Due to the randomness inherent in the occurrence of earthquakes with respect to time, space and magnitude as well as other various sources of uncertainties, seismic hazard assessment should be carried out in a probabilistic manner. Basic steps of probabilistic seismic hazard analysis are the delineation of seismic sources, assessment of the earthquake occurrence characteristics for each seismic source, selection of the appropriate ground motion attenuation relationship and identification of the site characteristics. Seismic sources can be modeled as area and line sources. Also, the seismic activity that can not be related with any major seismic sources can be treated as background source in which the seismicity is assumed to be uniform or spatially smoothed. Exponentially distributed magnitude and characteristic earthquake models are often used to describe the magnitude recurrence relationship. Poisson and renewal models are used to model the occurrence of earthquakes in the time domain. In this study, the sensitivity of seismic hazard results to the models associated with the different assumptions mentioned above is investigated. The effects of different sources of uncertainties involved in probabilistic seismic hazard analysis methodology to the results are investigated for a number of sites with different distances to a single fault. Two case studies are carried out to examine the influence of different assumptions on the final results based on real data as well as to illustrate the implementation of probabilistic seismic hazard analysis methodology for a large region (e.g. a country) and a smaller region (e.g. a province).

The aim of this thesis is to demonstrate that it is possible to design earthquake resistant residential structures without significant compromises in the spatial quality and economic viability of the building. The specific type of structural system that this thesis focuses on is the reinforced concrete skeleton system. The parametric examples and key studies that are used in this research are chosen among applied projects in the city of Bolu. This city is chosen due to its location on the North Anatolian Fault and its destructive seismic history. The structural validity of the hypothesis was demonstrated through an analytical process during which a set of 7 models were tested. 5 of these were designed as idealized parametric models and 2 of them were based on actual buildings destroyed in earthquakes. The architectural validity of the hypothesis was demonstrated on a set of 3 architectural projects. Projects were subjected to a comparative evaluation between their original states and the modified seismically resistant versions. The architectural comparison between earthquake resistant and non-resistant states was made on a planimetric basis. Comparison parameters were: floor area / size, location and number of rooms / and access to view. The feasibility of seismically resistant reinforced concrete residential buildings was demonstrated through an approximate cost analysis which has proven that designing earthquake resistant structures only resulted in an acceptable 4-8 percent rise in the overall building cost.

About half of the total building stock in Turkey is masonry type building. Masonry buildings in Turkey, especially in rural areas, are constructed without any engineering knowledge mostly by their own residents. They generally have heavy roofs. Masonry type buildings also have thick and heavy wall materials. Heavy roof and wall material generate large inertial forces in the case of an earthquake. Brittle failure of walls leads to total failure of whole system followed by sudden collapse of heavy roof. The aim of this thesis is to understand failure mechanisms of brick masonry walls, prevent their brittle failure and allow the walls to dissipate energy during an earthquake. Furthermore, ultimate capacity increase was also targeted by using low cost and easy to obtain material. In order to find an economical and effective way in strengthening of brick masonry walls in their in-plane direction, steel rebars were used as post-tensioning materials in brick masonry walls and house tests. Springy connections were utilized in the reinforcing and post-tensioning bars in order to prevent early loss of post-tension due to wall cracking or rebar yielding. Separate tests were conducted with and without rebars and springs in order to compare their results. v The test results indicated that the ultimate lateral load capacity of 6m long brick masonry house increased up to about 6 times with respect to its nominal value. Energy dissipation also increased up to about 10 times of the original house. Lateral load capacity increase in 2m long rebar post-tensioned brick masonry walls were measured as about 17 times when compared with the original wall. The energy dissipation capacity was also increased about 30 times the nominal value. A general procedure was developed to assess the vulnerability of single storey masonry houses, which calculates the earthquake demand acting on each wall segment. Comparison of capacity versus demand enables evaluation of wall segments and leads strengthening calculations if necessary. Derived formulas were used to calculate post-tensioning force and design vertical and diagonal rebars. The procedure was demonstrated using properties of an existing house and strengthening cost was found to be about 10% of the building cost. The results of the conducted tests have shown that rebar post-tensioning of brick masonry walls is an effective and cost-efficient way of strengthening the walls in their in-plane direction and can be used as an economical and simple technique for seismically vulnerable masonry houses. Spring based connection detail has improved the post cracking performance of the walls at large deformations by keeping the wall reaction higher after ultimate strength has reached as well as increased the energy dissipation capacity of the walls.

Earthquakes in Turkey, among all natural disasters claim the highest losses in terms of human lives, material and economic assets. Most of the lives are lost within the collapsed buildings, and most of the material and economic losses are again directly related to the functional capacities of the building stock. The method of risk assessment in the existing building stock is therefore an essential step in the maintenance of safer urban environments. Analysis of risks in the building stock is usually claimed to demand surveys of engineering studies. Yet risk determination studies by planners could prove not only a more comprehensive approach, but less time consuming and cheaper. As carried out by engineers, most of safety studies in the building stock are directly related with estimating the probability of collapse and damage in individual buildings. It is necessary to recognize the need for analysis of the building stock not only in terms of structural robustness, but as part of a mitigation plan, taking into consideration all sources of hazards and the urban pattern, densities, landuse, forms of ownership, social features, management capacities, and local opportunities. Risky buildings determined by a simple set of criteria within a comprehensive planning context are comparatively explored in this study to observe the level of fit with those determined by engineering surveys. The case of Fatih District in Istanbul provides an opportunity to carry out comparative analyses. It indicates that a &lsquo / perfect fit&rsquo / can not be achieved if for nothing but due to the disregard of multi-hazard areas, hazardous activities and other vulnerabilities like timber buildings other than reinforced concrete in the district by the engineering survey. Several trials indicated that there is a trade-off between ratio of fit and the total volume of relative vulnerability assumed. Ratios like 70% or more could make the planning approach a preferable method owing to its nature of least time-consuming and costly alternative in the determination of what constitutes risk in any urban area. Ultimate assessment could be made with the occurance of the earthquake itself.

The current study aimed to examine two potential positive outcomes of an earthquake experience, namely posttraumatic growth (PTG) and earthquake preparedness behavior. Variables that may be related to PTG and earthquake preparedness behavior were examined after earthquake victimization by using two models, which were the Person Relative to Event (PrE) Model (Mulilis &amp / Duval, 1997) to understand earthquake preparedness behavior, and Model of Life Crises and Personal Growth (Schaefer &amp / Moos, 1992) to understand PTG. In order to examine earthquake preparedness behavior, the roles of demographic variables, event-related variables, cognitive appraisal factors, and coping strategies, and in order to examine PTG, environmental factors, system factors, event related factors, earthquake specific coping and cognitive appraisal factors, and general ways of coping responses factors were examined. Data was collected by a questionnaire consisting of three parts. The first part was a socio-demographic information form. The second part of the questionnaire included set of items designed to examine past earthquake experience, the severity of past earthquake experience and reasons to prepare for a possible future earthquake. The third part of the questionnaire consisted of eight scales. These scales were Ways of Coping Inventory (WCI) to measure coping strategies used in stressful situations, Revised and Translated Mulilis-Lippa Earthquake Preparedness Scale (MLEPS) to measure the level of earthquake preparedness behavior, perceived difficulty and perceived effectiveness of being prepared, Religiousness Scale (RS) to measure the level of religious resources of participants, The Multidimensional Scale of Perceived Social Support (MSPSS) to measure perceived adequacy of social support, The Quality of Life Scale (WHOQOL) to measure the quality of life of the participants, Psychological Well-Being Scale to measure the level of psychological well-being of participants, Traumatic Stress Symptom Checklist (TSSC) to measure posttraumatic stress, and Post-traumatic Growth Inventory (PTGI) to measure stress-related growth. One hundred ninety nine adults (105 females and 94 males with an age range of 18 to 73) were participants of the study. The participants were from Kaynasli, D&uuml / zce. The participants were selected on the basis of their age, gender, and the type of their houses. They were contacted through home visits. In the result section, the level of the different categories of earthquake preparedness behavior, self-efficacy and outcome efficacy / the reasons of preparedness and nonpreparedness for earthquakes, the variables related to earthquake preparedness behavior and PTG were presented. Hierarchical regression analysis results revealed that perceived responsibility to prepare for earthquakes, outcome efficacy, and problem-focused coping were positively and posttraumatic stress was negatively related to earthquake preparedness behavior. As a result of the regression analysis, it was found that being married, perceived social support, well-being, problem-focused coping, and seeking social support coping were significant predictors of the level of PTG. The results of regression analysis also showed that, general problem focused coping was more efficient than earthquake specific active coping after earthquake victimization for the development of PTG. The results of the study were discussed within the relevant literature, shortcomings of the current study, clinical implications and suggestions for future research were proposed.

Recovery from disaster is a challenging period for any community. Long-term recovery is important, especially in relation to the built heritage, but it is among the least explored phases of disaster. Identifying past problems is needed to reduce future recovery complications. This study investigates the long-term recovery of public and Non-Government Organizations (NGO) owned historic buildings after an earthquake in the light of chosen sustainability variables. It examines San Francisco after the 1989 Loma Prieta earthquake as a case study and analyzes time needs, community participation, and maintenance of historic character, to identify whether historic buildings faced special issues and the variables involved. The study uses different methods. It statistically compares data for a sample of public and NGO owned buildings in San Francisco and then analyzes the dynamics of recovery for three buildings that faced delays. The study has found that historic buildings faced delays in recovery but such delays were sometimes the results of major rehabilitation projects, thus having long-term benefits. There are many variables in the recovery process that delay historic buildings and can be addressed to reduce future delays, which are mostly results of the context, process, and players. Time needs for the recovery of buildings are affected by their function, damage level, and status. Also, the sustainability of the process needs to be addressed, mainly in terms of the way historic buildings are valued, and the degree to which such valuation allows them to be part of the heritage of the community at large.

Deep non-volcanic tremor is a newly discovered seismic phenomenon with low amplitude, long duration, and no clear P- and S-waves as compared with regular earthquake. Tremor has been observed at many major plate-boundary faults, providing new information about fault slip behaviors below the seismogenic zone. While tremor mostly occurs spontaneously (ambient tremor) or during episodic slow- slip events (SSEs), sometimes tremor can also be triggered during teleseismic waves of distance earthquakes, which is known as "triggered tremor". The primary focus of my Ph.D. work is to understand the physical mechanisms and necessary conditions of triggered tremor by systematic investigations in different tectonic regions. These include Taiwan, California, southwest Japan, Alaska and the Aleutian Arc, Cascadia, and New Zealand. In the first chapter of my dissertation, I conduct a systematic survey of triggered tremor beneath the Central Range (CR) in Taiwan for 45 teleseismic earthquakes from 1998 to 2009 with Mw ≥ 7.5. Triggered tremors are visually identified as bursts of high-frequency (2-8 Hz), non-impulsive, and long-duration seismic energy that are coherent among many seismic stations and modulated by the teleseismic surface waves. A total of 9 teleseismic earthquakes has triggered clear tremor in Taiwan. The peak ground velocity (PGV) of teleseismic surface waves is the most important factor in determining tremor triggering potential, with an apparent threshold of ~0.1 cm/s, or 7-8 kPa. However, such threshold is partially controlled by the background noise level, preventing triggered tremor with weaker amplitude from being observed. In addition, I find a positive correlation between the PGV and the triggered tremor amplitude, which is consistent with the prediction of the 'clock-advance' model. This suggests that triggered tremor can be considered as a sped-up occurrence of ambient tremor under fast loading from the passing surface waves. Finally, the incident angles of surface waves also play an important rule in controlling the tremor triggering potential. The next chapter focuses on a systematic comparison of triggered tremor around the Calaveras Fault (CF) in northern California (NC), the Parkfield-Cholame section of the San Andreas Fault (SAF) in central California (CC), and the San Jacinto Fault (SJF) in southern California (SC). Out of 42 large (Mw ≥7.5) earthquakes between 2001 and 2010, only the 2002 Mw 7.9 Denali fault earthquake triggered clear tremor in NC and SC. In comparison, abundant triggered and ambient tremor has been observed in CC. Further analysis reveal that the lack of triggered tremor observations in SC and NC is not simply a consequence of their different background noise levels as compared to CC, but rather reflects different background tremor rates in these regions. In the final chapter, I systematically search for triggered tremor following the 2011 Mw9.0 Tohoku-Oki earthquake in the regions where ambient or triggered tremor has been found before. The main purpose is to check whether triggered tremor is observed in regions when certain conditions (e.g., surface wave amplitudes) are met. Triggered tremor is observed in southwest Japan, Taiwan, the Aleutian Arc, south-central Alaska, northern Vancouver Island, the Parkfield-Cholame section of the SAF in CC and the SJF in SC, and the North Island of New Zealand. Such a widespread triggering of tremor is not too surprising because of the large amplitude surface waves (minimum peak value of ~0.1 cm/s) and the associated dynamic stresses (at least ~7-8 kPa), which is one of the most important factors in controlling the triggering threshold. The triggered tremor in different region is located close to or nearby the ambient tremor active area. In addition, the amplitudes of triggered tremor have positive correlations with the amplitudes of teleseismic surface waves among many regions. Moreover, both Love and Rayleigh waves participate in triggering tremor in different regions, and their triggering potential is somewhat controlled by the incident angles. In summary, systematically surveys of triggered tremor in different tectonic regions reveal that triggered tremor shares similar physical mechanism (shear failure on the fault interface) as ambient tremor but with different loading conditions. The amplitude of the teleseismic surface wave is one of the most important factors in controlling the tremor triggering threshold. In addition, the frequency contents and incident angles of the triggering waves, and local fault geometry and ambient conditions also play certain roles in determining the triggering potential. On the other hand, the background noise level and seismic network coverage and station quality also could affect the apparent triggering threshold. Because triggered tremor occurs almost instantaneously during the teleseismic surface waves, and the tremor amplitude is somewhat controlled by the amplitude of the triggering waves, the occurrence time and the size of the triggered tremor could be somewhat predictable, so long as we know the amplitude and period of surface waves and associated time-varying dynamic stresses. Hence, further analysis of triggered tremor may provide important new clues on the nucleation and predictability of seismic events.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 256-262). Available also in a digital version from Dissertation Abstracts.

Tez (Yüksek Lisans) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Jeofizik Mühendisliği Anabilim Dalı, 2007. / Kaynakça var.

Tez (Doktora) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, İnşaat Mühendisliği Anabilim Dalı, 2008. / Kaynakça var.