Design Live Loads for Coherent Crowd Harmonic Movements

Excessive vibrations and deflections associated with human movements have recently become of great concern in modern structures. The recommended design values for human loading in the current U.S. building codes and standards were developed over half a century ago and are based on strength requirements alone. Recent investigations have led to load models for individuals and small groups of people using laboratory measurements on small‐ and medium‐size force platforms. The current research project is directed towards testing the group harmonic load model and recommendation of design values. We designed and built a floor system instrumented with strain gages and displacement transducers to measure dynamic loads due to large groups of people. The floor system is analyzed experimentally and analytically. The imposed dynamic forces are determined using both data from the displacement transducers and the strain gages. The measured group harmonic loads compare closely with the computer simulation model of our previous study. Based upon work presented, structural design live loads are suggested for crowd harmonic movements for both strength and serviceability criteria.