Strengthening lightweight long-span timber floors: A study on vibration performance and human perception

Floor vibration is a common serviceability issue in low-rise commercial buildings across Australia with lightweight long-span timber floors (LSTFs). In the absence of validated dynamic properties, calibrated numerical models, analytical reliable methods for predicting vibration responses and sufficient studies on human perception of vibration in LSTFs, developing an efficient design becomes challenging. This study aims to provide insights into these unknowns for a simply supported 8-meter LSTF comprised of steel-wood timber truss (SWTT) joists with a particleboard slab. The research experimentally measures static deflection, natural frequencies, and mode shapes of both the SWTT and the LSTF, and uses these results to validate the numerical models. Responses to footfall excitations of the LSTF, both with and without strengthening using strongbacks, are measured through comprehensive walking tests and surveys of participants. The experimental measurements and survey results are compared with predictions from existing international guidelines recommended for designing floors to resist footfall-induced vibrations. It is demonstrated that the inclusion of strongbacks is an effective method for mitigating excessive vibrations, both from the participants’ perspective and in terms of standard compliance. The correlations between participant survey results obtained through virtual reality (VR) technology and the comfort criteria recommended in international guidelines are highlighted in the discussion. • Experimental and numerical analysis were performed to assess the vibration response of 8 m floor system to walking excitations. • Strongbacks improve stiffness by 276 % compared to unreinforced floors. • Strongbacks increase fundamental frequency by 80 % and eliminate torsional vibration modes. • Simple design methods for floor vibration often inaccurately predict floor acceptability. • Human perception of vibrations significantly improves with strongbacks.