Size Effect on Tensile Properties of Compacted Clay Using Deep Beam Specimens

Abstract In this study, the size effect on the tensile properties of compacted clay was investigated by using deep beam specimens. The equation for calculating tensile strength considering the effect of specimen thickness was established based on the results of finite element analyses. By using deep beams, Brazilian discs, and three-point bending beams, the tensile strength of compacted clay was tested to verify the rationality of deep beam specimens. Furthermore, differences in the tensile properties of deep beams of different sizes (widths of 50, 75, 100, and 125 mm) were explored. The results showed a significant size dependence of the peak load and peak displacement. As the specimen size increased, the tensile strength of the soil exhibited a linearly decreasing trend, whereas the energy required for tensile damage gradually increased. The Bažant size effect model was used to predict the strengths of compacted clays, and a peak load prediction model that considers the structural parameters of the specimens was developed.