MECHANICAL PROPERTIES OF ROCK ANCHORS INSTALLED IN ROCK MASS MODELS WITH CRACKS

Abstract

 In rock anchors used to stabilize rock slopes, tensile failure can occur at the anchor’s fixed end during strong seismic events. To investigate the effect of this tensile failure on the mechanical properties of the anchors, we conducted anchor pull-out tests and centrifugal loading model experiments on anchor models that simulated the presence or absence of cracks. The rock mass was modeled and created by combining blocks of artificial soft rock, assuming that the boundaries between the blocks represented failure surfaces caused by tension. The results of the anchor pull-out tests indicated that the decrease in anchor force was mitigated by the effect of confining pressure and the interlocking of cracks. Furthermore, based on the results of anchor loads and various displacements measured in the centrifugal loading model experiments, we analyzed the relationship between anchor load and displacement and examined the dynamic mechanical properties of the anchor with and without cracks. Within the range that does not exceed the ultimate anchor force, no significant difference in dynamic deformation characteristics was observed due to the presence or absence of cracks.