Geogrid Kaplı Taş Kolonların Taşıma Kapasitesi ve Genişleme Davranışı

In recent years, geogrid encasement has been used to extend the utilization of stone columns to improve soft soil’s properties. This paper investigates the influence of geogrid encasement on the performance of stone columns in soft clay deposits. Experimental and numerical studies were conducted to figure out behavior of stone columns with and without geogrid reinforcement. The small scale laboratory tests were carried out. In addition, PLAXIS which is a finite element package intended for the two dimensional analysis of deformation and stability in geotechnical engineering was used to numerical studies. Before conducting the numerical studies, the validation between results of the experimental studies and numerical analysis was performed. After validation, the numerical studies were performed with different parameters such as the rigidity effect of geogrid, depth of geogrid reinforcement and lateral bulging of the stone columns. In addition, group of stone column was investigated. As a result of this studies, load carrying capacity and bulging behavior of the geogrid encased stone column was significantly influenced from the depth and the stiffness of the geogrid.Son yıllarda yumuşak zeminlerin iyileştirilmesi için kullanılan taş kolonun kullanımını artırmak için geogrid kaplama kullanılmaktadır. Bu çalışmada, geogrid kaplamanın, yumuşak zemin yatağı içerisindeki taş kolonun performansına olan etkisi araştırılmıştır. Geogrid kaplı ve geogridsiz taş kolonun davranışını belirlemek için deneysel ve numerik çalışmalar gerçekleştirilmiştir. Deneysel çalışma için küçük ölçekli laboratuvar testleri gerçekleştirilmiştir. Ayrıca, geoteknik mühendisliğinde iki boyutlu deformasyon ve stabilite analizleri için tasarlanmış sonlu elemanlar programı olan PLAXIS numerik çalışmalar için kullanılmıştır. Numerik çalışmalar gerçekleştirilmeden önce deneysel çalışmaların ve numerik analizlerin uyumluluğu kontrol edilmiştir. Uyum elde edildikten sonra taş kolonda geogridin rijitliğinin, geogrid kaplama boyunun ve yanal genişleme gibi farklı parametrelerin etkisi numerik çalışmalar ile araştırılmıştır. Ek olarak grup kolonlar da incelenmiştir. Bu çalışmanın sonuncu olarak, geogridin kaplama boyu ve rijitliği geogrid kaplı taş kolonun yük taşıma kapasitesini ve genişleme davranışını önemli ölçüde etkilemektedir

Filamentary keratopathy caused by corneal occlusion by large-angle paralytic strabismus

Purpose: To report a case of filamentary keratopathy in a patient with large-angle paralytic strabismus

Investigation of retinal nerve fiber layer thickness and ganglion cell layer-inner plexiform layer thickness in patients with optic pathway gliomas

Purpose This study aimed to compare the optical coherence tomography (OCT) findings of optic pathway glioma (OPG) patients (sporadic or secondary to neurofibromatosis type 1, NF1) with NF1 without OPG patients and healthy controls

Gamma-knife-based stereotactic radiosurgery for medium- and large-sized posterior uveal melanoma

This study investigated the use of gamma-knife-based stereotactic radiosurgery (GKRS) for medium- and large-sized posterior uveal melanoma treatment

Evaluation of Rockfill Stabilized-Geosynthetics Reinforced Road Base with Repeated Plate Loading Tests

In this study, the performance of unpaved road sections over soft clay soil geosynthetic-reinforced and stabilized with rock fill layer was evaluated using repeated plate loading tests. A total of 10 field tests were carried out using a circular model rigid plate with a diameter of 0.30 m. The parameters investigated included the location and type of geosynthetics and loading conditions (number of loading cycle and traffic loading condition). Based on the test results, the least deformation was observed in the rockfill section. The geocell placed at a depth of one-third thickness of the granular fill layer from the top showed improved performance and was more effective as compared with other geosynthetic reinforcements. However, for granular fill geosynthetic-reinforced or stabilized with rock fill layer, the results demonstrate an improvement in the rutting performance of the pavement and the definite trend of increasing reloading elastic modulus, depending on the traffic loading situation. It has been also observed that the use of geocell or geogrid reinforcement in granular fill layer or more rigid rockfill layer provides an important increase in the modulus improvement ratio (MIR) by at least 36%, 45% and 60% compared to the granular fill section, respectively

Acquired ptosis secondary to vernal conjunctivitis in young adults

Purpose: To establish a relation between prolonged severe vernal conjunctivitis and upper eyelid ptosis

Long-term results of combined viscotrabeculotomy-trabeculectomy in refractory developmental glaucoma

Background To evaluate the outcomes of combined viscotrabeculotomy-trabeculectomy in patients with refractory developmental glaucoma and to compare the success and complication rates with classical trabeculotomy-trabeculectomy procedure