Within the confines of this study, seismic soil liquefaction triggering potential of a dam foundation is assessed within an integrated probabilistic seismic hazard assessment framework. More specifically, the scheme presented hereby directly integrates effective stress-based seismic soil liquefaction triggering assessment with seismic hazard analysis framework, supported by an illustrative case. The proposed methodology successively, i) processes the discrete stages of probabilistic seismic hazard workflow upon seismic source characterization, ii) numerically develops the target elastic acceleration response spectra for typical rock sites, covering all the earthquake scenarios that are re-grouped with respect to earthquake magnitude and distance, iii) matches the strong ground motion records selected from a database with the target response spectra for every defined scenario, and iv) performs 2-D equivalent linear seismic response analyses of a 56 m high earth fill dam founded on 24 m thick alluvial deposits. Results of seismic response analyses are presented in the form of annual probability of excess pore pressure ratios and seismically-induced lateral deformations exceeding various threshold values. For the purpose of assessing the safety of the dam slopes, phi-c reduction based slope stability analyses were also performed representing post-liquefaction conditions. After having integrated this phi-c reduction analyses results into the probabilistic hazard framework, annual probabilities of factor of safety of slopes exceeding various threshold values were estimated. As the concluding remark, probability of liquefaction triggering, induced deformations and factor of safeties are presented for a service life of 100 years. It is believed that the proposed probabilistic seismic performance assessment methodology which incorporates both phi-c reduction based failure probabilities and seismic soil liquefaction-induced deformation potentials, provides dam engineers a robust methodology to rationally quantify the level of confidence with their decisions regarding if costly mitigation of dam foundation soils against seismic soil liquefaction triggering hazard and induced risks is necessary.

ABSTRACT NEOTECTONICS OF THE KARAMIK GRABEN-AFYON-(ISPARTA ANGLE), SW TURKEY &Ccedil / i&ccedil / ek, Aydin M.Sc., Department of Geological Engineering Supervisor: Prof. Dr. Ali Ko&ccedil / yigit July 2009, 98 pages The Karamik Graben (KG) is 6-17-km-wide, 29-km-long and NNE-SSWtrending active depression located within the Isparta Angle of the Southwestern Turkey extensional neotectonic domain. The KG is bounded by ENE-SSWtrending Karaca&ouml / ren fault zone to the south, the NNE-SSW-trending Ko&ccedil / beyli- Akkonak fault zone to the east, the WNW-ESE-trending AkSehir fault zone to the north, and the NE-SW to NNE-SSW-trending Devederesi fault zone to the west. The KG contains two graben infills separated by an angular unconformity: (1) Middle Miocene-Middle Pliocene deformed infill, and (2) the Upper Pliocenerecent non-deformed infill. Some geological structures reveal that the older infill was accumulated under the control of an extensional tectonic regime (phase-I extension). Analysis of NW-SE-trending folds and some strike-slip faults indicate that the older infill deformed by a short-term NE-SW-directed compression. This contractional event is the last record of the paleotectonic period. Some geological and geophysical evidence indicate that the younger infill has been deposited under the control of an extensional tectonic regime (phase-II extension). Analysis of some slickensides implies that the current tectonic regime is being characterized by a multi-directional extension in predominantly N-S, E-W and NW-SE directions. This multi-directional extension dominates the Plio- Quaternary neotectonic period initiated Late Pliocene. Total throw amounts accumulated along the margin boundary faults imply that subsidence rates are ~0.15 mm/yr and ~0.21 mm/yr since Late Pliocene. Some of the northern margin-boundary faults of the KG reactivated during the neotectonic period as evidenced by 2002.02.02 Mw = 6.5 &Ccedil / ay earthquake. However, the rest of these faults are still active and they keep their nature of seismic gap.

In today&rsquo / s world, buried structures are used for a variety of purposes in many areas such as transportation, underground depot areas, metro stations and water transportation. The serviceability of these structures is crucial in many cases following an earthquake / that is, the earthquake should not impose such damage leading to the loss of serviceability of the structure. The seismic design methodology utilized for these structures differs in many ways from the above ground structures. The most commonly utilized approach in dynamic analysis of underground structures is to neglect the inertial forces of the substructures since these forces are relatively insignificant contrary to the case of surface structures. In seismic design of these underground structures, different approaches are utilized like free-field deformation approach and soil-structure interaction approach. Within the confines of this thesis, seismic response of highway tunnels is considered through a case study on Bolu Tunnels, which are well documented and subjected to D&uuml / zce earthquake. In the analyses, the seismic response of a section of the Bolu tunnels is examined with 2-D finite element models and results are compared with the recorded data to evaluate the capability of the available analysis methods. In general, the results of analyses did not show any distinct difference from the recorded data regarding the seismic performance of the analyzed section and that the liner capacities were sufficient, which is consistent with the post earthquake condition of the Bolu Tunnels.

This master thesis will be focusing on prefabricated temporary houses and settlements in Kocaeli &ndash / as a place-making process &ndash / throughout post disaster reconstruction period of 1999 Marmara Earthquakes. Main stimulant for this research is the lack of acknowledgement of transforming urban and social environments under the overwhelming forces of disasters both in academic and professional domains in the country. Appropriation and self-identification of temporary accommodation is a way of adaptation and a reaction to disruption caused by forced relocation due to disasters. Personalization process transforms the houses into homes, spaces into places. This transformation is to be analyzed within the framework of altering urban areas, disasters and adaptation processes of householders for the resumption of home. Case study will be based on temporary housing settlements &ndash / prefabricated houses &ndash / in city of Kocaeli. The aim of this work is to understand the effective forces operating during post disaster temporary housing periods, to improve reconstruction and planning processes with the information generated out of the research and to provide data for the policy-making authorities and academic field.

This study investigates the relationship between the ancient settlements in west Anatolia and physical, environmental parameters including topography, rock and morphological classes. Modern settlements are also included in the study to analyze if the response has changed to these parameters from past to the present. The databases created in the study include three topographic attributes (elevation, slope and aspect), rock type, ancient settlements and modern settlements. Analyses performed in the study involve distance and density analyses, morphological analysis / distribution within the rock types both for ancient and modern settlements. The results of the study demonstrated that 1) the active faults produced attractive topography to settle, 2) people preferred the vicinity of the fault line as settlement location, and 3) they were not aware of the earthquake potential of their location. Therefore, because of the advantage of the location they did not consider to change the place as indicated by rebuilding their settlement repeatedly at the same place after it is damaged.

My dissertation focuses primarily on the following three aspects associated with passing seismic waves in the field of earthquake seismology: temporal changes of fault zone properties, nonlinear site response, and dynamic triggering. Quantifying the temporal changes of material properties within and around active fault zones (FZ) is important for better understanding of rock rheology and estimating the strong ground motion that can be generated by large earthquakes. As high-amplitude seismic waves propagate through damaged FZ rocks and/or shallow surface layers, they may produce additional damage leading to nonlinear wave propagation effects and temporal changes of material properties (e.g., seismic velocity, attenuation). Previous studies have found several types of temporal changes in material properties with time scales of tens of seconds to several years. Here I systematically analyze temporal changes of fault zone (FZ) site response along the Karadere-Düzce branch of the North Anatolian fault that ruptured during the 1999 İzmit and Düzce earthquake sequences. The coseismic changes are on the order of 20-40%, and are followed by a logarithmic recovery over an apparent time scale of ~1 day. These results provide a bridge between the large-amplitude near-instantaneous changes and the lower-amplitude longer-duration variations observed in previous studies. The temporal changes measured from this high-resolution spectral ratio analysis also provide a refinement for the beginning of the longer more gradual process typically observed by analyzing repeating earthquakes. An improved knowledge on nonlinear site response is critical for better understanding strong ground motions and predicting shaking induced damages. I use the same sliding-window spectral ratio technique to analyze temporal changes in site response associated with the strong ground motion of the Mw6.6 2004 Mid-Niigata earthquake sequence recorded by the borehole stations in Japanese Digital Strong-Motion Seismograph Network (KiK-Net). The coseismic peak frequency drop, peak spectral ratio drop, and the postseismic recovery time roughly scale with the input ground motions when the peak ground velocity (PGV) is larger than ~5 cm/s, or the peak ground acceleration (PGA) is larger than ~100 Gal. The results suggest that at a given site the input ground motion plays an important role in controlling both the coseismic change and postseismic recovery in site response. In a follow-up study, I apply the same sliding-window spectral ratio technique to surface and borehole strong motion records at 6 KiK-Net sites, and stack results associated with different earthquakes that produce similar PGAs. In some cases I observe a weak coseismic drop in the peak frequency when the PGA is as small as ~20-30 Gal, and near instantaneous recovery after the passage of the direct S waves. The percentage of drop in the peak frequency starts to increase with increasing PGA values. A coseismic drop in the peak spectral ratio is also observed at 2 sites. When the PGA is larger than ~60 Gal to more than 100 Gal, considerably stronger coseismic drops of the peak frequencies are observed, followed by a logarithmic recovery with time. The observed weak reductions of peak frequencies with near instantaneous recovery likely reflect nonlinear response with essentially fixed level of damage, while the larger drops followed by logarithmic recovery reflect the generation (and then recovery) of additional rock damage. The results indicate clearly that nonlinear site response may occur during medium-size earthquakes, and that the PGA threshold for in situ nonlinear site response is lower than the previously thought value of ~100-200 Gal. The recent Mw9.0 off the Pacific coast of Tohoku earthquake and its aftershocks generated widespread strong shakings as large as ~3000 Gal along the east coast of Japan. I systematically analyze temporal changes of material properties and nonlinear site response in the shallow crust associated with the Tohoku main shock, using seismic data recorded by the Japanese Strong Motion Network KIK-Net. I compute the spectral ratios of windowed records from a pair of surface and borehole stations, and then use the sliding-window spectral ratios to track the temporal changes in the site response of various sites at different levels of PGA The preliminary results show clear drop of resonant frequency of up to 70% during the Tohoku main shock at 6 sites with PGA from 600 to 1300 Gal. In the site MYGH04 where two distinct groups of strong ground motions were recorded, the resonant frequency briefly recovers in between, and then followed by an apparent logarithmic recovery. I investigate the percentage drop of peak frequency and peak spectral ratio during the Tohoku main shock at different PGA levels, and find that at most sites they are correlated. The third part of my thesis mostly focuses on how seismic waves trigger additional earthquakes at long-range distance, also known as dynamic triggering. Previous studies have shown that dynamic triggering in intraplate regions is typically not as common as at plate-boundary regions. Here I perform a comprehensive analysis of dynamic triggering around the Babaoshan and Huangzhuang-Gaoliying faults southwest of Beijing, China. The triggered earthquakes are identified as impulsive seismic arrivals with clear P- and S-waves in 5 Hz high-pass-filtered three-component velocity seismograms during the passage of large amplitude body and surface waves of large teleseismic earthquakes. I find that this region was repeatedly triggered by at least four earthquakes in East Asia, including the 2001 Mw7.8 Kunlun, 2003 Mw8.3 Tokachi-oki, 2004 Mw9.2 Sumatra, and 2008 Mw7.9 Wenchuan earthquakes. In most instances, the microearthquakes coincide with the first few cycles of the Love waves, and more are triggered during the large-amplitude Rayleigh waves. Such an instantaneous triggering by both the Love and Rayleigh waves is similar to recent observations of remotely triggered 'non-volcanic' tremor along major plate-boundary faults, and can be explained by a simple Coulomb failure criterion. Five earthquakes triggered by the Kunlun and Tokachi-oki earthquakes were recorded by multiple stations and could be located. These events occurred at shallow depth (< 5 km) above the background seismicity near the boundary between NW-striking Babaoshan and Huangzhuang-Gaoliying faults and the Fangshan Pluton. These results suggest that triggered earthquakes in this region likely occur near the transition between the velocity strengthening and weakening zones in the top few kms of the crust, and are likely driven by relatively large dynamic stresses on the order of few tens of KPa.

The advent of Global Positioning System (GPS) has revolutionized geodesy with high accuracy, fast speed, simple use, and low cost. This dissertation investigates three topics on volcano and earthquake-related deformation using GPS measurements and models to demonstrate the power of the new generation of geodetic methods. The three topics include the 2002-2003 continued episodic inflation at Long Valley Caldera in eastern California, the coseismic and postseismic response of the energetic 2008 MW 6.4 Achaia-Elia Earthquake in northwest Peloponnese, Greece, and the interseismic megathrust coupling and forearc sliver transport near the Nicoya Peninsula in northwest Costa Rica.

Risk mitigation decisions for civil infrastructure exposed to rare natural and manmade hazards are often impacted by risk aversion, a behavioral phenomenon in which the decision maker's perception and judgment of risk are systematically distorted, resulting in decisions that might be viewed as excessively conservative when compared to those from a traditional minimum expected cost analysis. This study addresses how decisions regarding structural safety are affected by the attitudes of the decision-maker toward risk using decision models, such as cumulative prospect theory, that allow risk-averse behaviors to be modeled quantitatively. Perspectives on the general characteristics of risk-aversion are first drawn from risk pricing techniques in the insurance industry. These perspectives are then refined for structural engineering applications by investigations of decisions involving seismic retrofit of unreinforced masonry structures in San Francisco, CA and aseismic design of a steel moment frame in Vancouver, BC. Risk attitudes when confronting extreme wind hazards are also assessed using a decision by the North and South Carolina Code Councils to waive a provision in the International Residential Code that would have required additional windborne debris protection in residential construction. An examination of risk attitudes toward competing natural hazards is then introduced by comparing decisions related to wind and seismic effects in areas where both hazards may be significant. These investigations have led to tentative conclusions regarding the role of risk aversion in the assurance of structural safety and in code-related decisions and suggest avenues for future study.

<p>Past decades have witnessed evidence to large-scale upheaval caused by natural disasters. Thus, there is a need for determination of mechanisms through which natural disasters may influence growth, especially for developing countries. This paper traces the medium-short run time path of agricultural and industrial output growth response to four types of disasters in Southern and Southeastern Asian countries. Disasters considered are floods, droughts, storms and earthquakes. The empirical results suggest heterogeneous effects for disasters as well as different economic sectors. In many cases disaster impact was delayed. Generally speaking, floods and droughts have a stronger effect while earthquakes and storms have a weaker one on disaggregated output growth. Floods have a predominantly posi-tive effect while droughts have a negative one on both agricultural and industrial sectors. Storms seem to show a stronger negative effect in the agricultural sector than in industrial sector hinting at existence of short lived indirect effects. Earth-quakes, on the other hand, presented ambiguous growth responses.</p> / No

Inaug.-diss.--Munich. / Lebenslauf. "Literatur": p. 79.