Cities in Turkey are great risk pools. Underqualified building stocks are the major components of such risk pools. For the mitigation of risks, &#039 / engineering approach offers retrofitting of individual buildings as an ultimate method. However, this proposition has economic and legal difficulties. Instead, it is essential to develop new policies to focus on areas of high earthquake risk as comprehensive urban regeneration activities. This new policy requires new tools to monitor urban regeneration processes. It is obligatory to make comprehensive plans for high risk areas and to take low income groups into consideration in mitigation action plans. Comprehensive regeneration in existing districts could provide means and standards of safety not necessarily maintained by the retrofitting of individual buildings. Potentials of regeneration processes are readily observed and practiced in Turkey as means of regulating urban regeneration processes, even if for purposes other than safety. Analysis of a set of regeneration projects selected from world experience indicates that current regeneration practice in Turkey is far from a comprehensive approach. Municipalities are fully empowered to designate regeneration areas and carry out redevelopment activities often providing increased dentsities on compensate for the costs. This has been reinstated in the new draft law. Rather than a separate law, general regulation of regeneration could be accommodated in the Development Law 3194. A special Law concerning regeneration could instead focus only on risk reduction issues in cities throughout Turkey. The identification of priorities for such regeneration processes could be made by the Ministry of Public Works and Settlement as the central authority, clarifying the scale and timing of each project. The implementation tools of urban regeneration and issues like authorization, responsibility, funding, and auditing could be determined in this special law. A new approach for urban regeneration is needed to describe organizational, participatory, financial framework.

An analytical study was performed to evaluate the effect of shear wall ratio on the dynamic behavior of mid-rise reinforced concrete structures. The primary aim of this study is to examine the influence of shear wall area to floor area ratio on the dynamic performance of a building. Besides, the effect of shear wall configuration and area of existing columns on the seismic performance of the buildings were also investigated. For this purpose, twenty four mid-rise building models that have five and eight stories and shear wall ratios ranging between 0.51 and 2.17 percent in both directions were generated. These building models were examined by carrying out nonlinear time-history analyses using PERFORM 3D. The analytical model used in this study was verified by comparing the analytical results with the experimental results of a full-scale seven-story reinforced concrete shear wall building that was tested for U.S.-Japan Cooperative Research Program in 1981. In the analyses, seven different ground motion time histories were used and obtained data was averaged and utilized in the evaluation of the seismic performance. Main parameters affecting the overall performance were taken as roof and interstory drifts, their distribution throughout the structure and the base shear characteristics. The analytical results indicated that at least 1.0 percent shear wall ratio should be provided in the design of mid-rise buildings, in order to control observed drift. In addition / when the shear wall ratio increased beyond 1.5 percent, it was observed that the improvement of the seismic performance is not as significant.

Assessment of potential ground motions in seismically active regions is essential for purposes of seismic design and analysis. Peak ground motion intensity values and frequency content of seismic excitations are required for reliable seismic design, analysis and retrofitting of structures. In regions of sparse or no strong ground motion records, ground motion simulations provide physics-based synthetic records. These simulations provide not only the earthquake engineering parameters but also give insight into the mechanisms of the earthquakes. This thesis presents strong ground motion simulations in three regions of intense seismic activity. Stochastic finite-fault simulation methodology with a dynamic corner frequency approach is applied to three case studies performed in D&uuml / zce, L&rsquo / Aquila and Erzincan regions. In D&uuml / zce study, regional seismic source, propagation and site parameters are determined through validation of the simulations against the records. In L&rsquo / Aquila case study, in addition to study of the regional parameters, the limitations of the method in terms of simulating the directivity effects are also investigated. In Erzincan case study, where there are very few records, the optimum model parameters are determined using a large set of simulations with an error-minimization scheme. Later, a parametric sensitivity study is performed to observe the variations in simulation results to small perturbations in input parameters. Results of this study confirm that stochastic finite-fault simulation method is an effective technique for generating realistic physics-based synthetic records of large earthquakes in near field regions.

Efficiency of probabilistic seismic hazard analysis mainly depends on the individual successes of its complementing components / such as source characterization and ground motion intensity prediction. This study contributes to major components of the seismic hazard workflow including magnitude &ndash / rupture dimension scaling relationships, and ground motion intensity prediction. The study includes revised independent models for predicting rupture dimensions in shallow crustal zones, accompanied by proposals for geometrically compatible rupture area-length-width models which satisfy the rectangular rupture geometry assumption. Second main part of the study focuses on developing a new ground motion prediction model using data from Turkish strong ground motion database. The series of efforts include, i) compilation and processing of a strong motion dataset, ii) quantifying parameter uncertainties of predictive parameters such as magnitude and source to site distance / and predicted accelerations due to uncertainty in site conditions and response, as well as uncertainty due to random orientation of the sensor, iii) developing a ground response model as a continuous function of peak ground acceleration and shear wave velocity, and finally, iv) removing bias in predictions due to uneven sampling of the dataset. Auxiliary components of the study include a systematic approach to source characterization problem, with products ranging from description of systematically idealized and documented seismogenic faults in Anatolia, to delineation, magnitude-recurrence parameterization, and selection of maximum magnitude earthquakes. Last stage of the study covers the development of a custom computer code for probabilistic seismic hazard assessment which meets the demands of modern state of practice.

Future seismic losses including the physical, economic and social ones as well as casualties concern a wide range of authorities varying from geophysical and earthquake engineers, physical and economic planners to insurance companies. As its many components involve inherent uncertainties, a probabilistic approach is required to estimate seismic losses. This study aims to propose a probabilistic method for estimating seismic losses, and to predict the potential seismic loss for the residential buildings for a selected district in Bursa, which is a highly industrialized city in Northwestern Turkey. To verify the methodology against a past large event, loss estimations are initially performed for a district in D&uuml / zce, and the method is calibrated with loss data from the 12 November 1999 D&uuml / zce Earthquake. The main components of the proposed loss model are seismic hazard, building vulnerability functions and loss as a function of damage states of buildings. To quantify the regional hazard, a probabilistic seismic hazard assessment approach is adopted. For different types of building structures, probability of exceeding predefined damage states for a given hazard level is determined using appropriate fragility curve sets. The casualty model for a given damage level considers the occupancy type, population of the building, occupancy at the time of earthquake occurrence, number of trapped occupants in the collapse, injury distribution at collapse and mortality post collapse. Economic loss is calculated by multiplying mean damage ratio with the total cost of initial construction. The proposed loss model combines these input components within a conditional probability approach. The results are expressed in terms of expected loss and losses caused by events with different return periods.

The aim of this study is to evaluate the seismic resistance of traditional Ottoman timber frame &ldquo / himis&rdquo / structures, which form the major part of Turkey&rsquo / s cultural heritage, from an engineering point of view. On the other hand, the seismic resistance of traditional Ottoman timber frame structures was not evaluated from an engineering perspective. For the aim of seismic resistance evaluation of traditional Ottoman timber frame houses, the TUBITAK (the Scientific and Technological Research Council of Turkey) project numbered 106M499 was carried out. Within this framework, 16 tests were carried out in the Structural Mechanics Laboratory of Middle East Technical University, by means of 8 1-1 scale timber frames of different geometrical configurations and material, carefully selected from traditional houses in Safranbolu, representing Ottoman timber frame &ldquo / himis&rdquo / technique. The frames were tested without and with different infill/covering types, and parameters that directly or indirectly indicate the behavior of a structure under earthquake loading were derived from the results obtained at the end of experimental work. In addition, capacity calculations were carried out for each test, using ATC-40 procedure. The results demonstrated that Ottoman timber frame &ldquo / himis&rdquo / houses are seismically resistant, and yet there are a number of important points that should be obeyed in their construction regarding size of diagonal elements, size and placement of openings, intervals between vertical studs, as well as connection details. It is also seen that certain infill/covering materials/methods are more advantageous than the others / for example, covering techniques results in a higher amount of maximum lateral load that the frame can bear under the same displacement. Infill with masonry blocks results in a larger increase in weight than in load bearing capacity. The conclusions drawn are intended to be used not only in the conservation of such structures but they are also expected to direct modern seismically resistant constructions.

There are many active and passive vibration control techniques to reduce the effect of energy on structures which emerges during an earthquake and reduce the displacement of buildings that is caused by ground acceleration. Main advantage of passive vibration control techniques over active vibration control techniques is / no external power or a sensor is required for passive vibration control devices (PVCDs) and it results in lower installation and maintenance costs. However, PVCDs require a predefined optimum damping ratio and optimum damping distribution along the structure since they are not adaptive to changing ground acceleration values. During the design of the PVCDs numerous factors such as building properties and earthquake characteristics should be considered. Dry friction damper is an example of PVCD and has an extensive usage in many different fields due to its high energy damping capacity with low cost and ease of installation. In this thesis, damping of seismic energy at buildings with dry friction dampers is investigated and a new optimization method is developed in frequency domain by employing Describing Function Method (DFM) which reduces the computational effort compared to the time domain and finite element solutions drastically. The accuracy and verification of the presented method is investigated by comparing the frequency domain results with time marching solutions. Furthermore, damper placement and slip forces on the dampers are optimized for single and multi-story buildings equipped with dry friction dampers by utilizing the developed method.

CFRD (Concrete Faced Rockfill Dam) construction becomes more frequent recently not only because of its secure nature, but also its economical cost where its built up material is feasible to obtain. Although CFRDs are known to be safe compared to other dam types, it is behavior during an earthquake loading still not a well-known aspect since it is mostly constructed in regions of low seismicity until now. Considering this fact, this study

Tsunami concerns have increased in the world after the 2004 Indian Ocean tsunami and the 2011 Tohoku tsunami. Consequently, tsunami models have been developed rapidly in the last few years. One of the advanced tsunami models is the GeoClaw tsunami model introduced by LeVeque (2011). This model is adaptive and consistent. Because of different sources of uncertainties in the model, observations are needed to improve model prediction through a data assimilation framework. Model inputs are earthquake parameters and topography. This thesis introduces a real-time tsunami forecasting method that combines tsunami model with observations using a hybrid ensemble Kalman filter and ensemble Kalman smoother. The filter is used for state prediction while the smoother operates smoothing to estimate the earthquake parameters. This method reduces the error produced by uncertain inputs. In addition, state-parameter EnKF is implemented to estimate earthquake parameters. Although number of observations is small, estimated parameters generates a better tsunami prediction than the model. Methods and results of prediction experiments in the Red Sea are presented and the prospect of developing an operational tsunami prediction system in the Red Sea is discussed.

Στην παρούσα διατριβή παρουσιάζεται μια μέθοδος αντισεισμικού σχεδιασμού μεταλλικών κατασκευών με βάση τη χρήση λόγων ιδιομορφικής ιξώδους απόσβεσης. Η μέθοδος αυτή βρίσκει τη μέγιστη σεισμική απόκριση μιας κατασκευής με φασματική ανάλυση και χρήση των λόγων ιδιομορφικής ιξώδους απόσβεσης αντί του χονδροειδούς συντελεστή συμπεριφοράς. Η βασική ιδέα της μεθόδου είναι η κατασκευή μιας ισοδύναμης γραμμικής πολυβάθμιας κατασκευής η οποία να μπορεί να αναπαράξει τη σεισμική απόκριση μιας πραγματικής μη γραμμικής. Συγκεκριμένα, αυτή η ισοδύναμη γραμμική κατασκευή έχει την ίδια μάζα και αρχική δυσκαμψία με την πραγματική μη γραμμική κατασκευή και λόγους ιδιομορφικής ιξώδους απόσβεσης οι οποίοι ποσοτικοποιούν το έργο όλων των μη γραμμικών παραμορφώσεων. Αυτοί οι λόγοι ισοδύναμης ιξώδους απόσβεσης για τις πρώτες σημαντικές ιδιομορφές υπολογίζονται συναρτήσει της παραμόρφωσης και της βλάβης της κατασκευής αρχικά σχηματίζοντας επαναληπτικά μια συνάρτηση μεταφοράς στο πεδίο των συχνοτήτων, μέχρις ότου αυτή να ικανοποιήσει συγκεκριμένα κριτήρια ομαλότητας, και μετά επιλύοντας ένα σύστημα μη γραμμικών αλγεβρικών εξισώσεων. Αφού κατασκευαστούν εξισώσεις σχεδιασμού που παρέχουν τους λόγους ιδιομορφικής ιξώδους απόσβεσης, γίνεται χρήση φασμάτων σχεδιασμού τροποποιημένων για μεγάλη απόσβεση και ιδιομορφικής σύνθεσης για τον υπολογισμό των σεισμικών δυνάμεων σχεδιασμού. Μέσω των ελαστικών φασμάτων για διάφορες τιμές απόσβεσης υπολογίζεται ο ιδιομορφικός συντελεστής συμπεριφοράς ο οποίος επίσης δίνεται για τις πρώτες σημαντικές ιδιομορφές συναρτήσει της παραμόρφωσης και της βλάβης της κατασκευής. Τέλος, πραγματοποιείται ο αντισεισμικός σχεδιασμός μιας μεταλλικής πλαισιωτής κατασκευής με ελαστική φασματική ανάλυση τόσο με βάση τους λόγους της ισοδύναμης ιξώδους ιδιομορφικής απόσβεσης όσο και με βάση τους ιδιομορφικούς συντελεστές συμπεριφοράς. Και οι δυο τρόποι σχεδιασμού ελέγχονται χρησιμοποιώντας μη γραμμικές ανελαστικές δυναμικές αναλύσεις και συγκρίνονται με την συνηθισμένη μέθοδο των αντισεισμικών κανονισμών η οποία χρησιμοποιεί μια κοινή τιμή του συντελεστή συμπεριφοράς για όλες τις ιδιομορφές. Συμπεραίνεται ότι η προτεινόμενη μέθοδος αντισεισμικού σχεδιασμού οδηγεί σε ορθολογικότερα και ακριβέστερα αποτελέσματα σε σχέση με τη συνηθισμένη μέθοδο. / A rational method for seismic design of plane building frames based on the use of equivalent modal damping ratios is developed. The method determines the maximum seismic structural response through spectrum analysis using rationally obtained equivalent modal damping ratios instead of the crude strength reduction (behavior) factor. This is materialized in the second part of this work. In this first part, all theoretical aspects regarding equivalent modal damping ratios are developed and described in detail. The basic idea is the establishment of an equivalent linear multi-degree-of-freedom (MDOF) structure which can reproduce the seismic response of a MDOF geometrically and materially non – linear structure. More specifically, this equivalent linear structure retains the mass and stiffness of the original non – linear structure and takes into account geometrical non – linearity and inelasticity in the form of equivalent, time – invariant, modal damping ratios. The equivalent damping ratios for the first few significant modes are numerically computed by first iteratively forming a frequency response transfer function until it satisfies some specific smoothness criteria and then by solving a set of non – linear algebraic equations. Moreover, it is shown that these equivalent modal damping ratios can be computed in such a way so as to be deformation and damage dependent, which can lead to a better design in a direct manner. The concept of equivalent modal damping ratios developed is then employed for the seismic design of plane steel moment resisting frames. The goal is the determination of the maximum seismic structural response through spectrum analysis using rationally obtained equivalent modal damping ratios instead of the crude strength reduction factor. Therefore, design equations providing equivalent damping ratios as functions of period and allowable deformation and damage for the first few significant modes are constructed using extensive numerical data coming from a representative number of plane steel moment resisting frames excited by various seismic motions. These equations can be used in conjunction with a design spectrum, appropriately modified for high damping values, and modal synthesis tools to calculate the seismic design forces of the structure. The proposed method is illustrated by performing the seismic design of a steel moment resisting framed structure. It is concluded that unlike the usual code – based approach, which employs a single and crude strength reduction factor value for all modes, the proposed approach works with deformation and damage dependent equivalent modal damping ratios and thus leads to more accurate and deformation and damage controlled results in a direct and more rational way. Moreover, it is shown that by using equivalent modal dampiing one may define modal strength reduction factors. Thus, alternatively, maximum seismic response may be obtained by spectrum analysis and modal strength reduction factors.