Experimental and analytical investigation on the dynamic characteristics of cross-laminated bamboo and timber (CLBT) floors

Cross-laminated bamboo and timber (CLBT) is a novel composite material combining glued laminated bamboo (glubam) with timber. So far, the dynamic performance of CLBT floors has remained largely unexplored. This study systematically investigates the vibration behavior of CLBT floors subjected to walking, running, and jumping via experimental tests and theoretical modeling, focusing on fundamental frequencies and accelerations. Key findings reveal that the glubam type has a negligible influence on natural frequencies (variation < 5%), whereas a reduction in span increases them by over 50%. An accurate analytical model, validated against experimental data (R² > 0.96), is also proposed to predict these vibration responses. Comparative analysis demonstrates that CLBT floors exhibit better vibration performance than comparable cross-laminated timber (CLT) floors, attributable to the advantageous composite effect. Crucially, a comprehensive parametric study found that strategic dimensional adjustments can significantly improve the vibration performance of CLBT floors. This finding was further validated through in-situ analyses of a CLBT floor in a multi-story bamboo structure. The predicted peak accelerations show good agreement with experimental measurements (relative errors within 20%), and the recorded in-situ values, ranging from 0.038 to 0.112 m/s², confirm that the floor's vibration performance remains within the perceptible but acceptable range under most service conditions.