Steel-to-concrete joints with large anchor plates under shear loading

In industry and plant engineering especially, high flexibility is required at joints between steel and concrete. According to current standards, the maximum number of fasteners is limited to an arrangement of 3 × 3 anchors on an anchor plate. The load-carrying behaviour of large anchor plates under tension, shear and restraining forces was investigated within the scope of the research project “Large Anchor Plates with Headed Studs for Highly Stressed Constructions in Industry and Plant Engineering”. This paper describes the research results obtained at the University of Stuttgart for large anchor plates under shear loading. Findings for large anchor plates under tension and restraining forces are given in [20], which were mainly investigated at the University of Kaiserslautern.
The shear behaviour and distribution of forces within the anchor plate are crucial issues in the development of a design concept for steel-to-concrete joints with large anchor plates. The influence of different parameters, such as the dimensions of the anchor plate, the embedment depth of the headed studs or the eccentricity of the shear force, have been studied in several test series. Supplementary reinforcement was placed close to the headed studs in tension to strengthen the load-carrying capacity of the joint. The distribution of the shear forces has been assessed by means of numerical investigations together with the influence of further parameters such as concrete strength and reinforcement ratio. With regard to the load distribution within the anchor plate, elastic and plastic design approaches have been taken into account.
Based on these studies, a suitable design model has been developed for steel-to-concrete joints with large anchor plates and a higher number of fasteners than originally permitted. Owing to the consideration of supplementary reinforcement, in addition to the plastic design approach, an alternative economical solution is given which links the component method according to EN 1993-1-8 to the fastener technique according to EN 1992-4.