Shear wave method has been increasingly popular in assessing the liquefaction potential of granular soils. Two particle-scale parameters, the inter-particle friction and the shear modulus of grains, play vital roles in correlation between Cyclic Resistance Ratio (CRR) and shear wave velocity corrected by overburden stress (Vs1). Series of drained one-dimensional compression tests were simulated on samples of different inter-particle friction angles assigned during preparation stage. Uniformity coefficients of these Particle Size Distribution (PSD) curves are 2 and 4 whose average particle size d50 are identical. The shearing results, as well as their assigned inter-particle friction angles form calibration curves for real sands. Dissimilar PSD curves result in different calibration outcomes. For Silica sand no.8, these curves give divergent interparticle friction angles. This study calibrates particle shear modulus for Silica sand no.8 as well. Different PSD curves give divergent values of particle shear modulus. PSDs show impacts on calibrations of both vital parameters, which have converse effects on CRR-Vs1 curves. This study suggests that the CRR-Vs1 correlation should be independent of PSDs.

Abstract. This study investigated the kinematic and kinetic differences among the different levels of taekwondo axe kick among female taekwondo jins using the Vicon 3D motion analysis system and Kistler force plates. Independent t-tests were used to detect the differences. The high-level group was designated the senior group (SG), and the low-level group was designated the junior group (JG). Kinematics data showed that SG had more pelvis rotation (p < 0.05), earlier time of the lowest attract point (p < 0.05), and higher peak value of velocity curve (p < 0.05) than JG. No differences were observed between the two groups in terms of the lowest attack curve. Kinetics data showed that the peak ground reaction forces (GRF) in the vertical direction in SG were higher (p < 0.05) than those of JG; the peak force in SG was also exhibited earlier (p < 0.05) than that in JG. Therefore, differences were detected in the pelvis rotation, peak value in attack velocity, and GRF in the anterior-posterior direction between SG and JG. These factors also increased the attack velocity and range in SG.