Ph.D. Tezi Görüntüleme

Student: Erol ŞADOĞLU
Supervisor: Prof. Dr. Bayram Ali UZUNER
Department: İnşaat Mühendisliği
Institution: Graduate School of Natural and Applied Sciences
University: Karadeniz Technical University, Turkey
Level: Ph.D.
Acceptance Date: 25/6/2009
Number of Pages: 130
Registration Number: Di697

      Foundations are the elements that transfer the loads acting on them to the soil medium safely and economically. Safety condition expresses satisfaction of bearing capacity and settlement criteria at the same time. Geosynthetics are used frequently to increase bearing capacity of soil medium and to reduce settlement. Footings are also subjected to moments under the effect of lateral loads acting on structures, thus they are loaded eccentrically. Although many studies have been done about centrally loaded footing on reinforced soil, studies about eccentrically loaded footings on reinforced soil are few.

In this study, the ultimate loads and load-settlement behaviors of the eccentrically loaded model shallow strip footing on reinforced sand were investigated experimentally. The internal dimensions of the tank used in the experimental study were 0.9 m x 0.1 m x 0.65 m and the width of the model strip footing was 80 mm. The relative density (Dr) of the sand used in the tests was 74% (dense). The model strip footing (Df=20 mm, Df/B=0.25) on reinforced or unreinforced soil was loaded centrally (e=0) and with various eccentricities (in the kern, e=1/12; on the kern, e=1/6; outside of the kern, e=1/3) in the tests. A wowen geotextile strip (900 mm x 100 mm) was placed horizontally at a depth measuring half of the width of the footing from the footing base in the reinforced tests. Each test was repeated twice to ensure reliability of the results. Plane strain conditions were largely provided for strip footing.

      From the test results, the usage of reinforcement caused an increase in ultimate loads compared with unreinforced tests. The increase varies between 26% - 59% depending on eccentricity and, decreases with increasing eccentricity. The decreases in ultimate loads with increasing eccentricities in the reinforced tests are generally in agreement with customary analysis. The reinforced tests gave larger loads than the unreinforced tests for a settlement value at the same eccentricity. In other words, reinforcement not only increases ultimate loads but also improves load-settlement behavior. The vertical displacements at failure decrease with increasing eccentricities either in the unreinforced or in the reinforced tests. In general, Vertical displacements at failure are larger in reinforced cases.

      Key Word: Reinforced Soil, Bearing Capacity, Eccentrically Loaded Strip Footing