Requirements for soil-specific correlation between shear wave velocity and liquefaction resistance of sands

• CRR–Vs correlation is not unique for sands and is soil-specific.
• The existing method can only be used as an initial estimation of liquefaction resistance.
• The soil-specific CRR–Vs1 curves are likely to be located in a proposed region.
• Measuring the field Vs, a specified area can be classified into three zones.
• The soil-specific CRR–Vs1 correlation is required in one zone of the three zones.

The application of the simplified method for evaluating the liquefaction potential based on shear wave velocity measurements has increased substantially due to its advantages, especially for microzonation of liquefaction potential. In the simplified method, a curve is proposed to correlate the cyclic resistance ratio (CRR) with overburden stress-corrected shear wave velocity (Vs1). However, the uniqueness of this curve for all types of soils is questionable. The objective of this research is to study whether the correlation between CRR and Vs1 is unique or not. Besides, the necessity of developing the soil-specific correlations is also investigated. Based on laboratory test data, a new semi-empirical method is proposed to establish the soil-specific CRR–Vs1 correlation. To validate the proposed method, a number of undrained cyclic triaxial tests along with bender element tests were performed on two types of sands. Similar experimental data for six other types of sands reported in the literature was also compiled. Applying the proposed method, soil-specific CRR–Vs1 correlation curves were developed for these eight types of sands. It is shown that the correlation is not unique for different types of sands and the boundary curve proposed in the available simplified method can only be used as an initial estimation of liquefaction resistance. Finally, using the results of this study as well as previous ones, a chart is suggested to be used in engineering practice showing the conditions for which a detailed soil-specific CRR–Vs1 correlation study needs to be performed.