Composite beam-column flush end plate/blind bolted joints subjected to low probability, high consequence loading

![CDATA[Current design of reinforced concrete and steel framed structures in Australia typically caters well for gravity loading, wind and seismic loading of a 500 year return period. However, there has been much discussion about whether structures should be designed for low probability, high consequence events such as a 2500 year return period earthquake. This paper investigates the effects of adopting higher earthquake level loading and based on the new 1 in 2500 year earthquake event approach, medium rise semi-continuous composite frames will be analysed to ensure the suitability of using the flush end plate/blind bolted connection system. Comparisons will also be made to determine any differences between designing to the low and high level event, and the differences between nominally pinned and semi-rigid connections will also be examined. The earthquake actions were determined using the new draft earthquake code DR0403. Considerable savings were apparent when moving from a pinned connection to a semi-rigid connection. Not only in terms of weight savings but more importantly the ability to reduce the floor-to-floor heights, which can considerably reduce the cost of services and façades. This can also result in more lettable floor space due to reduced column sizes and the possibility of adding another floor for the same total height compared with the pinned connection. Due to the great uncertainties in predicting earthquake actions in Australia, and the fact that the standard 1 in 500 year event is very minor and causes no damage to properly designed structures it is highly recommended that the higher earthquake loading level be given more emphasis in the future, to reduce the likelihood of building failures due to earthquakes.]]