This paper discusses the derivation of a set of dynamic load factors for calculation of walking response on the basis of measurements made during a biomechanics research carried out with young adults. Firstly, a quite large number of experimental data on single footstep force were collected. The single footstep forces were then superimposed to generate the force time history for a continuous walk. This was followed by the transformation of the resultant force to the frequency domain from which the dynamic load factors for the first ten harmonics of a pacing rate can be extracted. A statistical analysis was employed on the dynamic load factors to acquire their design values in terms of the 90-th or 95-th percentile. The waking force function recommended by various design guides and that developed in the paper were then used in a comprehensive finite element model to predict the vibration level of a building floor. Current design guides on floor vibration normally suggest using four harmonics in the walking force whereas load factors for ten harmonics were developed in this paper. The acceleration response of the floor was found to increase by 5-33% when walking harmonics beyond the fourth harmonic were considered. The inclusion of higher harmonics would therefore lead to a more conservative estimation of the floor response.

The paper presents a comparison of testing methods and post processing techniques for modal properties of a fully furnished chipboard floor and an unfurnished prestressed concrete floor. A thorough modal testing required relocation of transducers among test setups to acquire multiple synchronous measurements of floor response due to heel drop excitation or shaker excitation. The comprehensive experimental data was processed by a specialised operational modal analysis software. On the other hand, a simple testing approach only required records of floor response at a single point due to heel drop. The measured response can be easily analyzed using simple procedures of structural dynamics. Whilst valuable information about the floor modal properties including the mode shapes was obtained using the sophisticated approach, the uncomplicated single-point heel drop test was found to provide reasonably accurate evaluation of natural frequencies and damping ratios for both of the test floors, which verifies the attractiveness of the simple technique. Based on experimental results, both of the floors would be considered as low-frequency floors by commonly used guidelines on human-induced floor vibrations. Furthermore, the effect of fit-out conditions and construction materials on the huge discrepancy between damping values of the two floors was also observed.

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