A planar single facility location problem, also known as the Fermat&ndash / Weber problem, is to

In assuring the energy supply of Turkey, hydroelectric energy plays one of the most important roles in plans formulated to realize equilibrium between energy production and consumption. Hydroelectric power plants on Murat River, a tributary of Euphrates, is a part of the development plan for energy production. Operation of four dams in cascade on Murat River are simulated by using program package HECResSim. For this purpose, ten scenarios are formulated to utilize the hydraulic potential of Murat River between the elevations of 870 m 1225 m. This study provides detailed financial analyses of scenarios and shows how HEC-ResSim program can be used in formulation of alternative scenarios. Electric energy storage requirement due to the rising demand for peaking power is creating a completely new market value, which is also increasing the attractiveness of pumped storage power plants. The results of the simulation performed in Scenario 10 in which two pumped storage power plants are considered have 15% higher internal rate of return value than the other scenarios with conventional turbines. Results demonstrate the increasing attractiveness of the cascade system with reversible pump turbines.

Within the confines of this study, numerical simulations of time dependent variation of downdrag forces on the diaphragm walls are analyzed for a generic soil site, where consolidation is not completed. As part of the first generic scenario, consolidation of a clayey site due to the application of the embankment is assessed. Then two sets of diaphragm walls, with and without bitumen coating, are analyzed. For comparison purposes, conventional analytical calculation methods (i.e., rigid-plastic and elastic-plastic soil models) are also used, the results of which, establish a good basis of comparison with finite-element based simulation results. Additionaly, the same generic cases are also analyzed during the stages of excavation, when diaphragm walls are laterally loaded. As the concluding remark, on the basis of time dependent stress and displacement responses of bitumen coated and uncoated diaphragm walls, it was observed that negative skin friction is a rather complex time-dependent soil-structure and loading interaction problem. This problem needs to be assessed through methods capable of modeling the complex nature of the interaction. Current analytical methods may significantly over-estimate the amount of negative skin friction applied on the system, hence they are judged to be over-conservative. However, if negative skin friction is accompanied by partial unloading as expected in diaphragm walls or piles used for deep excavations, then they may be subject to adverse combinations of axial load and moment, which may produce critical combinations expressed in interaction diagrams. Neglecting the axial force and moment interaction may produce unconservative results.

When the huge building stock in Turkey is considered, it is practically impossible to carry out detailed structural analyses for all of the buildings. In order to cope with the seismic safety evaluation of a large number of existing buildings, it is necessary to use simplified techniques, which can predict the seismic vulnerability of the existing buildings in a relatively short time. The comprehensive structural data compiled for the 48 different reinforced concrete buildings contain full information on their structural characteristics before and after retrofitting and are used in this study. The first basic goal of the study is to develop a procedure through which the building stock under consideration can be classified as &ldquo / safe&rdquo / or &ldquo / unsafe&rdquo / according to the current Turkish Seismic Code. The classification procedure is based on discriminant analysis. The cross-sectional area of the load-bearing members of a building and its preliminary assessment score are selected as the discriminator variables. The second and ultimate basic goal of the study is to propose a method through which the minimum retrofitting cost for satisfying the provisions of the Turkish Seismic Code can be estimated. A quick and uncostly assessment of retrofitting cost estimates based on the procedure described in this thesis will provide a useful input for decisions concerning whether a seismically &ldquo / unsafe&rdquo / building should be rebuilt or retrofitted. Such a situation will save time, labor and money, when it is used for the evaluation of building stocks involving large number of buildings and also in urban transformation operations.

Extreme rainfall events and consequent floods are being observed more frequently in the Western Black Sea region in Turkey as climate changes. In this study, application of a flood early warning system is intended by using and calibrating a combined model system. A regional-scale hydro-meteorological model system, consisting of Weather Research and Forecasting (WRF) model, NOAH land surface model and fully distributed NOAH-Hydro hydrologic models, is used for simulations of 25 heavy-rainfall and major flooding events observed in the Western Black Sea region between years 2000 and 2011. The performance of WRF model system in simulating precipitation is tested with 3-dimensional variational (3DVAR) data assimilation scheme. WRF-derived precipitation with and without data assimilation and Multi Precipitation Estimates (MPE) are used in NOAH-Hydro model to simulate streamflow for flood events. Statistical precipitation analyses show that WRF model with 3DVAR improved precipitation up to 12% with respect to no-assimilation. MPE algorithm generally underestimates rainfall and it also showed lower performance than WRF model with and without data assimilation. Depending on reliability of precipitation inputs, NOAH-Hydro model produces reasonable flood hydrographs both in structure and volume. After model calibration is performed using assimilated precipitation inputs in Bartin Basin, NOAH-Hydro model reduced the average error in streamflow by 23.24% and 53.57% with calibration for testing events. With calibrated parameters, NOAH-Hydro model forced by WRF non-assimilated precipitation input also reduced the error in streamflow but with lower rates (16.67% and 40.72%). With a proper model calibration and reliable precipitation inputs, hydrologic modeling system is capable of simulating flood events.

Fiber reinforced polymers (FRPs) have gained increasing popularity in upgrades of reinforced structural elements due to high strength to weight ratio and ease of application. In this study, the effectiveness of the carbon reinforced polymer wrapping (CFRP) on ductility and strength of circular reinforced concrete columns, made of low strength concrete, is presented. Four circular reinforced columns with similar dimensions, longitudinal and confining steel reinforcement were tested under combined axial load and bending moment. Three specimens were strengthened with CFRP and the results were compared with the control specimen. The main parameter of the experimental study was selected as the level of eccentricity. First of all, the strain profiles of FRPs in the circumferential direction were observed and the confining stress distributions were examined. Then, an axial stress-strain model for FRP confined concrete with a transition from softening to hardening response for different confinement ratios is proposed. The proposed model was verified by comparing the model estimations with the test results obtained from this study and results reported by other researches. In addition, a parametric study was presented to obtain a simple equation to estimate curvature ductility of FRP confined circular columns.

In this study, Yuvacik Basin, which is located in southeastern part of Marmara Region of T&uuml / rkiye, is selected as the application basin and hydrologic modeling studies are performed for the basin. Basin is divided into three subbasins such as: Kirazdere, Kazandere, and Serindere and each subbasin is modeled with its own parameters. In subbasin and stream network delineation HEC-GeoHMS software is used and for the hydrologic modeling studies the new version of HEC-HMS hydrologic modeling software released in April 2006 is used. Modeling studies consist of four items: event-based hourly simulations, snow period daily simulations, daily runoff forecast using numerical weather prediction data, and runoff scenarios using intensity-duration-frequency curves. As a result of modeling studies, infiltration loss and baseflow parameters of each subbasin are calibrated with both hourly and daily simulations. Hourly parameters are used in spring, summer and fall seasons / daily parameters are used in late fall, winter and early spring (snowfall and snowmelt period) to predict runoff. Observed runoffs are compared with the forecasted runoffs that are obtained using MM5 grid data (precipitation and temperature) in the model. Goodness-of-fit between forecasted and observed runoffs is promising. Hence, the model can be used in real time runoff forecast studies. At last, runoffs that correspond to different return periods and probable maximum precipitation are predicted using intensity-duration-frequency data as input and frequency storm method of HEC-HMS. These runoffs can be used for flood control and flood damage estimation studies.

The objective of this thesis is to reveal the perception of the Turkish contractors toward ISO 9001 Quality, ISO 14001 Environmental and OHSAS 18001 Occupational Health and Safety Management Systems using questionnaires. All of the companies participating in the survey have already been ISO 9000 certified. Thus, the questionnaire prepared included more details for the Quality Management System. The results of the questionnaire outcomes are statistically analysed. Analysis of the survey results show that the most common motivators of Management Systems for Turkish contractors are to qualify to tender for local and international projects and to increase competitiveness in overseas markets, however the vision approach of top management is not less important than the financial issues. Most of the companies stated that they implement Management Systems as a part of their improvement strategy as well. This proves that the companies are aware of the benefits of certification in the long term period. Although the most expected advantages of the systems are qualification to tender for projects both locally and internationally, as well as gaining competitive advantage, it has been observed that other benefits are realizedby the Turkish contractors such as / more systematic record keeping, higher company prestige, increased client satisfaction. The major disadvantages realized by practicing the Management Systems are increased documentation and workload. The solution is proposed as to set an internal network and to integrate the systems to reduce paperwork. In conclusion, all of the Management Systems were believed to be as useful tools and Turkish contractors think that their advantages overcome disadvantages.

The aim of this study is to develop a search tool for roads for mobile GIS application. The satellite image of Ankara is the base map of program. There is also a search option for the roads. The application is based on open source libraries, which are ECW for imagery and SQLite for the database of vector. The application is coded in Embedded Visual C++. The study shows that mobile GIS applications can be prepared by the help of open source libraries. There is no need to buy a commercial product to mobilize the GIS.

In this study, semi-distributed hydrological model studies were carried out with the Mike11 model in Yuvacik dam Basin. The basin with a drainage area of 257.8 km2 is located in 12 km South East of Izmit city in T&uuml / rkiye. The basin is divided into three sub-basins named as Kirazdere, Kazandere and Serindere where each sub-basin is represented by its own characteristics. The largest peaks of inflow were observed when the storm events occur due to both snowmelt and rain. Therefore, observed flows for the period of 2001-2006 were grouped as daily and hourly storm events according to the event types such as rainfall, snowmelt or mixed events. Rainfall- Runoff Model (NAM) module of the model was used for the simulation of daily snowmelt and rain on snow events and Unit Hydrograph Method (UHM) module was used for the simulation of hourly rainfall events. A new methodology is suggested for the determination of Curve Number (CN) of the sub-basins by using the fractional area and topographic index values combined with hourly model simulations. The resulting CN values were used in the UHM module v and the suggested CN approach has been validated with the classical SCS-CN approach with GIS analysis. As a result of the study, the parameters of each sub-basin are calibrated with hourly and daily model simulations. The resulting flows are compared with the observed flows where model efficiency is tested with visual and statistical evaluations. The modeling studies give promising results for the computation of runoff during different seasons of a year.