In this study, large-scale experiments have been carried out at 5th Regional Research and Development Headquarters Engineering of Highways in order to determine the contribution of the piles in the pile-raft foundation to the bearing capacity. The bearing capacity were determined for only the raft, the raft with single pile and the raft with four pile under static and repetitive loading. In the examinations, sand samples which were taken from a river bed were used. The sand was classified as uniform clean sand (SP) according to standarts.As a result of study following results were obtained. Only raft has reached lowest bearing capacity at different alternatives under static loading. When used single pile and four piles at piled raft foundation systems, the bearing capacity has increased by 1.130 and 2.52 respectively under static loading. As the number of piles increased, it was observed that the settlements at piled raft foundations under the same repetitive loading decrease.

ÖzetBu çalışmada kompaksiyonun önemli parametrelerinden biri olan sıkıştırma enerjisinin farklı oranlarda zemine uygulanması sonucu, zeminin mühendislik özelliklerinden permeabilite ve ön konsolidasyon basıncında (σ ön ) meydana gelen değişiklikler araştırılmıştır. Çalışmada Atatürk Barajı kil çekirdeğinde kullanılan Sam-Tekin ariyet ocağından örselenmiş zemin numuneleri alınmıştır. Killi zemini sınıflamak için kıvam, tane boyu ve özgül ağırlık deneyleri yapılmıştır. Standart Proctor deneyleri yapılarak zeminin farklı kompaksiyon enerjisinde (15, 25, 35, 45 ve 55 vuruşlarda) maksimum kuru birim hacim ağırlıkları ve optimum su içerikleri belirlenmiştir. Belirlenen bu maksimum kuru birim hacim ağırlık ve optimum su içeriği değerlerinde tekrar Standart Proctor deneyleri yapılmış ve konsolidasyon ringlerine numuneler alınarak permeabilite ve konsolidasyon deneyleri yapılmıştır. Sonuç olarak zemine uygulanan kompaksiyon enerjisi arttıkça; zeminin kuru birim hacim ağırlığının arttığı, optimum su içeriğinin azaldığı, ön konsolidasyon basıncının arttığı, boşluk oranın azaldığı ve permeabilitesinin tespit edilmiştir.Anahtar Kelimeler: Kompaksiyon enerjisi, Permeabilite, Efektif gerilme Changes of Permeability and Effective Stress Compacted Clayey Soils Depending on the Compaction Energy AbstractIn this study changes in engineering parameters such as permeability and effective stress due to application of the compaction energy, one of the important parameters of compaction in different proportions have been investigated. Undisturbed clay samples obtained from the Sam-Tekin clay quarry, where the clay core material of the Ataturk Dam was taken, have been used in the study. In order to classify the samples, Atterberg Limits, grain size analysis and spesific gravity tests have been performed. The maximum dry unit weights and optimum moisture contents of compacted samples for 5 different compaction energies (15, 25, 35, 45, 55 blows) have been determined by means of compaction tests. Permeability and consolidation tests have been performed on compaction samples taken from the compacted at the determined dry unit weights and optimum moisture contents. In conclusion, it was determined that as the higher the compaction energy increases, the dry unit weight and preconsolidation pressure increase and the optimum moisture content, void ratio and permeability decrease.