| Lateral spreading occurs when a mass of soil moves from one location to another, typically during an earthquake. Especially vulnerable to lateral spreading is soil that is arranged in a slope, as there is a great potential for soil to move from a higher location to a lower one. In addition, soil liquefaction is a phenomenon that is often caused by seismic shaking, with great potential for harm to lives and property. The destructive aftermaths of slope failures and liquefaction provide significant motivation to better understand these hazards. The goal of this dissertation is to determine what influence seismological and local site effects have on the mechanics of lateral spreading.; To this end, a rational method to simulate ground motion which incorporates the spatial variability of ground motion and relative source location is developed. The earth medium is modeled as a layered half space with the source located within the half space. The source is described by the specific barrier model, one of the best currently available, since it has both a physical meaning and a mathematical basis. This source is discretized into a number of double couple sources; the Green's functions are calculated with the appropriate time lags to arrive at the analytical solution of the frequency-wave number spectra, which effectively describe the temporal and spatial variability of the earthquake ground motion. To obtain the displacement, velocity and acceleration time histories at any point on the ground surface, the complex Fourier amplitudes in the frequency-wave number domain are transformed into the time-space domain. Source parameters from the Loma Prieta earthquake are then used in the deterministic simulation.; The resulting ground motions are applied to a finite element model of a sloped embankment, which is comprised of cohesive soil with a thin underlying layer of sand. The liquefaction of this sand layer and the failure of the cohesive slope are studied. |
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