Open AccessA new assessment approach for post-installed anchors used in seismic applications
Author(s) -
Erik Johannes Stehle,
Akanshu Sharma
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/615/1/012063
Subject(s) - bracing , structural engineering , frame (networking) , displacement (psychology) , engineering , connection (principal bundle) , seismic loading , range (aeronautics) , seismic analysis , computer science , brace , mechanical engineering , aerospace engineering , psychology , psychotherapist
Steel bracing has proven to be a very powerful method to improve the seismic behaviour of reinforced concrete frame structures. In general the steel braces are indirectly connected to the RC frame via additional steel frames that are in turn fixed to the RC frame using post-installed anchors or reinforcing bars. However, this method comes with several shortcomings including increased weight and a disruption of the buildings function during installation. Therefore new connection approaches were developed where the braces are directly connected to the RC frame. One of the most promising solutions is the connection by means of post-installed anchors to connect the bracing to the frame corners. Using this type of connection allows an effective and low invasive strengthening of the structure. In this case the performance of the retrofitted structure is highly dominated by the performance of the post-installed anchors, since the imposed seismic demands are rather high. Therefore it is deemed necessary to assess the anchor performance under seismic actions, especially their displacement behaviour in the post-peak range. The current guidelines for seismic qualification of anchors only provide a force-controlled assessment procedure which is valid for non-structural connections but is not sufficient to obtain the information required for the assessment of their seismic performance in structural applications. A new displacement-controlled approach for the assessment of post-installed anchors under seismic conditions is presented. This approach allows the evaluation of the complete load-displacement behaviour as well as the hysteretic response of the anchors even in the post-peak range. A comparison with existing force-controlled assessment procedures shows that this approach is more suitable for the assessment of anchors used in structural strengthening applications under seismic actions.