Investigations into the behaviour of precast buildings under earthquake loading have shown that the connections are likely to be the weakest link in a pre-cast structure, and the stability of the structure under earthquake loading depends upon the strength & stability of these connections. A 2-dimensional non-linear dynamic analysis of a one storey box-type pre-cast buildings is presented. The shear walls in the buildings are modelled by linear springs, the properties of which depend upon the connections connecting the rigid panels of the shear walls. To check the effectiveness of the NBCC code design, computer studies have been made on a box-type building statically designed for different eccentricities. The strength of the shear walls was calculated assuming that each panel was a cantilever fixed at the base with dowel bars providing the flexural steel. To make the building survive a major earthquake, we need dowel connections that can take 5mm to 6mm elongation which can be easily accommodated. Studies have also shown that under the action of an earthquake, the response of a highly unsymmetrical building will not be very different from that of a symmetric building as long as the building is properly designed using the NBCC code provisions for earthquake loading. It has also been shown that the NBCC code design eccentricity equation is somewhat conservative in calculating the design eccentricity and that a small change in the stiffness of walls perpendicular to the direction of earthquake has little effect on the response of the structures. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 140-141. / by Chin Pang Wong. / M.S.

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The available earthquake records are classified into five groups according to their site stiffness and epicentral distance as the grouping parameters. For the groups thus defined, normalized response spectra are obtained for single-degree-of-freedom and massless oscillators. The effectiveness of the grouping scheme is examined by studying the variance of response quantities within each group. The implicit parameters of average frequency and significant duration are obtained for each group and their effect on the response spectra is studied. Correlation analyses between various ground motion characteristics such as peak displacement, velocity, acceleration and root mean square acceleration are carried out for each group. Smoothed design spectra for relative and pseudo velocities and relative acceleration responses of single degree of freedom oscillators and the velocity and acceleration responses of massless oscillators are proposed for each group. Methods to predict relative velocity and relative acceleration spectra directly from the pseudo velocity spectra are presented. It is shown that the relative spectra can be reliably estimated from the pseudo spectra. The site dependent design spectra are defined for a wide range of oscillator periods and damping ratios. / Master of Science

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24172号 / 理博第4863号 / 新制||理||1696(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 宮澤 理稔, 教授 久家 慶子, 准教授 ENESCU Bogdan Dumitru / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

An analytical formulation for seismic analysis of multiply supported secondary systems is developed. The formulation is based on the random vibration theory of structural systems subjected to correlated inputs at several points. The response of the secondary systems is expressed as a combination of the dynamic, pseudo-static and cross response components. The dynamic part is associated with the inertial effect induced by the support accelerations. The pseudo-static part is due to the relative displacement between supports, and the cross part takes into account the correlation between these two parts of the response. The seismic input in this approach is defined in terms of the auto and cross pseudo-acceleration and relative velocity floor spectra. The information about floor displacements and velocities as well as their correlations is required for calculating the pseudo-static and cross response components. These inputs can be directly obtained from the ground response spectra. The interaction effect between the primary and secondary systems is studied. This effect is specially significant when the modes of the secondary system are tuned or nearly tuned to the modes of the primary system. The floor spectral inputs are appropriately modified to take into account this interaction effect. The design response of the secondary system when computed with these modified floor inputs will incorporate the interaction effect. The applicability of the proposed methods is demonstrated by several numerical examples. / Ph. D. / incomplete_metadata

Structures built next to each other in congested cities are likely to pound on each other during strong ground shaking caused by earthquakes. The main objective of this study is to examine the problem of mutual structural pounding to identify its effect on structures and then propose solutions to mitigate its effects. Mutual pounding of structural systems with varying mass, stiffness, and seismic joint gaps, subjected to several different input motions are examined. To evaluate the effects of pounding, the numerical results with and without pounding have been considered. The resilience between two impacting masses is represented by linear springs and also nonlinear Hertz model contact stiffness. Pounding causes a large increase in the shear force in the stories higher than the top pounding story, a large increase in the accelerations of the pounding floors and also large overturning effects on both structures. The parametric study of pounding of structures in series showed that in most cases the corner structures are penalized more than the interior structures. The study of the effect of foundation flexibility on the structural pounding response showed that a proper consideration of this parameter must be included in the analysis. To alleviate the pounding effects to avoid damage to structural elements and supported secondary equipment, it was found necessary to join the structures by rigid links and brace all the stories of at least the taller structure. Joining of the floors is required to reduce the excessive floor accelerations caused by impact, whereas the story bracings are required to reduce the excessive story shears or bending moments in the higher stories caused by pounding of the lower floors. It is observed that except for very soft soils, the proposed pounding mitigation scheme will increase the shear force transmitted to the foundation, thus requiring a strengthening of the foundation as well. Since the forces in the rigid links connecting the two structures were observed to be reasonable, the joining of the two structures does not pose any special problem; it can be easily accomplished by using large-size steel rods hooked properly with both structures. In the case of column pounding where the floors of one structure pound on the columns of the other structure, the pounding mitigation strategy is to provide K-bracings on all pounding columns and diagonal bracing in the other stories to reduce high bending moment in the column, and to rigidly join them to avoid high pounding acceleration. / Ph. D.

On January 12, 2010, a 7.0 wide magnitude earthquake hit Haiti and thousands of Haitians were left to cope with the aftermath, and many mental health concerns began to surface (Amnesty International, 2011; Cénat & Derivois, 2014). The main purpose of this study is to understand post-earthquake psychosocial issues in the Haitian context by studying the experiences of Natives in Haiti. This study provides implications for counseling support from international emergency response workers, counselors, counselor educators interested in providing mental health training in Haiti or other developing countries, and researcher's interested in increasing knowledge that has real impact on mental health issues in Haiti. This study aims to answer: "What are the experiences of Haitian Natives post-2010 earthquake in Haiti and the implications for providing appropriate post-crisis psychosocial support?" <br>This qualitative inquiry used Bronfenbrenner's bio-ecological model of human development (Bronfenbrenner, 2005) as a theoretical framework. Seven Haitian Natives who survived the earthquake in La Ville, Haiti shared their beliefs, personal narratives, and the culturally responsive care they received after the earthquake. Some of the participants also took part in a focus group. Informants' responses were translated and transcribed, and Interpretative Phenomenology Analysis (IPA) was used to analyze the transcription and field notes. Conceptual models captured the process and outcomes of psychosocial issues related to post-earthquake context in this study and were compared with previously developed conceptual frameworks. The findings of the study yielded nine themes and 27 sub themes. The findings suggest that the interviewee's experiences were both negative and positive. Some of the negative experiences were continuous trauma symptoms such as panic, worry, and fear. Some of the positive experiences were unity, leadership development, posttraumatic growth, and new appreciation for professional mental health. Based on the conclusions and results from this study, implications will be stated as they relate to practice, teaching, and scholarship. / School of Education; / Counselor Education and Supervision (ExCES) / PhD; / Dissertation;

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