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The objective of this study is to develop a consistent relationship between small strain shear wave velocity (Vs), corrected cone penetration test (CPT) tip resistance (qc1Ncs), and corrected standard penetration test (SPT) blow count (N1,60cs) for liquefiable soils. In the absence of actual measurements of Vs in the field, it is common to use data from SPT or CPT testing to estimate Vs. However, empirical correlations between pairs of these in situ metrics can yield significantly different values of Vs. Using recent correlations between cyclic resistance ratio normalized to M7.5 (CRRM7.5) and Vs normalized to one atmosphere of overburden (Vs1), qc1Ncs, or N1,60cs, a consistent relationship is developed such that reasonably similar values of Vs can be obtained using either qc1Ncs or N1,60cs. In comparison to two published Vs correlations, the correlations given in this study provide an average Vs value when using N1,60cs as the dependent variable but a slightly lower prediction of Vs when using qc1Ncs as the dependent variable. 

Deep wastewater injection-induced seismicity has led to over a thousand Mw>3 earthquakes and four Mw>5 earthquakes in Oklahoma over the last ten years. The 3 September 2016, Mw5.8 Pawnee, Oklahoma, earthquake was the first induced seismic event worldwide, that the authors are aware of, where liquefaction was observed and documented, raising concerns regarding the liquefaction risk posed by future induced earthquakes. Determining the suitability of current variants of the simplified procedure for evaluating the regional liquefaction hazard caused by induced earthquakes is part of an ongoing study. A detailed site characterization campaign examining profiles where liquefaction was and was not observed following the 2016 Mw5.8 Pawnee, Oklahoma, earthquake is part of this study. The purpose of this paper is to present an overview of the sites targeted as part of this testing, a summary of preliminary results from the site characterization campaign, and a description of planned future testing. 

ASCE 7-16 details how the peak ground acceleration (PGA) should be determined for evaluating liquefaction triggering, with this PGA reflecting the influence of a range of earthquake magnitudes on a site’s seismic hazard. Similarly, the Finn and Wightman magnitude-weighting scheme can be used to account for the full range of magnitudes influencing the seismic hazard at a site, where the weights are derived from a site’s seismic hazard deaggregation data. However, the deaggregation data for the seismic hazard maps for the Central/Eastern U.S. are only available for rock motions and not motions at the surface of the soil profile. The authors explore this issue by comparing the weighted average magnitude scaling factors (MSF) and depth-stress weighting factor (rd) values for multiple sites in the Western U.S. developed using deaggregation data for rock motions and for motions at the surface of the soil profiles. Based on these comparisons, the authors found that using the PGA deaggregation data for rock conditions yield similar weighted averages for MSF and rd as those computed using deaggregation data for the PGA at the surface of the soil profile.