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The research reported in this paper was financed in part by a grant form the Carnegie Commission on Higher Education. / Bibliography: leaf [14].

&Ccedil / ayirhan soil is a collapsible soil. Collapsible soils are generally unsaturated, low-density soils with high voids between grains where the binding agents are sensitive to saturation. When exposed to water, binding agents break, soften or dissolve such that the soil grains shear against each other and reorient in denser configurations. This reconfiguration causes a net decrease in the soil mass, resulting in large and often unexpected settlements, which can totally destroy roads, underground utilities, and structures and alter surface drainage. Uses of collapsible soils as a natural construction material in fills or embankments also may cause serious stability problems. In this study, an extensive research program was carried out to investigate some geotechnical properties such as compaction, triaxial strength, bearing ratio and permeability of collapsible soil, found in &Ccedil / ayirhan Thermal Power Plant area, by treating with Class C fly ash and desulphogypsum (thermal power plant by-products that are to be handled for environmental reasons) in various proportions. The study has revealed that 20% and 25% fly ash or 5% desulphogypsum treatments (by dry weight of the mixture) improve the strength and bearing characteristics of &Ccedil / ayirhan soil.

This study analyzes the relationship between financial development and income inequality by using panel data of 60 developing and developed countries for the period 2000-2010. We find evidence for the linear negative relationship between financial development and income inequality which asserts that financial development reduces income inequality. We also find evidence supporting Kuznets inverted u-shaped hypothesis on development-income inequality link, except that for the developed countries where we find evidence for u-shaped hypothesis. It is also concluded that the panel is stationary without unit root, indicating that shocks on income inequality is not persistent.

Stone column technique is mostly used to reinforce soft cohesive soils. Settlements are decreased under foundations and bearing capacity is increased. This study initially focuses on a comprehensive review of literature about stone column reinforced soils. Afterwards, numerical modeling of stone column reinforced soft clays is done. Three different cases are chosen on different foundation soils mainly soft clays. Parametric studies are done to determine influence of parameters on settlement reduction ratio under three different foundation conditions. Analyses are converted to two dimensional conditions and this conversion is also compared within the scope of this study. Settlement reduction ratio response to variation in parameters revealed similar results under three different foundation conditions.

In this research, the dynamic behavior of a seismic isolation system composed of high strength geotextile placed over an ultra-high molecular weight polyethylene (UHMWPE) geomembrane (together called as composite liner) beneath the structure is investigated experimentally. The results of the shaking table experiments which were performed on model structures both under harmonic and modified earthquake motions with and without the seismic isolation (composite liner system), are presented in the thesis. The main focus is given on the potential improvement obtained by use of the composite liner system as compared to the unisolated cases. Based on the performed experiments, it is observed that the utilization of composite liner system provides significant reduction in the accelerations and interstorey drift ratios of structures under harmonic motions while signifant drop is obtained in the spectral accelerations under earthquake motions which provide noticeable improvement in the durability of structures under dynamic effects at the expense of increased translational displacements.

ABSTRACT COMPARISON OF ANALYSIS METHODS OF EMBEDDED RETAINING WALLS HARMANDAR, Serkan M.S., Department of Civil Engineering Supervisor : Prof. Dr. Yener &Ouml / zkan Co -Supervisor : Dr. Oguz &Ccedil / aliSan December 2006, 123 pages In this study a single-propped embedded retaining wall supporting a cohesionless soil is investigated by four approaches, namely limit equilibrium, subgrade reaction, pseudo-finite element and finite element methods. Structural forces, such as strut loads, wall shear forces, bending moments are calculated by each method and results are compared. The analyses are carried for for three values of internal friction angle of soil / 30o, 35o, and 40o. Effects of modulus of soil elasticity of the backfill and wall stiffness on structural forces are investigated by using different values for these parameters. It is found that, in those of obtained by, limit equilibrium approach results in embedment depth greater than other methods. Minimum strut loads for the same soil and structure parameters are obtained by limit equilibrium method. An increase of Young&rsquo / s modulus of the soil results in decrease of the strut loads.

In this thesis we examined the export dynamics at the firm level. A two period model is proposed for the life of firms. The firms may have three different behaviors: staying out of markets, producing for the domestic market, and producing for both the domestic and the export markets. During two periods, firms may enter or exit the markets according to their expected) profits. All firms are profit maximizing such that they compare the maximum (expected) profits in the domestic and export markets. Firms are also heterogenous so that they have different levels of productivity. We examined changes in investment, market share and profits with respect to changes in the market and firm parameters. The profits and investments of the exporting and non-exporting firms are compared by both analytical and numerical methods.

In this study, fracture grouting technique of saturated, granular soils of different fine content were investigated. Model tests were carried out by using fluid particulate grouts namely micro fine cement and ordinary portland cement grouts. Basically, relationships were obtained between soil conditions (grain size distribution, relative density, overburden stress) and grouting parameters (type of grout, grouting pressure, amount of injected grout, rheological properties of the grout or water/solids ratio). At the end of the tests the soil specimens were exposed and the final grout shapes were observed and correlated with the grouting parameters. Response of soil specimens to grouting process under different grouting pressures and grout compositions was analyzed. Amount of heave occurred at the top of the specimen during injections was recorded at each test. Micro fine cement grout and ordinary portland cement grout showed significant differences rheologically. Micro fine cement grout, with much higher Blaine fineness, lower specific gravity, lower viscosity and cohesion, lower bleed and filtration coefficients, made it possible to fracture the fine sandy soils of different fine content. Results of tests performed with micro fine cement grouts show that fracturing pressure generally decreases with an increase in the water content of the grout but generally increases as the fine content of the soil increases. A higher relative density of the soil increases the fracturing pressure significantly. The volumes of grout injected into soil specimens until fracturing show an increasing tendency as the water/solids ratio decrease. Ordinary portland cement grout, on the other hand, exposed to high pressure filtration during grouting in relatively clean sand and addition of some amount of kaolinite or fines is required to reduce the filtration percentages during grouting in order to fracture grout the sandy soil. Filtration due to high permeabilities results in accumulation of cement particles around the injection point and grouting tends to take a form similar to compaction grouting.

In this study, bending moment distributions developed in laterally loaded passive pile and passive pile groups in cohesionless soil were investigated in laboratory conditions through model pile experiments. Different from the active pile loading, the lateral load was given directly to the piles using a movable large direct shear box. In these experiments strain gauges fastened to the piles and a computer based data reading system were used. The strain values were measured at five levels on the piles. The behavior of a single pile and a pile group having five piles were investigated through strain measurements in order to observe bending moment distribution on the piles. After evaluating the test results, the behavior of passive single pile was found to be similar to the results obtained in early studies. Negative bending moments were observed at the specified depths above the shear plane and positive bending moments were measured at the level of the shear plane and below the shear plane. Maximum bending moments were obtained at 0.7L (L: Length of Pile) for single piles and piles in the group. Above the shear plane, maximum bending moments within the pile group were found to be developed on the piles nearest to the loading. On the shear plane maximum bending moments were developed on the piles farthest from the loading just like active piles. Below the shear plane, maximum bending moments were developed mainly on the piles nearest to the loading.