Experimental research on tensile strength of gravelly soil under different gravel contents

The tensile strength of gravelly soil is one of the important indexes for resisting the cracking of earth core rockfill dams. Based on the self-developed uniaxial tensile test mould, a series of uniaxial tensile tests are carried out on the gravel soil with different gravel contents. Within the range of test parameters, the tensile strength of gravelly soil decreases with the increasing water content and increases with the increase of dry density. The relationship of tensile strength versus the optimum water content and the maximum dry density is presented, respectively. For the gravelly soil with the optimum water content and maximum dry density, as the gravel content increases from 0% to 50%, the tensile strength of specimens decreases from 122.6 kPa to 49.8 kPa linearly. The peak tensile strain and ultimate tensile strain both decrease with the increase of the gravel content. From the fracture energy analysis, it is found that the tensile capacity of gravelly soil decreases slightly with the increase of the gravel content. In the case that the specimens with the maximum dry density and the water content higher than the optimum water content, the comprehensive tensile capacity of the specimens is the strongest. The relevant test results can provide support for the anti-crack design of high earth and rockfill dams.