Empirical Frequency Analysis of Bridge Deck Slabs

For the purpose of bridge design it is often convenient to know empirical relationships among various parameters such as natural frequencies, mode shapes, and impact factors under live loads. Availability of these empirical relationships would serve a useful purpose in commencing, checking, or finalizing results in dynamic analysis. It is the purpose of this note to present a formulation applicable to isotropic slab bridges and compare the results with those computed using other methods. After comparing the frequency parameters, it is believed that the empirical relationship derived can be successfully used for obtaining frequencies of vibrations sufficiently accurate for all practical design purposes.