The seismic cone penetration test (SCPTu) is the most efficient means for geotechnicalsite characterization and the evaluation of seismic ground hazards, as it provides up to 5 independent readings in a single sounding: cone tip stress (qT), sleeve friction (fs),penetration porewater pressure (ub), time rate of dissipation (t50), and downhole shearwave velocity (Vs). During SCPTu tests, a very large number of digital measurements arerecorded. The overwhelming data provide more detailed information for engineeringanalysis, but also pose challenges in post-processing of ???information overload???. In thisthesis, software systems including ShearPro, ClusterPro, and InSituData, are developedto automate post processing of these SCPTu data. ShearPro is developed to automate thepost-processing of the shear wave signals. ClusterPro uses the proposed threedimensionalcluster analysis approach for soil stratification. InSituData facilitates thepost processing of penetration data for seismic ground hazards analysis. A new threedimensional soil classification chart is also proposed in this thesis to help discern soil layers that may be subject to seismic ground hazards, such as loose liquefied sands and silty sands.These methods are then applied to SCPTu data collected at previously-identifedpaleoliquefaction sites located in the New Madrid Seismic Zone (NMSZ). Forliquefaction evaluation, the cyclic stress ratio (CSR) is computed using site responseanalysis by DeepSoil and a measured profile of shear waves derived from the 30-mSCPTU soundings and deep suspension loggings in AR and TN. The natural resistance ofthe soil to liquefaction, termed the cyclic resistance ratios (CRRs), is evaluated based on both deterministic procedures and probabilistic procedures. Based on liquefaction evaluation results at selected paleoliquefaction sites, regional CRR criteria for liquefaction are developed for the NMSZ. As even the latest major earthquakes in NMSZ occurred nearly 200 years ago, aging effects might be an important factor to consider inutilizing the liquefaction criteria to assess the seismic parameters associated with the previous earthquakes. The aging effects in the NMSZ were investigated through large scale blast-induced liquefaction tests conducted by the USGS and supplemented by the author by series of CPTs. Then a procedure to estimate seismic parameters associated with previous earthquakes is proposed. It utilizes both the liquefaction criteria based onSCPTu tests and the empirical attenuation relations developed for the correspondingregions. The approach is validated through data evaluation related to the 1989 LomaPrieta earthquakes in California and then applied to previous historic earthquakes in the NMSZ.
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