Evaluating drained shear strength of sands by shear wave velocity from a critical state perspective
摘要
This paper presents a novel method for estimating shear strength of sands by using shear wave velocity Vs. The key of the method is a correlation between Vs and the peak stress ratio (q/p’)p, established through a comprehensive experimental program comprising small-strain shear wave measurements and large-strain drained triaxial compression tests conducted over a wide range of states of sands. By analyzing the data within the framework of critical state soil mechanics, the stress ratio factor K, defined as the ratio of peak stress ratio (q/p’)p and critical state stress ratio (q/p’)cs, is uniquely linked to the initial state parameter ψ0. Furthermore, using the relation between stress-corrected shear wave velocity Vs1 and ψ0, the stress ratio factor K is related to Vs1. The salient feature of the relationship lies in its sound theoretical framework, offering a lucid illustration of the interplay between small-strain and large-strain behavior, encompassing the combined influence of void ratio, confining pressure, and soil characteristics concurrently. The new relationship is substantiated using extant literature data, and the parameters involved can be readily fine-tuned, thereby showing a great potential in geotechnical engineering applications.