Seismic Performance of Column Splices Tested at nees@berkeley
NEES research aims to provide practicing engineers a less expensive yet seismically sound method for welding steel building columns.
Recent tests at the nees@berkeley lab by UC Davis Professor Amit Kanvinde and graduate student Sean Shaw have been investigating the earthquake performance of steel building column splices. (View video from the NEEShub.) The building code currently requires that the abutment connection of two column segments, called a splice, be joined by a full penetration weld. This research is studying if partial penetration welds, which are cheaper and easier to construct, could perform sufficiently under earthquake shaking.
Column splices are used in all types of steel framing systems for several reasons. The most prominent of these reasons include the impracticality of transporting very long rolled sections to the construction site, OSHA overhead height limits on unfastened steel framing, and to implement cost savings. Research in the area of steel column splices occurred prior to the Northridge earthquake of 1994, and suggested that partial joint penetration (PJP) welds were prone to brittle failure. Since the Northridge quakes, weld quality has improved measurably and the objective of the project is to determine the feasibility of using PJP welds in modern steel special moment resisting frame (SMRF) buildings.
Five full-scale steel columns were tested using the unique 4 million pound press in the nees@berkeley lab to determine if PJP weld splice details could still achieve adequate performance under seismic loading while also reducing the construction costs and improving the constructability of steel SMRF buildings. These steel columns were W14 and W24 sections with sizes that could be used in buildings ranging from 4 – 20 stories.
A filmed interview with the UC Davis researchers has been overlaid with test footage from several of the steel column tests, and is now available for viewing on PEER’s YouTube channel and the NEEShub.
These experimental research tests at nees@berkeley are part a project titled "Seismic Performance of Column Splices" funded by the American Institute of Steel Construction (AISC) and the National Science Foundation, shared-use award #0825155.
More information can be found at the nees@berkeley website: http://nees.berkeley.edu/Projects/