Evaluating the Effect of Soil Particle Characterization on Internal Friction Angle

Abstract

One of the critical design parameters used in evaluating soil structure is the friction angle, derived from Mohr's Circle failure criterion. The soil friction angle is an engineering parameter estimated in the laboratory to quantify the soil shear strength in geotechnical applications. This paper indicates an experimental study investigating the impact of particle size on different sandy soils shear strength behavior. The direct shear test equipment is useful for simulating various stress regimes to determine the soil strength by employing a slow moving lateral force to a consolidated sample along a shear plane. A series of direct shear tests were conducted to investigate the interface behavior of soil. Soil samples were selected from different locations in New Mexico, United States. The influence of soil particle size on the soil's shear strength behavior is discussed by performing a series of symmetric direct shear tests according to ASTM D3080 and analyzing the results. To minimize errors, electronic transducers were used to measure vertical and horizontal displacements. DS7 is geotechnical testing software controlling the test by utilizing a data logger. The investigation indicates that the maximum vertical deformation for all different kinds of sandy soils accrued simultaneously. It was concluded that a soil's friction angle is affected by coarse-grained material. Accordingly, sandy soils with bigger particle size record a higher friction angle than soils containing small particles. Furthermore, a non-linear regression analysis was performed to determine the direct relationship between soil's friction angle and soil particle characteristics.

Determination of the Effect of Soil Particle Size Distribution on the Shear Behavior of Sand

“…These results seem to be consistent with other research (e.g. Rasti et al (2021)) which found that soils with bigger D 50 and uniformity coefficients have higher friction angles. However, soil 3 gives a lower friction angle than soil 2; a possible explanation for this might be that the average data used in this study.…”

“…It confirms clearly that shear strengths of samples with bigger D 50 are higher than mixtures with smaller ones; therefore, particle size distributions of sands play a significant role in the shear strength of samples [31]. It is encouraging to compare this figure with that found by Rasti et al (2021) [28], who also found that with increasing D 50 , the peak shear strength of samples increases. One unanticipated finding in Figure 5(b) is that sand 4 has friction angle of about 50°, however this magnitude is also reported in Bareither et al (2008) [32], Sladen et al (1986) [31].…”

“…butions of sands play a significant role in the shear strength of samples [31]. It is encouraging to compare this figure with that found by Rasti et al (2021) [28], who also found that with increasing D 50 , the peak shear strength of samples increases. One unanticipated finding in Fig.…”

“…50 are higher than mixtures with smaller ones; therefore, lay a significant role in the shear strength of samples [31]. It is ith that found by Rasti et al (2021) [28], who also found that with th of samples increases. One unanticipated finding in Figure 5(b) is ut 50°, however this magnitude is also reported in Bareither et al .…”

“…In another investigation, Hamidi et al (2012) [27] studied the shear strength and dilatancy of well-graded sand-gravel mixtures by conducting 27 large-scale direct shear tests and reported that the particle size distribution and D 50 of the tested soils significantly affect their shear strength. In a comprehensive study of the impact of D 50 on the shear behavior of soils, Rasti et al (2021) [28] performed a series of direct shear tests on four different sands and found that the D 50 of soils affects their critical friction angle.…”