Experimental Buckling Capacity of Multiple-Culm Bamboo Columns

This paper presents the experimental results of an on-going study investigating the buckling capacity of single-culm and multiple-culm bamboo column elements. Four single-culm columns of species Bambusa Stenostachya were tested to obtain single-culm column capacities as well as control tests to determine the behaviour of short-doweled end-conditions. Three multiple-culm columns were then tested in order to investigate the ultimate capacity and buckling behaviour of these elements. Specifically of interest wasthe effect of bamboo stitching on improving column behaviour in the bamboo culms. Experimental values were compared with theoretical predictions for buckling capacity using the Euler equation. The behaviour of multiple-culm columns was shown to exhibit load redistribution and to mimic the sum of individual culm capacities rather than composite column behaviour. Stitching was shown to be beneficial in enforcing column geometry yet detrimental through introduction of lateral loading to culms. Finally, the apparent effective length factor K was shown to be closer to K=1 than to the value obtained from control tests of the designed end condition.