As part of the commissioning of the Union-Pearson Express (UPX), vibration measurements were undertaken to confirm that the first mode of vertical vibration of the new 3.3 km elevated spur under dynamic loading (train pass-bys) occurred at frequencies of 3.5 Hz or higher. Vibration levels were measured during pass-bys of the UPX Diesel Multiple Units (DMU).
Substantial vibration monitoring equipment was required to measure vibration levels along the elevated structure. Instrumentation included 6 digital signal analyzers, 11 sensors, and approximately 2.4 kilometers of cabling.
Based on the monitoring data and subsequent analysis, the first mode of vertical vibration was confirmed to be higher than 3.5 Hz at the measurement locations. As such, it was concluded that the design and construction of the elevated structure met the above-noted requirement. Thus, train induced vibration on the elevated structure did not pose an issue neither on the structure itself, nor the comfort of the train passengers.
LEA engineer Felipe Vernaza completed work on the project while employed with a previous firm.