Measurement of flow-induced vibration in power plant coal silos

Results of full-scale experiments on large power plant coal silos are reported. One silo in a row of six was instrumented with strain gages, load cells and velocity transducers. Static loads, deflections, and strains were measured first to evaluate the stiffness of the system and the structural interaction between adjacent silos. Then dynamics loads, displacements, and strains were measured during a 12-hour cycle of normal coal-feeding operations. The effects of steady state vibrations and of vibrations induced by intermittent shocks due to irregularities in the flow were investigated. The loads and strains associated with the steady state vibrations were small. However, it was found that the shocks, which occurred at a rate of about 5 to 6 per minute, had load amplitudes of up to several hundred kips and dynamic load factors ranging from 0.72 when the silo was full to 1.11 when it was partially full.