Cyclic Resistance Ratio of a Pleistocene-Age Deposit at the CREC Site in South Carolina: Fid-Bau Portal

Cyclic Resistance Ratio of a Pleistocene-Age Deposit at the CREC Site in South Carolina

Gassman, Sarah L. / Hasek, Michael J.

The liquefaction susceptibility of aged soils is an ongoing concern in the Southeastern US due to the recurrence of earthquakes in the South Carolina Coastal Plain (SCCP). This paper presents the results from a laboratory study to assess the cyclic resistance ratio of a Pleistocene-age soil deposit within the SCCP where no evidence of liquefaction or paleo-liquefaction has been observed. The potentially liquefiable deposit studied herein is about 33,000–85,000 years old. Stress-controlled cyclic triaxial tests were performed on three types of specimens from the deposit: specimens that were obtained from fixed piston tube samples and frozen ex situ, specimens that were cored from frozen ground, and specimens that were reconstituted using water pluviation. The range of cyclic stress ratios for the specimens obtained by fixed piston tube sampling and those obtained by coring frozen ground were similar. The reconstituted specimens maintained significantly lower cyclic stress ratios than the cyclic stress ratios of both the in situ and ex situ frozen specimens at initial liquefaction. An aging factor of 1.4 was derived by comparing the cyclic triaxial results from the fixed piston tube specimens and the reconstituted specimens.