Plasticity of anchors in damaged by earthquake concrete base

Abstract

Most frequently used types of anchors were subjected to experimental studies to obtain valid data on post-installed anchors, such as mechanical anchors (wedge expansion anchors, undercut anchors); bonded anchors (with epoxy resin) and bent cast-in-place anchors. The authors studied the effect of an earthquake-induced damage (plastic deformation) of a concrete base and multi-cyclic dynamic loads, similar to seismic ones, on plasticity of anchors. Plastic phase deformation in case of reinforced concrete base was simulated as a system of cracks of different opening width. The results of the research show that increase in the width of the crack opening from 1.5 to 3.0 mm leads to a decrease in the values of the plasticity factors. Dynamic loading does not lead to a significant change in the plasticity factor related to static loading for all failure mechanisms, except for the bond failure. On the base of obtained results reduction factors of seismic loads may be determined for further calculation of anchor joints subjected to seismic impact.