Due to inadequate lateral stiffness, many reinforced concrete buildings are highly damaged or collapsed in Turkey after the major earthquake. To improve the behavior of such buildings and to prevent them from collapse, repair and/or strengthening of some reinforced concrete elements is required. One of the strengthening techniques is the use of CFRP sheets on the existing hollow brick masonry infill. While using the CFRP sheets their attachment to both structural and non-structural members are provided by CFRP anchor dowels. In this study, by means of the prepared test setup, the pull-out strength capacities of CFRP anchor dowels are measured. The effects of concrete compressive strength, anchorage depth, anchorage diameter, and number of fibers on the tensile strength capacity of CFRP anchor dowel are studied.

Snow indicates the potential stored water volume that is an important source of water supply, which has been the most valuable and indispensable natural resource throughout the history of the world. Euphrates and Tigris, having the biggest dams of Turkey, are the two largest trans-boundary rivers that originate in Turkey and pass throughout the water deficit nations Syria, Iran, Iraq and Saudi Arabia bringing life as well as water all their way. Snowmelt runoff originating from the mountains of Eastern Turkey accounts for 60 to 70 % of total annual discharge observed in Euphrates and Tigris. For an optimum operation of the dams, maximizing energy production, mitigation of floods and satisfying water rights, hydrological models which can both simulate and forecast the river discharges of Euphrates and Tigris are needed. In this study a hydrological model, snowmelt runoff model (SRM), is used in conjunction with remote sensing and geographic information systems to forecast the river discharges in the headwaters of Euphrates River, Upper Euphrates Basin. NOAA and MODIS satellite images were used to derive the snow covered area (SCA) information required by SRM. Linear reduction methodologies based on accumulated air temperature, with constant or varying gradient, were developed to get the continuous daily SCA values from the discrete daily satellite images. Temperature and precipitation forecasts were gathered from two different numerical weather prediction models, namely European Center for Medium Range Weather Forecasts (ECMWF) and Mesoscale Model Version 5 (MM5) from Turkish State Meteorological Services. These data sets provided t+24 hour forecasts of both temperature and precipitation. Temperature, precipitation and SCA information are fed into SRM. Discharge forecasts obtained from the model outputs are compared with the observed values. The overall performance of the model was seen as promising. Possible reasons of the mismatches between the forecasted and observed values are searched. Experiences gained throughout the study are summarized and recommendations on further forecast studies are mentioned.

With increasing awareness of gains and importance of the strategic use of Information and Communication Technologies (ICT), the implementation rate of ICTs in construction sector is increasing. However, these technologies have not been covered by legal and contractual practices. The industry needs to implement application frameworks and legal re-structuring of the existing related laws and regulations to use ICT in a legal and contractually valid environment. In this thesis, an EU funded project, eLEGAL / which defines a framework for legal conditions and contracts regarding the use of ICT in construction industry, is selected as a model project to address legal and contractual issues regarding ICT use in Turkish construction industry. Moreover, the applicability of this project&rsquo / s results are discussed by using real cases and defining the barriers, opportunities, methods and tools to use ICT legally admissible in Turkish construction industry.

Snowmelt runoff in the mountainous eastern part of Turkey is of great importance as it constitutes 60-70% in volume of the total yearly runoff during spring and early summer months. Therefore, forecasting the amount and timing of snowmelt runoff especially in the Euphrates Basin, where large dams are located, is an important task in order to use the water resources of the country in an optimum manner. The HBV model, being one of the well-known conceptual hydrological models used more than 45 countries over the world, is applied for the first time in Turkey to a small basin of 242 km2 on the headwaters of Euphrates River for 2002-2004 water years. The input data are provided from the automatic snow-meteorological stations installed at various locations and altitudes in Upper Euphrates Basin operating in real-time. Since ground based observations can only represent a small part of the region of interest, spatially and temporally distributed snow cover data are acquired through the use of MODIS optical satellite. Automatic model parameter estimation methods, GML and SCE_UA, are utilized to calibrate the HBV model parameters with a multi-objective criteria using runoff as well as snow covered area to ensure the internal validity of the model and to generate a Pareto front. Model simulations show that the choice of study years and timing of satellite images affect the results and further suggest that more study catchments and years should be included to achieve more comprehensible conclusions. In the second part of the study, the calibrated HBV model is applied to forecast runoff with a 1-day lead time using gridded input data from numerical weather prediction models of ECMWF and MM5 for the 2004 snowmelt period. Promising results indicate the possible operational use of runoff forecasting using numerical weather prediction models in order to prevent or at least take precautions before flooding ahead of time.

Contractors have to construct the projects efficiently in accordance with the contract provisions when they accept a contract. All construction projects involve risk and there is no possibility to eliminate all the risks associated with a specific project. Management of risk requires identification and analysis of risk factors. After this risk assessment step, proper response strategies have to be developed so that an optimum risk-reward structure is ensured. Contracts are the grounds where risk allocation schemes between parties are settled and risk-reward mechanisms are defined. Since contractors are usually unable to influence the contract conditions and clauses, they should understand which risks they are retaining under contract conditions. Thus, succesful management of risk requires understanding of contract clauses and identification of secondary risk factors created due to poorly defined contract clauses. The aim of this thesis is to investigate standard conditions of contract, namely FIDIC and GSPW, which are the most widely utilised contracts by the Turkish contractors, from the risk management point of view. For this purpose an interview form is prepared and interviews are conducted using this structured form. Implications of the contract clauses for the risk management strategy of contractors are discussed based on interview findings. The basic philosophy of FIDIC and GSPW are investigated so that necessary suggestions for the contractors can be made considering the risk allocation schemes defined in these documents.

Fiber reinforced polymers (FRPs) have gained popularity in upgrade projects for reinforced concrete structural elements within the last decade because of its ease of application and high strength-to-weight ratio. In the design of an effective retrofitting solution by means of an FRP system, the anchorage capacity has an important role. This study presents the results of an experimental program conducted to determine the strength of carbon fiber reinforced polymers (CFRPs) bonded to concrete prisms or hollow clay tiles that are finished with or without plaster. In the experimental program, different types of anchorage methods were tested in a double shear push-out test setup. A simple and effective strength model is proposed for strip type anchorages based on the existing analytical models and experimental observations from this study. This new model is suitable for determining the design capacity of CFRP-to-concrete and CFRP-to- hollow clay tile joints with or without plaster and accounts for the presence of embedment and concrete strength. Obtained results by using this model were found to closely match with the experimental observations.

The flow characteristics of the subcritical and supercritical flows over a free overfall in a rectangular channel are studied experimentally. A series of experiments were conducted in a tilting flume with a wide range of flow rate. Data collected by several researchers are also included. An empirical relationship, which gives the flow rate as a function of the brink depth, the channel bed slope and the bed roughness are confirmed by using data collected in present study. In addition, the behaviors of the ratio of the brink depth to the critical depth according to several flow parameters are examined. Further, the location of the critical depth in subcritical flows while flow is approaching to the fall is investigated. It is concluded that the location of the critical depth in subcritical flow is a function of the Froude number, channel bed slope and the Manning roughness coefficient. The resemblance or the difference in the occurrence of the profile in sub and supercritical flows examined.

This study concentrates on the modelling of three phase flow and miscible CO2 flooding in pore networks that captures the natural porous medium of a reservoir. That is to say, the network, that is a Matlab code, consists of different sided triangles which are located randomly through the grids. The throats that connect the pores are also created by the model. Hence, the lengths and the radii of the throats are varying. The network used in this research is assumed to be representative of mixed-wet carbonates in 2-D. Mixed wettability arises in real porous media when oil renders surfaces it comes into prolonged contact with oil-wet while water-filled nooks and crannies remain water-wet. The model developed is quasi-static approach to simulate two phase and three phase flows. By this, capillary pressures, relative permeabilities, saturations, flow paths are determined for primary drainage, secondary imbibition, and CO2 injection cases. To calculate the relative permeability, capillary entry pressures are first determined. Then, hydraulic conductances and flow rates of the network for each grid are obtained. Phase areas and saturations are also determined. It is accepted that the displacement mechanism in drainage and CO2 injection is piston-like whereas in imbibition it is either piston-like or snap-off. The results of the model are compared with the experimental data from the literature. Although, the pore size distribution and the contact angle of the model are inconsistent with the experimental data, the agreement of the relative permeabilities is promising. The effect of contact angle in the same network for three phase flow where immiscible CO2 is injected as a third phase at supercritical temperature (32 &deg / C) is investigated. And it is found that, the increase in the intrinsic angles causes decrease in relative permeability values. As another scenario, two phase model is developed in which miscible CO2 &amp / #8211 / water is flooded after the primary drainage of the same 2-D network at supercritical temperature (32 &deg / C). This case is compared with the previous case and the effects of miscibility are investigated such that it causes the relative permeability values to increase. Adsorption is another concern of which its effects are analyzed in a single pore model. The model is compared with the reported experimental data at high temperature and pressures. A reasonable fit is obtained.

ABSTRACT GENERALIZED COUETTE FLOW OF A HERSCHEL - BULKLEY FLUID THROUGH ECCENTRIC ANNULUS - AN APPROXIMATE SOLUTION Seyidoglu, Tijen M.S., Department of Chemical Engineering Supervisor: ismail Tosun Co-Supervisor: Ahmet N. Eraslan January 2006, 134 pages Generalized Couette flow of a Herschel-Bulkley fluid in an eccentric annulus is analyzed by approximating the flow geometry as a slit of variable height. Besides an imposed pressure gradient, one of the plates is considered non-stationary to take into account the axial and/or angular motion of the inner pipe in an eccentric annulus system. Depending on the magnitude and the direction of the applied pressure gradient with respect to the plate velocity, three separate flow cases are studied in which the velocity reaches its maximum value either within the plug flow region or at the moving boundary. Velocity distributions are obtained for each case by solving the equations of continuity and motion. Volumetric flow rate expressions are obtained by integrating the velocity distribution over the cross-sectional area. At a given pressure gradient, the results indicate an increase in volumetric flow rate with an increase in eccentricity ratio. Criteria for each flow type is developed in terms of a dimensionless parameter &amp / #923 / , which takes into account the ratio of the imposed pressure gradient to the plate velocity. Volumetric flow rate expressions for Newtonian, Bingham and power-law fluids are obtained by considering the limiting values of the fluid index and yield stress. The validity of the equations are checked by considering the slit height to be a constant, i.e., flow between parallel plates. Surge/swab pressure calculations are carried out for Herschel-Bulkley, power-law and Bingham fluids and the results are expressed as a function of eccentricity ratio, radius ratio, fluid index and yield stress. The results indicate that when the fluid index and the eccentricity ratio are fixed, a slight increase in the radius ratio causes a tremendous increase in surge/swab pressure, especially for low values of fluid index. On the other hand, displacement of the inner pipe from a concentric position causes a decrease in swab/surge pressure when other parameters are held constant. Comparison with the literature values reveals the fact that flow in an eccentric annulus can be modeled as flow between a slit of variable height as long as the radius ratio is greater than 0.5 and the eccentricity ratio is less than 0.3. The results for other values of radius ratio and eccentricity ratio can be used as initial guess values in carrying out numerical calculations.

In this study, a numerical model is developed to determine shoreline changes due to wind wave induced longshore sediment transport, by solving sediment continuity equation and taking one line theory as a base, in existence of seawalls, groins, T-groins, offshore breakwaters and beach nourishment projects, whose dimensions and locations may be given arbitrarily. The model computes the transformation of deep water wave characteristics up to the surf zone and eventually gives the result of shoreline changes with user-friendly visual outputs. A method of representative wave input as annual average wave characteristics is presented. Compatibility of the currently developed tool is tested by a case study and it is shown that the results, obtained from the model, are in good agreement qualitatively with field measurements. In the scope of this study, input manner of long term annual wave data into model in miscellaneous ways is also discussed.