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dc.contributor.authorLasley, Samuel Jamesen_US
dc.date.accessioned2015-09-28T13:52:35Z
dc.date.available2015-09-28T13:52:35Z
dc.date.issued2015-08-21en_US
dc.identifier.othervt_gsexam:6121en_US
dc.identifier.urihttp://hdl.handle.net/10919/56659
dc.description.abstractEarthquake-induced liquefaction of saturated soils and seismic compression of unsaturated soils are major sources of hazard to infrastructure, as attested by the wholesale condemnation of neighborhoods surrounding Christchurch, New Zealand. The hazard continues to grow as cities expand into liquefaction- and seismic compression-susceptible areas hence accurate evaluation of both hazards is essential. The liquefaction evaluation procedure presented herein is based on dissipated energy and an SPT liquefaction/no-liquefaction case history database. It is as easy to implement as existing stress-based simplified procedures. Moreover, by using the dissipated energy of the entire loading time history to represent the demand, the proposed procedure melds the existing stress-based and strain-based liquefaction procedures in to a new, robust method that is capable of evaluating liquefaction susceptibility from both earthquake and non-earthquake sources of ground motion. New relationships for stress reduction coefficient (r_d) and number of equivalent cycles ($n_{eq}$) are also presented herein. The r_d relationship has less bias and uncertainty than other common stress reduction coefficient relationships, and both the $n_{eq}$ and $r_d$ relationships are proposed for use in active tectonic and stable continental regimes. The $n_{eq}$ relationship proposed herein is based on an alternative application of the Palmgren-Miner damage hypothesis, shifting from the existing high-cycle, low-damage fatigue framework to a low-cycle framework more applicable to liquefaction analyses. Seismic compression is the accrual of volumetric strains caused by cyclic loading, and presented herein is a "non-simplified" model to estimate seismic compression. The proposed model is based on a modified version of the Richart-Newmark non-linear cumulative damage hypothesis, and was calibrated from the results of drained cyclic simple shear tests. The proposed model can estimate seismic compression from any arbitrary strain time history. It is more accurate than other "non-simplified" seismic compression estimation models over a greater range of volumetric strains and can be used to compute number-of-equivalent shear strain cycles for use in "simplified" seismic compression models, in a manner consistent with seismic compression phenomenon.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectearthquakesen_US
dc.subjectdissipated energyen_US
dc.subjectliquefactionen_US
dc.subjectfatigueen_US
dc.subjectseismic compressionen_US
dc.titleApplication of Fatigue Theories to Seismic Compression Estimation and the Evaluation of Liquefaction Potentialen_US
dc.typeDissertationen_US
dc.contributor.departmentCivil and Environmental Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineCivil Engineeringen_US
dc.contributor.committeechairRodriguez-Marek, Adrianen_US
dc.contributor.committeechairGreen, Russell A.en_US
dc.contributor.committeememberChapman, Martin C.en_US
dc.contributor.committeememberEatherton, Matthew Royen_US


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