Talha Sarıcı

This study evaluates the economic and carbon footprint impact of using calcium lignosulfonate (CLS) in stabilizing highway subgrade on road pavement. Specifically, the effect of stabilized soil strength on layer thickness, costs, and carbon emissions during the initial construction phase was investigated. Two different soil types (clayey and sandy) were used with varying CLS concentrations. Furthermore, the performance of CLS was evaluated using sodium hydroxide-based alkaline activation (AAS). Standard proctor, unconfined compressive strength (UCS), and California bearing ratio tests were applied to the prepared samples. The experimental results showed that CLS significantly increased the CBR and UCS values of the soil samples. Additionally, it was calculated that the initial construction costs of flexible and rigid road pavements designed on stabilized clayey soil decreased by 14.34% and 25.24%, respectively, while on sandy soils, the decreases were 8.10% and 14.95%, respectively. Meanwhile, it has been determined that CO₂ emissions were reduced by up to 10.76% in flexible pavement designs and by up to 17.88% in rigid pavement designs. Consequently, these findings show that the use of CLS in soil stabilization enables both a reduction in the layer thickness of road pavement designs and a reduction in environmental impacts.

Masonry buildings constitute a significant portion of the building stock in settlements situated along the East Anatolian Fault. Seismic risk is quite high in this region. This study investigates the earthquake response and retrofitting design of a residential masonry that damaged in the 2023 Kahramanmaraş earthquakes. Within the scope of the study, the existing damage condition and material properties of the structure were first determined. Using the collected data, the current state of the structure was analyzed with nonlinear dynamic analyses. Subsequently, potential damage zones were retrofitted using an innovative reinforcement method taken from the literature, and the results were compared. The retrofitting intervention reduced maximum displacement demand by approximately 33.3%, crack width by 26.5%, and inter-story drift ratio by nearly 54.8%. By combining field damage observations with nonlinear time-history analyses and implementing a validated steel-stirrup strengthening scheme, this study provides a practical and transferable methodology for improving the seismic performance of earthquake-damaged masonry buildings in high-risk regions.

This study presents a full-scale field investigation examining the performance of roads on soft clay soil. The main novelty of the study is the comparison of rockfill-stabilized base layers with geosynthetic (including geocell and geogrid with geotextiles) reinforced bases under real traffic loads. Repeated vehicle loads were conducted by a truck that drove over the road sections 5000 times. After every 1000 passes, surface deformations were measured at various points within each section, thus the rutting values were determined. Besides, the coefficient of subgrade reactions (ks) for the sections was calculated based on the results from the plate loading tests to interpret behavior at low surface deformation values. The findings were analyzed alongside the improvement factor derived from the ks value, as well as the traffic benefit ratio and the percentage reduction in settlement calculated from the observed surface deformations of the road to interpret behavior at higher surface deformation levels. The results showed that both rockfill and geosynthetics reduced rutting behavior on the road surface and increased durability. However, it also revealed that geosynthetics controlled rutting more effectively in the long term, while rockfill, although showing strong performance in early deformations, could lose effectiveness at high traffic levels.

Developing technology diversifies and improves the applications of geotechnical engineering as well as all other engineering fields. In the context of this study, an experimental program was conducted to investigate the effect of geotextile, which has been used in remediation works for a long time, and the recently increasingly popular geopolymer coated geotextile elements on the behavior of cohesionless and cohesive soil underloads. Firstly, the optimum geotextile embedment depth for cohesionless and cohesive soil was investigated. Then, geotextile elements coated with geopolymers with different mixture ratios were placed at the optimum depth and were subjected to load with vertical loading tests. Load-displacement curves of the experiments were generated; failure load values were obtained and compared. When the results of experimental studies were evaluated, it was observed that uncoated geotextile and coated geotextile components improved the behavior of both cohesive and non-cohesive weak soil underloads. The obtained increases reached up to 279% compared to the weak soils, however, amounts of increase were variable for both soils. It was predicted that the results obtained from the study can provide inspiration and guidance for the further usage of geopolymer coating applications in field and literature studies.

During disaster management processes, the long- and short-term impacts of the post-disaster period must be carefully examined. The recycling or disposal of waste generated after destructive disasters such as earthquakes is of vital importance for local authorities. In this context, integrating waste recycling into soil improvement methods has become a priority in the process of making geotechnically unsuitable soils suitable for construction. Within the scope of this study, the effect of waste ceramics and bricks obtained from demolished buildings on the behavior of cohesive soil under load was investigated using model loading tests by constructing stone columns within cohesive soil. Then, in order to recycle, waste vehicle tires, model tires created using 3D printing technology were used as encasement for stone columns, and model loading tests were performed. Comparisons were made by calculating the bearing capacity ratio and improvement ratio values from the experimental results. When the results obtained in the study were evaluated, it was observed that the bearing capacity of cohesive soil with waste aggregate could be improved up to 2 times, and this effect could reach up to 3.37 times with tire encasement. In this context, it is believed that the usage of waste aggregates and waste tires can contribute to the waste recycling process both environmentally and economically, and that it may find more applications in field practices.

Yaşanan depremler ve depremler sonrasında ortaya çıkan atık miktarları ve potansiyel zararları değerlendirildiğinde, inşaat yıkıntı atıklarının bertaraf edilmesi/dönüştürülmesi hayati önem taşımaktadır. Bu çalışma kapsamında kohezyonsuz zayıf zeminin statik yükler altındaki performansını arttırmak üzere küçük ölçek model yükleme seti ile, doğal agrega, inşaat yıkıntı atığı ve asfalt atığı ile oluşturulmuş taş kolonlar kullanılarak deneysel çalışmalar gerçekleştirilmiştir. Ayrıca taş kolonların performansını arttırmak üzere üç boyutlu baskı teknolojisi kullanılarak üretilen model araç lastikleri kullanılmıştır. Farklı türdeki iyileştirmeler için göçme yükü değerleri hesaplanmış ve elde edilen veriler karşılaştırılmıştır. Çalışma kapsamında elde edilen sonuçlar değerlendirildiğinde, taş kolon kullanımı ile kohezyonsuz zayıf zeminin taşıma kapasitesinin yaklaşık 3 kat arttırılabildiği görülmüştür. Ayrıca taş kolonların üretilen model lastikler içerisinde inşa edilmesi sonrasında taş kolonların taşıma kapasitesinin yaklaşık 4 kat arttırılabildiği gözlemlenmiştir. İnşaat yıkıntı atığı ve asfalt atığı ile de kohezyonsuz zeminin yük altındaki davranışının önemli ölçüde iyileştirilebilmesi sayesinde çalışma kapsamında elde edilen sonuçların deprem yaşamış bölgeler için oldukça önemli olduğu düşünülmektedir.

Turkey, located on one of the world’s most active fault lines, frequently experiences major earthquakes. The 2023 Kahramanmaraş earthquakes (Mw 7.6 and 7.7) caused significant destruction and housing shortages. Post-disaster shelters are often provided using containers, which require flat and solid ground. This typically involves pouring concrete foundations, but high demand for materials and labor hinders rapid installation. This study investigates screw piles as an alternative foundation system for container settlements. Screw piles can eliminate the need for concrete, offering a faster, cost-effective, and environmentally friendly solution. Finite element analyses using Abaqus were conducted to assess the structural behavior of container foundations with screw piles under real earthquake records. Additionally, a decision-making analysis based on the Analytic Hierarchy Process compares screw piles and concrete foundations in terms of cost, time, sustainability, and safety. Results show that screw piles reduce structural responses and are a more feasible post-disaster foundation solution.

The purpose of this research is to determine the freeze–thaw performance of subgrade soils when stabilized using recycled glass powder (CT). Ensuring the durability of pavement foundations under varying climatic conditions is a key engineering requirement, especially for highways in cold regions. Sandy and clayey soils with different CT contents were prepared, and both untreated and stabilized specimens were subjected to Standard Proctor and unconfined compressive strength (UCS) tests after 7 days of curing. Results showed that CT addition improved strength, with optimum values at 9% CT for clayey soil and 12% CT for sandy soil. Freeze–thaw resistance was assessed by subjecting untreated and optimum CT-stabilized specimens to 3, 6, and 12 cycles, each consisting of freezing at –23°C for 24 hours and thawing at 23 ± 2°C for 23 hours. The 7-day UCS values (0 cycle) were used as references. The results showed that the strength increased by 1.82 times in clay soil samples containing 9% CT and by 1.37 times in sandy soil samples containing 12% CT. It was determined that the highest strength and weight loss occurred at the end of 12cycles. The losses decreased to 78.90% and 1.36% with 12% CT addition, and to 60.64% and 0.78% with 9% CT addition, respectively. The use of CT enhanced both the compressive strength and freeze–thaw resistance of the soils; recycled glass powder can be considered an effective stabilization material, especially for areas exposed to freeze–thaw effects.