Evaluation of Liquefaction Potential of Saturated Sands Based on Resistivity Piezocone Penetration Testing

The liquefaction of saturated soils is a major concern for the earthquake damage of foundation. Due to the difficulty and cost constraint in obtaining high-quality undisturbed samples, in-situ testing is commonly applied to evaluating the potential of soil liquefaction. In high risk projects, a comprehensive evaluation based on various methods is usually adopted, and thus the research on new method to evaluate the liquefaction is still necessary. In this research the feasibility of using resistivity piezocone penetration test (RCPTU) for predicting liquefaction resistance is investigated. The resistivity of saturated silts and sands is measured using RCPTU at a test section of Suqian-Xinyi expressway. First, the relationship between normalized cone tip resistance and resistivity is analyzed and can contribute to the evaluation of soil liquefaction based on resistivity. Second, the study on combination of resistivity and soil behavior type index to directly calculate the cycle resistance ratio (CRR) is conducted with the CRR from Robertson modified liquefaction evaluation model as reference. The influence of thin cohesive layers and transition zones is also analyzed. It is shown that the resistivity and soil behavior type index can be used for effective evaluation of liquefaction potential of saturated soils.