Design strengths of bamboo based on reliability analysis

To reasonably determine the design strengths of bamboo, in this work, the tensile strength parallel to particles, compressive strength parallel to particles, tensile strength perpendicular to particles, and compressive strength perpendicular to particles of bamboo were systematically investigated. The tensile strength parallel to the grain of the bamboo material was the highest, and it reached the minimum when perpendicular to the grain. The influence of the functional form of the probability distribution and data points for fitting on the reliability was evaluated by the first and second-moment checking point method. It was recommended to use the fitting results of the first 15% strength data and the 2-P-Weibull probability distribution model to determine the design values of the bamboo strength. On the basis of reliability analysis, the variation rule of reliability index and resistance coefficient of bamboo under different load combination types and load-effect ratios was calculated. The optimum partial resistance coefficient of the bamboo was determined by minimising the sum of squares of error, and the design strength of the bamboo was determined accordingly.