Abstract: Multi-disk anchor rod is a newly developed anchoring structure, which has excellent engineering characteristics compared with ordinary anchor rod. On the basis of the laboratory model test research of the multi-disk anchor, a theoretical calculation formula for the ultimate bearing capacity of the multi-disk anchor is deduced through the limit equilibrium theory. It’s validity is verified by the correspondence between the calculation result and the measured data. To further grasp the load transfer characteristics of the multi-disk anchor, an on-site slope anchoring prototype test is carried out. The data obtained from the on-site multi-disk anchor pull-out test are used to study the influence of the diameter of support disks, the spacing of support disks and the number of support disks on the ultimate bearing capacity and deformation control ability of multi-disk anchors. The test results show that in silty clay, when the distance between the support disks is greater than or equal to 4 times the diameter of the support disks, it can be considered that each support disk can work independently, giving full play to the bearing capacity of the multi-disk anchor; under the same conditions, compared with ordinary bolts, as the disk diameter increases from 300 mm to 500 mm and the number of disks increases from 1 to 3, the pull-out capacity of the multi-disk anchor increases significantly, and its deformation control ability is also greatly enhanced. The test results also show that the axial force transmission curve of the multi-disk anchor rod has a sudden change at the position of the support disk, presenting a steep drop, which fully reflects the contribution of the support disk in the uplift resistance. The research results have laid a good theoretical foundation for the engineering application of multi-disk anchor rods.

Key words: multi-disk anchor rod, ultimate bearing capacity, pull-out tests, load transfer, prototype test