Study the prying effect on bolted base-plate connections

Abstract

The paper presents the details and results of an experimental study on bolted base-plate joints of industrial type steel building frames. The investigated joints are commonly used in industrial buildings.

The aim of the research was to determine the failure mode and load bearing capacity of the base-plate joints with different base-plate thicknesses and by different anchorage length. In the experimental programme 14 full scale specimens were tested and covered three different end-plate thicknesses. The steel grade of the test specimens was S355, the bolt diameter M20, whereas the bolt grade was 5.6. The tested joint arrangement was the same during the test series, with exception the base-plate thickness (tbp = 16 ~ 20 ~ 24 mm).

The specimens were investigated under pure bending conditions using a four-point-bending arrangement, in which the test specimens were changed. In all tests the typical displacements were measured by inductive transducers under the loads and in the cross-section of the tested joint. The bolt force distribution was registered by special load cells.

The measured data were presented and evaluated by momentbolt- row force and moment-deflection diagrams. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the pretensioning of the bolts on the behaviour of bolted joints and the evolving of the prying effect were analyzed.