Large airport hubs make transfers between aircraft, high-speed rail, subways and maglev trains easier. But when hotels and passenger overnight rooms sit above or close to rail infrastructure, train-induced vibration must be predicted before construction and controlled through suitable track measures.
A study published in Journal of Railway Science and Technology examined passenger overnight accommodation planned near Changsha Huanghua Airport Terminal 3. The hotel is supported over a subway line by structural columns, while a high-speed railway line intersects the subway line nearby. To assess vibration transmitted through the track, station, building and soil, the researchers built a two-step simulation framework.
"First, a train-track coupled vibration model calculated the dynamic forces generated at rail fasteners as subway and high-speed railway trains passed over the track," shares lead author Lidong Wang of Changsha University of Science & Technology. "Those forces were then applied to a detailed finite-element model of the track, station, hotel and surrounding soil."
This allowed the team to compare floor and column responses and evaluate acceleration, maximum Z-vibration level and one-third-octave frequency-band vibration levels.
"Airport hubs are becoming more compact, so designers need to understand rail-induced vibration before hotels and other sensitive spaces are built," says corresponding Yan Han, who hails from the same university. "Our framework links the train-track forces to the building and soil, helping identify where limits may be exceeded and which mitigation measures are likely to work."
Under single-train operation, floor responses were stronger than those of structural columns at the same floor, and vibration acceleration decreased on higher floors. A subway train at 80 km/h or a high-speed railway train at 300 km/h could make floor vibration perceptible.
"For the maximum Z-vibration indicator, only one floor point exceeded the daytime limit when a high-speed train ran at 300 km/h, whereas 23 points—about 16%—exceeded the nighttime limit when a subway train ran at 80 km/h," says Wang. "Most floor points also exceeded one-third-octave limits, with subway-related exceedances concentrated around 40 Hz and high-speed railway exceedances spanning roughly 40–80 Hz."
The team then tested a combined mitigation strategy: steel-spring floating slab track for the subway and vibration-damped track for the high-speed railway. "Under simultaneous operation of one subway train and one high-speed railway train, the measures kept floor acceleration below the human perception threshold and brought all evaluated vibration indicators within relevant standards," adds Han.
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Contact the author: Yan Han, School of Civil and Environmental Engineering, Changsha University of Science & Technology, Changsha, Hunan, China, cehanyan@csust.edu.cn
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Vibration assessment and mitigation for an over-track building in a large-scale transportation hub induced by subway and high-speed railway trains
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Wenbin Lu, Xianghong Yang, and Jiangying Wang are currently employed by Hunan No.6 Engineering Co.; Lidong Wang, Xinqiang Qing, Jingcheng Chen, and Ying Yang are currently employed by China Construction 5th Engineering Division Co.