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DRIVE-BY RESONANT BRIDGE DETECTION METHOD USING TWO TRACK IRREGULARITIES MEASURED ON THE FIRST AND LAST VEHICLES OF A TRAIN

. The resonance occurring when the excitation frequency of a running train coincides with the frequency of a bridge may considerably affect the safety and comfort of high-speed railway bridges. In Japan, train speed limits have been introduced in bridges operating for over 20 years because the resonance with their frequency has deteriorated. Their detection and mon-itoring by comprehensive and high-frequency measurements without the need to install sensors are important on many railway bridges. This study proposes a novel and efficient drive-by resonant bridge detection method using two track irregularity measurement devices that are al-ready installed on some commercial high-speed trains. The proposed method enables the estimation of the resonance-induced bridge amplified response by comparing the two track irregularities measured on the first and last train vehicles. The simulation results confirm that the amplified bridge vibration between the passage of the last and first vehicles is accurately detected by the proposed method. In the field tests, the proposed method is applied to two track irregularities measured on the first and last vehicles of a train. The amplified bridge vibration of the resonant bridges validated by in-situ measurements is then detected using the proposed drive-by method.