FORMULATION AND APPLICATION OF 3D ANCHOR BOLT ELEMENTS

A three dimensional anchor bolt element, permitting axial shear sliding at the bolt/grout interface,is developed in this paper. In this model the deformation distributions of the bolt are assumed to be linear and constant in the axial and radial directions respectively.Theoretical solution of the axisymmetric body is used to describe the axial displacement distribution of the grout. The normal Stresses transferred by the Steel bar and the shear stresses due to different axial movements between the bar and the grout, as well as the transverse shear stresses from the lateral movements on the grout-rock border, are major stress components described in the element. The edal sliding behaviour is sedated by evaluating the residual forces and then emploied the Newton-Raphson iteration scheme. The model is then used to sedate rockbolts in the analyses of pull-out tests. As an application example, an embankment with anchor bolts is investigated and the results are compared with a computation about rockbolts. The calculations illustrate the capabilihes of the element.