The large number of bridge collapses that have occurred in recent earthquakes has exposed the vulnerabilities in existing bridges. One of the emerging tools for protecting bridges from the damaging effects of earthquakes is the use of isolation systems. Seismic isolation is achieved via inserting flexible isolator elements into the bridge that shift the vibration period and increase energy dissipation. To date, the structural performance of bridges incorporating sliding seismic isolation is not well-understood, in part due to the lack of adequate models that can account for the complex behavior of the isolators. This study investigates and makes recommendations on the structural performance of bridges utilizing sliding type seismic isolators, based on the development of state-of-the-art analytical models. Unlike previous models, these models can account simultaneously for the variation in the normal force and friction coefficient, large deformation effects, and the coupling of the vertical and horizontal response during motion. The intention is to provide support for seismic risk mitigation and insight for the analysis and design of seismically isolated bridges by quantifying response characteristics. The level of accuracy required for isolator analytical models used in typical highway bridges are assessed. The comparative viability of the two main isolator types (i.e. sliding and elastomeric) for bridges is investigated. The influence of bridge and sliding isolator design parameters on the system s seismic response is illustrated.

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.

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (p. 129-142). Also available in print.

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on Jan. 11, 2010. Major professor: Daniel C. Jansen. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Civil and Environmental Engineering." "December 2009." Includes bibliographical references (p. 176-180).

Thesis (Ph. D.)--Lehigh University, 2003. / In three parts. Includes vita. Includes bibliographical references (leaves 770-775).

A confined masonry (CM) wall consists of a masonry wall panel surrounded by reinforced concrete (RC) members on its perimeters. Low-rise CM structures are widely used in earthquake-risked (EQ-risked) rural or suburban areas all over the world. Most of these structures fail in shear pattern under lateral EQ loads, and some of them collapse under a severe or even a moderate EQ due to inappropriate design. On the other hand, buildings constructed of RC frames have much better performance in resisting EQs, since their RC members have larger dimensions and heavier reinforcing ratios than those in CM structures. Nonetheless, RC-frame buildings are normally too expensive for most inhabitants in less developed regions. In this study, as an improvement to the conventional CM buildings for EQ resistance and for the sake of post-EQ restoration, a hybrid masonry – RC (HMR) structure, whose working mechanism is different from that of a conventional CM structure, is proposed. The RC members (i.e. “tie beams” and “tie columns”), which function only as confinement in a CM building, will resist most of gravity load and part of lateral EQ load in an HMR structure, while the wall panels will take most of lateral EQ load and part of gravity load. This is achievable by slightly increasing the sizes and reinforcing ratios of RC members in HMR structures. Such buildings will not collapse in the absence of masonry wall panels because the gravity load bearing system is still intact. On the other hand, as the wall panels in the proposed HMR structure will absorb most of the energy induced by lateral EQ load, severe damages will be controlled within the wall panel region, so that only the wall panels need to be replaced instead of rebuilding the whole structure after the EQ event. To investigate the mechanical behaviours of masonry assemblages to be used in HMR structures, a series of experimental tests were conducted. Having established the relevant material properties for HMR structures, finite element (FE) simulation was performed to verify its work mechanism. Prior to applying the FE simulation to HMR structures, the FE technique was first applied to simulate the behaviours of two concrete-brick masonry panels under diagonal compression loading and a CM wall under cyclic lateral loading. The results show a good correlation between the experimental results and the simulated ones. This has validated the feasibility of using the FE software to study the proposed HMR structure. The theoretical simulation results show that in a properly designed HMR wall, depending on the masonry reinforcing details and the boundary conditions of simulated load cases, about 70% of the gravity load imposed on the RC beam will be transferred to the RC columns and more than 80% of the seismic energy (in terms of strain energy) will be absorbed by the masonry panel. Therefore, it is obvious that the proposed HMR structure is very feasible to replace the conventional CM structure in resisting EQ attacks with no risk of collapse. / published_or_final_version / Civil Engineering / Master / Master of Philosophy

No description available.

A survey of earthquake disaster mitigation strategies and building principles which could applied in rural areas of the Less Developed Countries. Earthquake vulnerability of traditional buildings and problems of earthquake hazard mitigation in these countries are discussed, along with some strategies that may help reduce the impact of future earthquakes. The performance of rural buildings during past earthquakes is analyzed to have a clear understanding of building behaviour during an earthquake. After the analysis, the research traces various recommendations and safe building techniques that would improve the earthquake-resistance of these buildings. Moreover, the study reviews problems often involved in implementing mitigation measures and in transferring technical information to semi-illiterate and unskilled workers, in conjunction with some methodologies on how to transfer information to the rural population. The study concludes by outlining the urgency for the need of pre-earthquake mitigation strategies and suggests some ideas to help narrow the gap which exists between the available information on earthquake mitigation measures and its application in those countries most affected by earthquakes.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 36-38). / x, 38 leaves, bound ill., map 29 cm

Addendum is pasted to back end-paper. / Bibliography: leaves 203-215. / xiii, 215 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on the behaviour and design of unreinforced masonry buildings when subjected to forces induced into the structure from earthquake ground motion. The study involves the monitoring of ambient vibrations in a number of unreinforced masonry buildings in Adelaide to identify their dynamic properties. / Thesis (Ph.D.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 1996