The complex interactions between soil and additives such as lignin, glass powder, and rubber tires were investigated using principles of material and soil mechanics. Previous research has mainly focused on individual additives in clay soils. In contrast, this study investigates soil improvement with two different types of waste materials simultaneously. The improvement of soil properties by hybrid waste materials was evaluated using several laboratory tests, including the standard Proctor test, the unconfined compressive strength test, the California Bearing Ratio (CBR) test, and cyclic triaxial tests. The aim of this research is to identify key parameters for the design and construction of road pavements and to demonstrate that improving the subgrade with hybrid waste materials contributes significantly to the sustainability of road construction. The mechanical and physical properties were evaluated in detail to determine the optimal mixtures. The results show that the most effective mixture for the combination of waste glass powder and rubber tires contains 20% glass powder and 3% rubber tires, based on the dry weight of the soil. For the combination of waste glass powder and lignin, the optimum mixture consists of 15% glass powder and 15% lignin, based on the dry weight of the soil. These results provide valuable insights into the sustainable use of waste materials for soil stabilization in road construction projects.

This paper presents the design of geosynthetic reinforced flexible pavements and their modification by incorporating waste materials into bonded and unbonded layers of the pavement structure. The optimal design of flexible pavements was achieved by minimizing the construction cost of the pavement. The incorporation of waste materials into the pavement structure affects the material properties. Therefore, along with the traffic load, the effects of the material properties of the asphalt concrete, base layer, sub-base layer, and subgrade were analyzed in terms of pavement structure costs and CO₂ emissions of materials used in pavement construction. In addition, a comparison was made between pavements with and without geosynthetic reinforcement in terms of design, optimum construction cost, and CO₂ emissions. The use of geosynthetics is even more effective in pavement structures that contain waste materials in an unbound layer, both in terms of cost and CO₂ emissions. The minimum value of the California Bearing Ratio of the subgrade was determined at which the use of geosynthetic reinforcement for pavement structure with and without the inclusion of waste materials is economically and sustainably justified. The use of geosynthetics could result in a 15% reduction in pavement structure cost and a 9% reduction in CO₂ emissions due to the reduced thickness of unbound layers. In addition, reducing the CBR of the unbound layer from 100% to 30% due to the inclusion of waste materials implies a cost increase of up to 13%. While the present study is based on an empirical pavement design method in which pavement thickness is limited by the pavement thickness index, the same minimum thicknesses are obtained in the optimization process regardless of whether the objective function is the minimum construction cost or minimum CO₂ emissions.

Soils are made stronger and more durable by mixing additive materials. In particular, the use of waste provides environmental and economic advantages for this case. Wastes form in large quantities, however, which creates storage problems. To objective of this study is to research the availability of industrial wastes for soil stabilization. An experimental study was conducted on granular soil specimens mixed with industrial wastes such as marble and granite dust, boron waste, and fly ash in different ratios. Each mixture used two waste materials together. Specifically, fly ash was used with three additional waste materials because of its pozzolanic characteristics. The tests performed included freezing-thawing, unconfined compression strength, and California bearing ratio. The results of the study show that the strength of a specimen is dependent on the additive ratio, curing period, and the number of freeze-thaw cycles. Generally, unconfined compressive strength and California bearing ratio increased with additive materials and curing times. After freezing and thawing, unconfined compressive strength (except granite dust) decreased, whereas weight loss increased due to increasing additives and increasing freeze-thaw cycles.

Clay is a widely used material with unique properties that vary depending on water content and applied pressure. In this study, the electromechanical behavior of clay samples from Afyonkarahisar, Turkey, is investigated by examining the relationship between electrical resistivity, water content, and mechanical loading under uniaxial pressure. The samples with a water content of 10%, 20%, and 30% were tested using a uniaxial loading machine in accordance with ASTM D 2216 and the Turkish standard TS 1900-1. The analysis included measurements of stress, deformation, and electrical conductivity of the soil. A comparative assessment of samples with varying water content revealed that at low moisture levels (10%), the specific electrical resistivity initially decreases due to soil compaction and reduced porosity. However, as stress increases further, resistivity rises significantly as microcracks begin to develop, disrupting conductive pathways. In contrast, at higher water contents (20% and 30%), resistivity consistently decreases with increasing stress, while conductivity increases markedly. This indicates that at elevated saturation levels, the presence of water facilitates charge carrier mobility through ionic conduction, resulting in lower resistivity and higher conductivity. Comparisons with previous studies on clays such as bentonite and kaolinite reveal similar qualitative trends, although differences in the rate of resistivity change suggest a distinct mineralogical influence in Afyonkarahisar clay. This study contributes to a deeper understanding of the geotechnical behavior of this regional clay and supports more accurate performance predictions in engineering and construction applications.

Can ve mal kayıplarıyla birlikte ciddi anlamda maddi ve manevi kayıplara neden olan depremlerin, meydana gelen doğal afetlerin önlenmesi ne yazık ki mümkün değildir. Lakin depremlerin meydana getirebileceği hasarı minimum seviyeye indirgemek mümkündür. Deprem esnasında meydana gelen sismik dalgaların meydana getirdiği tekrarlı kayma gerilmeleri altında, boşluk suyu basıncındaki ani artışa bağlı olarak suya doygun siltli, kumlu ve kil oranı az olan zeminlerde, efektif gerilmenin azalması sonucunda zeminin mukavemet kaybına bağlı olarak sıvı gibi davranması neticesinde yapısal hasarlar meydana getirmektedir. Türkiye tektoniğinde çok önemli bir konumda bulunan Afyonkarahisar ili ve çevresinde birçok aktif fay bulunmaktadır. Bu sebeple sıvılaşmaya bağlı olumsuz etkilerinin azaltılabilmesi için, dinamik (tekrarlı) yüklerin etkisi altındaki yerel zeminlerin nasıl bir davranış göstereceğinin araştırılması, sıvılaşma potansiyelinin önceden belirlenmesi büyük önem arz etmektedir. Bu çalışma kapsamında yerel zemin koşullarının sıvılaşmaya etkisini incelemek amacıyla, Anakaya mostrasındaki yer hareketi olarak Türkiye Bina Deprem Yönetmeliği’ne(2018) uygun olarak seçilmiş olan 11 farklı deprem kaydı verisi kullanılarak bir boyutlu (1-B) dinamik analizler yapılmıştır. Bu kapsamda bölgede yapılmış olan 124 farklı sondaj kuyusu verisi değerlendirilerek çalışma bölgesinin yerel zemin özellikleri belirlenmiştir. Arazi ve laboratuvar verileri kullanılarak zemin özelliklerinin dinamik davranışa etkisini incelemek amacıyla DeepSoil v6.1 yazılımı kullanılmıştır. Bir boyutlu doğrusal olmayan analiz yöntemi kullanılarak her sondaj için sıvılaşma analizleri yapılmıştır. TBDY (2018)’e göre sıvılaşma riski olan zeminlerde, zaman tanım alanında bir boyutlu doğrusal olmayan analiz yöntemi tercih edilmiştir. Bu çalışma neticesinde analiz sonuçları ile birlikte elde edilen veriler değerlendirilerek, çalışma bölgesi sıvılaşma risk haritalarının oluşturulması, bölgedeki bulunan mevcut yapılar ile inşa edilmesi planlanan binaların temel zeminlerinin dinamik davranışlarının belirlenmesi hedeflenmiştir. Unfortunately, it is not possible to prevent earthquakes and natural disasters that cause serious material and moral losses along with loss of life and property. However, it is possible to minimize the damage caused by earthquakes. Under the repeated shear stresses caused by the seismic waves that occur during the earthquake, due to the sudden increase in the pore water pressure, the soils with saturated silty, sandy and low clay content cause structural damage as a result of the soil acting like a liquid due to the loss of strength as a result of the decrease in the effective stress. There are many active faults in and around Afyonkarahisar province, which has a very important position in the tectonics of Turkey. For this reason, in order to reduce the negative effects of liquefaction, it is of great importance to investigate the behavior of local soils under the influence of dynamic (repetitive) loads and to determine the liquefaction potential beforehand. Within the scope of this study, one-dimensional (1-D) dynamic analyzes were carried out using 11 different earthquake record data selected in accordance with the Turkish Building Earthquake Code (2018) as the ground motion in the bedrock outcrop in order to examine the effect of local soil conditions on liquefaction. In this context, the local soil characteristics of the study area were determined by evaluating the data of 124 different boreholes made in the region. DeepSoil v6.1 software was used to examine the effect of soil properties on dynamic behavior using field and laboratory data. Liquefaction analyzes were performed for each borehole using a one-dimensional nonlinear analysis method. According to TBDY (2018), a one-dimensional nonlinear analysis method was preferred in the time history for soils with liquefaction risk. As a result of this study, it was aimed to evaluate the data obtained together with the results of the analysis, to create liquefaction risk maps of the study area, to determine the dynamic behavior of the existing structures in the region and the foundation soil of the buildings planned to be built.

Recent destructive earthquakes have clearly demonstrated that damage distribution in many cities developed on thick alluvial deposits is strongly controlled by local soil amplification and site response effects. Soil conditions therefore play a critical role in determining the characteristics of ground motion and the seismic performance of structures during earthquakes. This study presents the first microzonation-oriented site response assessment for the rapidly urbanizing city of Afyonkarahisar, which is characterized by thick alluvial deposits and a shallow groundwater table. A database consisting of 124 boreholes was compiled to characterize the subsurface stratigraphy of the study area. Shear-wave velocity profiles were verified using both SPT-based correlations and MASW measurements to ensure reliable input parameters for dynamic analyses. One-dimensional equivalent linear and nonlinear site response analyses were performed using the DeepSoil program, employing eleven earthquake ground motion records scaled according to the Turkish Building Earthquake Code. The results indicate that for Earthquake Level-1 (EL-1; 2% probability of exceedance in 50 years) ground motions, nonlinear analyses produce lower amplification factors (1.00–1.62), whereas equivalent linear analyses tend to predict higher amplification values, reaching up to 4.52, owing to their simplified treatment of soil nonlinearity. Under Earthquake Level-2 (EL-2; 10% probability of exceedance in 50 years) motions, both methods yield comparable amplification values ranging from 1.18 to 1.72. GIS-based amplification maps reveal significant spatial variability within the study area and identify zones where local soil conditions may substantially increase seismic demand. The findings suggest that nonlinear site response analysis is more appropriate for representing soil behavior under strong ground motions (EL-1), while both approaches provide comparable results for moderate ground motions (EL-2). Comparisons with Eurocode 8 and NEHRP site classifications further confirm the broader applicability of the results. Overall, this study provides a practical framework for reliable site response assessment that supports earthquake-resistant design and microzonation studies in seismically active regions characterized by complex alluvial environments.