Column buckling of structural bamboo

Abstract

Bamboo scaffolding is widely used in construction in the South East Asia, in particular, the Southern China and Hong Kong for many decades. However, bamboo scaffolds are generally erected by scaffolding practitioners based on their intuition and experiences without any structural design. In general, column buckling is considered to be one of the critical modes of failure in bamboo scaffolds, often leading to their overall collapse. This paper presents a research and development project for structural bamboo where the column buckling behaviour of two structural bamboo species, namely Bambusa pervariabilis (or Kao Jue) and Phyllostachys pubescens (or Mao Jue) were investigated. A total of 72 column buckling tests with bamboo culms of typical dimensions and properties were executed to study the column buckling behaviour of structural bamboo. Furthermore, a limit state design method against column buckling of structural bamboo based on modified slenderness was established and carefully calibrated against test data. It is shown that for Kao Jue, the average model factors of the proposed design method are 1.63 and 1.86 for natural and wet conditions, respectively. Similarly, the average model factors of the proposed design method for Mao Jue are 1.48 and 1.67 for natural and wet conditions, respectively. Consequently, the proposed design method is shown to be adequate. With the availability of design data on the dimensions and the mechanical properties of structural bamboo together with the proposed column buckling design rule, structural engineers are encouraged to take the advantage offered by bamboo to build light and strong bamboo structures to achieve enhanced economy and buildability.