Evolution of Shear Band in Plane Strain Compression of Naturally Structured Clay with a High Sensitivity

Abstract

The formation of the shear band is associated with the failure of soil. However, there has been relatively little investigation on the evolution of shear bands in naturally structured clay with a high sensitivity. In this study, undrained plane strain compression tests, digital image correlation (DIC) analyses, and scanning electron microscopy (SEM) tests were performed to investigate the characteristics of shear bands in naturally structured clay. The basic mechanical properties and stress–strain relationships show that naturally structured clay exhibits a strong structure and high sensitivity. Compared with plane strain compression tests under low confining pressure, more localized shear bands emerge in the specimens during the tests under high confining pressures; however, when the specimens fail, only one shear band is fully developed, and the local deformation in the developed shear band is much larger than those in other localized shear bands. Moreover, the local stress–strain relationships inside and outside the shear band show distinct discrepancies. The SEM results show distinct micro-structures of clays inside and outside the shear band, which are caused by the development of the shear band. The findings in this work provide new insight into the failure of structured clay.

Assessment of Spatio-Temporal Kinematic Phenomena Observed along the Boundary of Triaxial Sand Specimens

“…Both figures indicate that the shear band only developed at a very late stage (axial strain 7.0%-9.0%). This agrees well with the findings in Liu et al [38] that localization increases with higher confining pressures under the plane strain condition. The plot of gradient along ρ axis F 11 (Figure 15) shows that the middle expansion started from an axial strain of 1.0%-3.0%.…”

Impact on slopes with development of shear band

“…The result concluded that the orientation of shear band completely depend on characteristics behavior of granular soil under the sample is subjected. Liu et al (2022) [13] performed three methods compression test, digital image correlation and scanning electron microscopy to study the development of shear band in sensitive soil under low to high confining pressure. It was observed that a large number of shear band emerges at a high confining pressure, which changes the internal properties of soil.…”