Visualization technology and application analysis of shearing tests for different kinds of soil

WANG Zihan, GE Hao, JING Xiaokun, XIAO Chengzhi, and HUANG Da School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, P. R. China A bstract: In order to study the application of visualization technology in shear tests of soil and the deformation mechanism of shear band, shearing tests on different kinds of soil are carried out by using the visualization shear equipment. Combining with digital image deformation measurement technology, the displacement images of soil specimens are obtained in shear processes. The deformation characteristics of sand, clay and gravel samples in shearing tests are studied. The results show that the shear bands of sand samples are the "fish-shaped" areas between the upper and lower shear surfaces when shearing failure occurs. The thicknesses of shear bands increase at first then decrease with the increasing shear displacement. The clay specimens are mainly destroyed along the horizontal planes between the upper and the lower shear boxes. And there is no obvious secondary shear surface. The shear bands of gravel samples are mainly concentrated in the "arched" areas between the primary and secondary shear surfaces in upper shearing boxes. The stresses on "arched" secondary shear surfaces are greater than that on horizontal primary shear surfaces, and the strength indexes are basically consistent. This research can provide scientific methodology for developing mechanism of shear zone of soil and the establishment of constitutive models.