Advanced application of seismic cone penetration test at complex ground conditions

• Advanced applications of SCPTù are presented at SRS with complex geologic setting.
• Unusual trends and stress-dependency of in-situ Vs were observed at SRS site.
• Cementious bonding and/or highly structured geologic units were identified by SCPTù.
• SCPTù data allowed the investigation of site-specific calcareous soil deposits.
• Large voids and/or caverns in special soft zone were successfully detected.

Seismic piezocone test (SCPTù) is a representative geophysical and geotechnical in-situ test which can generate multiple types of independent readings and collect relatively continuous data, as well as investigate both vertical and lateral spatial variability for geo-characterization. This study presents special and advanced applications of SCPTù towards geotechnical site investigations in west central South Carolina, US, which consists of very complex soil formations and unusual geologic settings. The special geologic conditions include apparent gap-graded soils, calcareous soils, cementious bonding, desiccation, ageing, and the dissolutioning of old calcareous sediments (Santee Formation) at depths of 40 to 50 meter below grade, similar to karstic limestone deposits. Especially, diagenetic processes in the Santee carbonate mineral sediments have resulted in caves, voids, and infilled soft soil zones within the soil matrix at these elevations. The data obtained from SCPTù system are successfully utilized for assessing the various special geologic conditions. Furthermore, a unique example is introduced to represent the powerful application of SCPTù toward special void detection.