Resonance and cancellation phenomena caused by equidistant moving loadings in a periodic structure — A pile-supported periodic viaduct

• Resonance and cancellation phenomena in the periodic viaduct subjected to multiple equidistant moving loadings (MEML) are found for the first time.
• The conditions for the occurrence of the resonance and cancellation phenomena in the periodic viaduct subjected to MEML are proposed.
• Numerical simulations to demonstrate the resonance and cancellation phenomena occurring in the periodic viaduct are conducted.

In this paper, the resonance and cancellation phenomena occurring in a periodic structure-- a pile-supported periodic viaduct subjected to multiple equidistant moving loadings (MEML) are investigated. For this purpose, the representation for the dynamic response of the periodic viaduct to a single moving loading (SML) is introduced first. In order to take account of the pile-soil-structure interaction when evaluating the response of the periodic viaduct to a SML, a wavenumber domain boundary element method (WDBEM) model for the pile-row-soil system is employed to determine the compliances of the piles. By superposing the responses of the viaduct to all SMLs constituting the MEML, the representation for the dynamic response of the periodic viaduct to the MEML is obtained. With the representation for the MEML response of the viaduct, the resonance and cancellation conditions for the viaduct are derived. For the high speed MEML, when the time interval between two neighboring moving loadings is equal to the integer or half-integer multiples of the period of one of the dominant resonance peaks of the corresponding SML response of the viaduct, resonance or cancellation occurs. The predicted resonance and cancellation phenomena are confirmed by the numerical results presented in this paper.