Abstract
A new type of plane strain apparatus is developed to study the mechanical properties and shear band failure of soil, which possesses the advantages of flexible loading for lateral confining pressure and noncontact measurement and high measurement accuracy for surface deformation. In addition, the whole deformation procedure of the specimen can be recorded with images, which can be used to describe the development of strain localization and the shear band. It can be seen that the deformation process has three obvious stages, that is, the hardening stage, the softening stage, and the residual stage. The measured inclination angles of shear bands decrease as confining pressure or the mean size increases. In addition, it can be observed that the sand presents continuing growth of the unrecoverable plastic deformation inside the shear band and exhibits almost elastic deformation outside. From the detection results for local points in the specimen, the stress–strain relationships are different for different parts, and the sand sample behaves like an uneven structure instead of an even element, which means that the usual method of measuring the stress–strain relationship of the soil sample is only a macroscopic approximation.
Highlights
The phenomena of progressive failure feature of localized shear bands have attracted considerable attention in practical engineering, such as the slope sliding and the foundation instability in the geotechnical engineering
As the shear band failure is easy to trigger and to observe in plane strain state, the plane strain apparatus is developed to serve for the study of the mechanism of the shear band failure in laboratory
The deformation distribution over the entire surface of the specimen is obtained by digital image measurements during plane strain test; the strain distribution is derived from the measured deformation
Summary
The phenomena of progressive failure feature of localized shear bands have attracted considerable attention in practical engineering, such as the slope sliding and the foundation instability in the geotechnical engineering. U v ð5Þ where (ex, ey, gxy) are horizontal strain, vertical strain, and shear strain, respectively; B is the strain– displacement transformation matrix, which can be obtained according to standard finite element analysis process In this way, the deformation distribution over the entire surface of the specimen is obtained by digital image measurements during plane strain test; the strain distribution is derived from the measured deformation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
