained base of the specimen and the friction between the soil and the ring, and to determine the ?-log p curve. This study deals with numerical modeling of the one-dimensional consolidation test and comparing the data obtained from the experimental study with the data from the modeling. In the modeling, the Soft Soil and Soft Soil Creep models were used for the clay proposed in this study. The results show, as a general trend, that the data from the numerical modeling are compatible with those from the experimental study. © 2020 University of Maribor. All rights reserved.Öğe NUMERICAL ESTIMATION OF THE ONE-DIMENSIONAL CONSOLIDATION BEHAVIOR OF CLAY(Univ Maribor, 2020) Uysal, Firdevs; Sivrikaya, OsmanThe consolidation behavior of clayey soils is traditionally evaluated in the laboratory using the one-dimensional consolidometer test. A new oedometer cell design with a ring of 60 mm in height, 75 mm in diameter was made to measure the excess pore-water pressure at the undrained base of the specimen and the friction between the soil and the ring, and to determine the epsilon - log p curve. This study deals with numerical modeling of the one-dimensional consolidation test and comparing the data obtained from the experimental study with the data from the modeling. In the modeling, the Soft Soil and Soft Soil Creep models were used for the clay proposed in this study. The results show, as a general trend, that the data from the numerical modeling are compatible with those from the experimental study.Öğe Prediction of collapse potential of soils using gene expression programming and parametric study(Springer Heidelberg, 2020) Uysal, FirdevsSoil collapse is defined as a considerable reduction in soil volume when inundated under constantly applied pressure is known to be responsible for the failure of geotechnical structures such as highway/railway embankments and earth dams. Gene expression programming (GEP) is used as an artificial intelligence (AI) for the formulations of collapse potential in terms of the difference between the sand and clay percentages or the coefficient of uniformity, initial water content, initial dry unit weight, and wetting pressure in this paper. The experimental data available in the literature have been gathered for predicting collapse potential with the empirical formulations developed in the training and test sets of GEP-based models. Besides, additional experimental data derived from different literature are obtained to confirm the applicability and generalizability of the developed GEP-based formulations. The prediction performances of GEP models are compared to the experimental results and regression-based formulations proposed in the literature. These comparisons and statistical values obtained from analyses show that the GEP-based models are detected to be more effective methods to estimate the collapse potential. Moreover, a series of parametric analysis is conducted to perceive influences of input parameters on collapse potential by using GEP-based formulations.Öğe Taş kolon tasarım parametrelerinin konsolidasyona etkisinin araştırılması(2023) Uysal, Firdevs; Yıldız, AbdulazimTaş kolon, yumuşak zeminin taşıma kapasitesini artırmak, yumuşak zemin konsolidasyonunu hızlandırmak ve zemin oturmasını azaltmak için kullanılan etkili bir zemin iyileştirme yöntemidir. Bu çalışmada, literatürde geçmiş bir laboratuvar çalışmasından alınan doğrulanmış bir sayısal model ve model parametreleri kullanılarak taş kolonun zamana bağlı davranışını değerlendirmek için bir dizi sayısal çalışma yapılmıştır. Taş kolon ile iyileştirilmiş yumuşak zemin birim hücre yaklaşımı kullanılarak Plaxis 2D ile modellenmiştir. Gerilme konsantrasyon oranı, permeabilite oranı ve çap oranının taş kolonun zamana bağlı oturma davranışı üzerindeki etkisini anlamak için parametrik çalışmalar yapılmıştır. Sayısal sonuçlar, bu tasarım parametrelerinin konsolidasyonun hızlanması ve ortalama konsolidasyon hızının artması üzerinde önemli bir etkiye sahip olduğunu göstermektedir.Öğe The Efficiency of Waste Marble Powder in the Stabilization of Fine-Grained Soils in Terms of Volume Changes(Springer Heidelberg, 2020) Sivrikaya, Osman; Uysal, Firdevs; Yorulmaz, Aysegul; Aydin, KemalThe recycling of waste marble powder (MP) for soil stabilization is still under research for geotechnical engineers, with the aim of improving poor soil properties. This paper investigated the effect of calcitic marble powder (CMP) and dolomitic marble powder (DMP) on the geotechnical properties of fine-grained soils. Consistency limits, linear shrinkage, expansion index, and one-dimensional consolidation tests were performed on non-stabilized and stabilized samples with 5, 10, 20, 30, and 50% of waste CMP and DMP to determine the efficiency of using waste marble powders in soil stabilization. The marble powder ratio which gave the best results was determined as 50% for both MH samples and CH samples. The laboratory test results showed that the waste marble powders were effective in soil stabilization by reducing the plasticity index from 49 to 26 for the CH samples and from 21 to 9 for the MH sample, expansion index from 45 to 20 for the CH sample and from 32 to 7 for the MH sample, swelling index from 0.0030 to 0.0012 for the MH sample, compression index from 0.013 to 0.010 for the MH sample, and linear shrinkage from 16.2 to 10.5 for the CH sample. The waste MP content and fine-grained soil type need to be taken into consideration in soil stabilization based on volume change.
