Abstract:
The influence surface coefficient for living loads,
K, is the key parameter for converting an actual load measurement into an Equivalent Uniformly Distributed Load (EUDL), following the principle of structural effect consistency. The existing calculation methods, designed exclusively for single-span and simplified beam-slab structures, yield unreasonable
K values when directly applied to continuous structures. However, employing a checkerboard pattern to approximate living load variations introduces an inherent conflict: it combines a stochastic load model with a deterministic load arrangement. This approach can also lead to unrealistic extreme load effects. To address this issue, this study adopts a probabilistic model to capture the stochastic nature of a living load across adjacent spans and employs Equivalent Patterned Load (EPL) to mitigate the overestimation of
K values. This study establishes a parametric finite element model for a typical continuous beam-slab structure and determines the
K values through a multi-factor analysis. The recommended coefficients are:
K1=1.0 (inter-story),
K2=1.0 (inter-span). The intra-span coefficient
K3 varies with the structural effect: 2.8 (Mid-span moment of the beam), 3.5 (Support moment), 2.0 (Deflection at the mid-span of the slab), and 2.0 (Axial force in the column).