Unified correlation between SPT–N and shear wave velocity for a wide range of soil types considering strain-dependent behavior. Issue 126 (November 2019)

• Record Type: Journal Article
• Authors: Tsai, Chi-Chin; Kishida, Tadahiro; Kuo, Chun-Hsiang
• Is Part Of: Soil dynamics and earthquake engineering. Issue 126(2019)
• Publication Date: 2019-11
• Subjects: Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2019.105783
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: The shear wave velocity (Vs ) of sediments plays a key role in seismic wave amplification and is required in site response analysis. Such information is usually lacking during field exploration, but standard penetration test blow count (N) is typically available. Therefore, several studies have established empirical correlations between N and Vs for engineering use. However, these empirical correlations significantly vary in terms of model form and are only applicable to specific soil types, such as sand or clay. A unified empirical correlation for a wide range of soil types, which contains several soil properties (e.g., liquid limit and plasticity index (PI)) in addition to the Vs and N of strata, is developed in this study using the Engineering Geological Database for the Taiwan Strong Motion Instrumentation Program. Influences of confining stress, fines content (FC), PI, and soil types on small-strain properties (i.e., Vs ) and large-strain measurements (i.e., N) are first evaluated through the developed correlations with these parameters. The unified correlation between Vs and N that is dependent on confining stress, FC, and PI is then proposed through the conditional prediction approach. The model successfully applies to different regions in Taiwan that includes various types of soil deposits and, thus, is potentially used for the other regions. Highlights: A unified correlation between SPT–N and Vs for a wide range of soil types is developed. The model considers the different behaviors of small strain (Vs) and large strain (SPT-N). The model is developed based on the conditional prediction approach. The model contains confining stress, fines content, and plasticity index in addition to the Vs and N. The model successfully applies to different regions in Taiwan and is potentially used for the other countries.