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ABSTRACT AN ANALYTICAL STUDY ON THE MINIMUM CONFINEMENT IN SPIRAL COLUMNS &Ouml / zkaya, Cenan M.S., Department of Civil Engineering Supervisor: Prof. Dr. G&uuml / ney &Ouml / zcebe Co-Supervisor: Prof. Dr. Ugur Ersoy July 2005, 135 pages The minimum spiral ratio equation given in the codes is derived by equating the strength at the second peak to the strength at the first peak for spiral columns tested under uniaxial load. In this study, specimen behavior under combined bending and axial load was taken as basis while deriving proposed equations. Analyses were carried out by using a Moment-Curvature program. For normal strength concrete, one regression and one simplified equation giving minimum spiral ratio are proposed. Difference between two equations arises from the number in front of (Ac/Ack). In regression equation, this number is calculated by means of a function. In simplified equation, this number is a constant. For high strength concrete, a different regression equation is proposed which is valid for concrete strengths up to 95 MPa. Simplified equation proposed for normal strength concrete is also proposed for high strength concrete up to concrete strengths of 120 MPa. It was found that / (i) Simplified equation proposed for normal and high strength concrete yielded consistent results in the range of variables studied / (ii) Except some points, regression equations yielded consistent results / (iii) It is recommended to use simplified equation instead of regression and code equations since it yields more consistent results than code and regression equations. Keywords: Confined Concrete, Ductility, Moment-Curvature, Minimum Spiral Volumetric Ratio

This study presents information on the design procedure of seismic base isolation systems. Analysis of the seismic responses of isolated structures, which is oriented to give a clear understanding of the effect of base isolation on the nature of the structure / and discussion of various isolator types are involved in this work. Seismic isolation consists essentially of the installation of mechanisms, which decouple the structure, and its contents, from potentially damaging earthquake induced ground motions. This decoupling is achieved by increasing the horizontal flexibility of the system, together with providing appropriate damping. The isolator increases the natural period of the overall structure and hence decreases its acceleration response to earthquake-generated vibrations. This increase in period,together with damping, can reduce the effect of the earthquakes, so that smaller loads and deformations are imposed on the structure and its components. The key references that are used in this study are the related chapters of FEMA and IBC2000 codes for seismic isolated structures. In this work, these codes are used for the design examples of elastomeric bearings. Furthermore, the internal forces develop in the superstructure during a ground motion is determined / and the different approaches defined by the codes towards the &lsquo / scaling factor&rsquo / concept is compared in this perspective.

The study aims to determine the relationship between the talent mindset (TM) and organisational commitment (OC) of academic heads of departments. There is a vast problem in the higher education sector with regards to retaining academic staff members. In order for higher education institutions to attract and more specifically retain academic talent, one needs to implement a sound talent management model. Before such a model can be implemented with success, the organisation first needs to have a positive talent mindset. The relationship between talent mindset and organisational commitment may provide a means to develop appropriate interventions or strategies in order to enhance the talent mindset by focusing on improving the organisational commitment and vice versa. Two instruments, namely the Talent Mindset Index (TMI) and Organisational Commitment Questionnaire (OCQ), were administered to a sample of 116 heads of departments at a leading university in South Africa, 53 completed questionnaires were obtained. The responses were analysed using correlation analysis and quantitative techniques. Results confirm that the presence of OC is associated with a positive TM. Therefore, the study provides evidence that there is a correlation between OC and the TM of academic heads of departments. Thus, if management utilises existing techniques to increase OC, this should lead to the enhancement of the heads of departments’ TM. The enhanced TM would equip them to implement a talent management model to attract and retain academic staff. / Dissertation MCom University of Pretoria, 2014 / Human Resource Management / unrestricted

In general, tall buildings, some of which are termed as &ldquo / skyscrapers&rdquo / , are among the typical and almost unavoidable features of the metropolitan cities. There is a competititive race of constructing higher and higher buildings since the birth of the infamous Home Insurance Building in Chicago which is still considered to be the pioneer of the modern tall buildings. Recently, an efficient service core design is strongly needed and inquired with the increase in height and capacity of tall buildings. Such needs and demands are primarily due to the circulation volume of occupants since height has an adverse effect on the size and capacity of the service core. This thesis investigates the features of service cores that play an important role in the planning considerations of tall building design, and their effect on architectural, structural and sustainable design. Within this context, a classification of service cores based on their location in architectural design is proposed.

The duration of construction of a project depends on many factors, such as: cost, location, site characteristics, procurement methods, area of construction, footprint of the building and its height, etc. It is very important to be able to predict these durations accurately in order to successfully complete a project on time. Various construction duration estimation tools have been developed to make accurate predictions, as &ldquo / time is money.&rdquo / The main objective of this study was to develop a model that can be used to predict the construction duration of a project in a reliable and practical way. Contractors can thus use a project&#039 / s characteristics, as given in the tender documents, to estimate the actual amount time it would take them to complete the construction works. In this study, factors affecting the duration of a construction project and models for estimating construction durations were investigated. Within this framework, duration estimation models such as / Bromilow&rsquo / s Time-Cost (BTC) Model and Building Cost Information Service (BCIS) Model were used while Simple Linear Regression (SLR) and Multiple Linear Regression (MLR) analyses were conducted on data related to seven case study buildings that are situated at the Middle East Technical University (METU) campus in Ankara. This data was obtained from the Department of Construction and Technical Works (DCTW) at METU. The closeness in estimation of the regression analyses was investigated and finally an MLR model was obtained which was based on two parameters / the area of the building and the area of its fa&ccedil / ade. On the other hand, as opposed to studies reported in literature, the effect of cost on duration was not seen to be significant.

Although performance based assessment procedures are mainly developed for reinforced concrete and steel buildings, URM buildings occupy significant portion of building stock in earthquake prone areas of the world as well as in Turkey. Variability of material properties, non-engineered nature of the construction and difficulties in structural analysis of perforated walls make analysis of URM buildings challenging. Despite sophisticated finite element models satisfy the modeling requirements, extensive experimental data for definition of material behavior and high computational resources are needed. Recently, nonlinear equivalent frame models which are developed assigning lumped plastic hinges to isotropic and homogenous equivalent frame elements are used for nonlinear modeling of URM buildings. The work presented in this thesis is about performance assessment of unreinforced brick masonry buildings in Turkey through nonlinear equivalent frame modeling technique. Reliability of the proposed model is tested with a reversed cyclic experiment conducted on a full scale, two-story URM building at the University of Pavia and a dynamic shake table test on a half scale, two story URM building at the Ismes Laboratory at Bergamo. Good agreement between numerical and experimental results is found. Finally, pushover and nonlinear time history analyses of three unreinforced brick masonry buildings which are damaged in 1995 earthquake of Dinar is conducted using the proposed three dimensional nonlinear equivalent model. After displacement demands of the buildings are determined utilizing Turkish Earthquake Code 2007, performance based assessment of the buildings are done.

This thesis is about behaviour of traditional timber structures under lateral loads in Turkey. The timber-framed houses are the products of cultural heritage of people who live in Anatolia. These structures have performed well in earthquakes throughout the history. As a result, this study intends to present the observations on the seismic behaviours of traditional timber buildings with the help of computer-generated models. In this thesis, the general characteristics of timber are examined, the earthquake problem is briefly introduced, its effects on buildings are discussed, current knowledge on the earthquake performance of traditional Turkish timber buildings is presented, and their seismic behaviours are shown by using SAP2000 to help to better understand their behaviours in an earthquake.

Historical monuments are the most invaluable reflections of our architectural heritage and cultural identity, both of which have significant roles to create a strong link between the past and the present. They should be conserved in their own settings with their original characteristics or with as minimum changes as possible. However, natural or man-made hazards cause a serious risk for the survival of historical monuments. While some of them require to be strengthened only, some should be relocated to a new site since there are no means to save them without transporting. In this study, an innovative methodology is developed in a general sense for transporting historical masonry monuments without destructing their unity. In the proposed methodology, which is applicable especially to the slender historical structures, it is aimed to transport the structure by tilting it up to a horizontal ground level without dismantling into pieces. Due to the fact that masonry is a very brittle material, externally located prestressed cables are used to strengthen the structure against tension forces, which occur at the time of tilting. Hasankeyf, which is the cradle of various civilizations, is an impressive medieval city located in Mesopotamia region in Turkey. Unfortunately, this unique heritage will be flooded by the reservoir of Ilisu Dam unless the project is cancelled. Therefore, a masonry minaret located in Hasankeyf is selected as a case for this study. Because of the non-homogeneous characteristics of the structural material, Finite Element Method, as a powerful analytical modeling tool, is used in order to evaluate the validity and effectiveness of the proposed methodology. Finally, it is certified that this methodology is successfully applicable for the relocation of historical masonry monuments.

This study is an evaluation on the seismic behavior of the Nahrain Dam, which is located in Khorasan province in the central part of Iran. The finite element method is used for the dynamic analysis of the dam. Using a slope stability computer program, the critical slip surface near the crest of the dam and the yield acceleration corresponding to this slip surface are determined. Static analysis was completed by using the finite element computer program SAP90 and SAP2000 in order to determine the stress conditions within the body of the dam prior to earthquake. The stresses obtained from this analysis were used in the assessment of the dynamic material properties of the dam. Two near by actual earthquakes were modified and used as input motions of different magnitudes. At the next step, the harvested data was used as input data for the program TELDYN to perform dynamic analysis. Permanent displacements under the scenario base motions were calculated by using the Newmark&rsquo / s method.