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Full-Text Articles in Geophysics and Seismology
Probabilistic Analysis Of Slide-Rocking Structures Under Earthquake Loads, Taylor J. Knickerbocker
Probabilistic Analysis Of Slide-Rocking Structures Under Earthquake Loads, Taylor J. Knickerbocker
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Estimates of rare seismic hazard are essential for the resilience of critical infrastructure and facilities. However, these estimates are highly uncertain at long return periods due to the lack of observed earthquake records. Several ground motion prediction equations have been proposed to close this gap and estimate rare seismic demands; however, these models were developed based on more moderate earthquake records and can yield physically unrealizable ground motions when extrapolated to long return periods. For this reason, seismologists have proposed using precariously balanced rocks (PBRs) as a way to constrain rare seismic hazard. PBRs are a type of fragile geologic …
Efficient Intensity Measures Of Slide-Rocking Structures For Precariously Balanced Rocks, Taylor J. Knickerbocker, Christine E. Wittich
Efficient Intensity Measures Of Slide-Rocking Structures For Precariously Balanced Rocks, Taylor J. Knickerbocker, Christine E. Wittich
Department of Civil and Environmental Engineering: Faculty Publications
Precariously balanced rocks (PBRs) and other fragile geologic features are important in both the engineering and seismological communities since they are indicative of the maximum ground motion at a site over the rock’s lifetime. Precariously balanced rocks are individual or stacks of freestanding rocks that tend to respond in rigid body modes when subject to seismic excitation – namely, rocking, sliding, slide-rocking, and free-flight, which can lead to overturning. The seismic response of freestanding structures, such as PBRs, is known to be extremely sensitive to small changes in geometry, position, and earthquake excitation. As such, deterministic methods are limited in …
3-D Reconstructions And Numerical Simulations Of Precarious Rocks In Southern California, Christine E. Wittich, Tara C. Hutchinson, J. Desanto, D. Sandwell
3-D Reconstructions And Numerical Simulations Of Precarious Rocks In Southern California, Christine E. Wittich, Tara C. Hutchinson, J. Desanto, D. Sandwell
Department of Civil and Environmental Engineering: Faculty Publications
Reliable estimates of seismic hazard are essential for the development of resilient communities; however, estimates of rare, yet high intensity earthquakes are highly uncertain due to a lack of observations and recordings. Lacking this data, seismic hazard analyses may be based on extrapolations from earthquakes with more moderate return periods, which can lead to physically unrealistic earthquake scenarios. However, the existence of certain precariously balanced rocks (PBRs) has been identified as an indicator of an upper bound ground motion, which precludes toppling of the balanced rock, over its lifetime. To this end, a survey of PBRs was conducted in proximity …