Prediction of building vibration induced by metro trains running in a curved tunnel

Abstract

Curved metro lines currently account for a significant proportion of total route mileage. However, the existing prediction model of environmental vibration only considered the vibration induced by trains running in a straight tunnel. In the present study, a numerical model was proposed to predict the environmental vibration induced by trains running in a curved tunnel. The model was divided into two parts: a train–track coupled model and a tunnel–soil–building finite element model. In the first part, a novel three-dimensional train–curved track coupled model was established and solved in the frequency domain based on the periodic theory. Both vertical and horizontal train loads were calculated by this model. Then, an in situ measurement was performed in the curved tunnel of an operating metro line, and the tunnel vibration responses were obtained and used to calibrate the train–track model. Finally, a case study was selected from Beijing metro line 16, where it is needed to predict and evaluate the environmental impact of vibration from a curved metro line being planned for construction beneath an office building. A three-dimensional tunnel–soil–building finite element model was built, and the building vibrations in vertical and horizontal directions were predicted. The results show that the floor vibrations have peak values of approximately 5.29 and 27.8 Hz, which are exacerbated by the building local mode and the spacing of the rail supports. Below the third floor, the vertical vibration response exceeded the vibration control limit recommended by Chinese national standards. Track solutions for vibration control must be implemented to mitigate the environmental vibrations.

Sources of variability in metro train-induced vibration

“…To predict and reduce railway-induced vibration, evaluation and prediction methods have developed rapidly in recent years 3,4 . These include empirical, analytical, and numerical methods.…”

Vibration transmissions and predictions within low-rise buildings above throat area in the metro depot

“…Massive construction of urban railway transit systems is a tendency in accordance with the fast-developing pace of megacities. Forty cities in mainland China have put urban rail transit systems into service by the end of 2019, including more than 300 depots and parking lots (Ma et al, 2021). As for a metro system, the metro depots are basic ancillary facilities and used for storing, cleaning, maintaining, and testing metro trains (Ministry of Housing and Urban-Rural Development of the People’s Republic of China, 2013).…”

“…Ground and building vibration differences caused by the straight track and curved track are characterized. There is research on predictions of curved trackinduced vibrations, such as that by Ma et al, (2021). However, tracks in the throat area of metro depots are more densely located where the complex tracksoiltrack dynamic interaction effect may not be ignored.…”

Evaluation Method of the Vibration Reduction Effect Considering the Real Load- and Frequency-Dependent Stiffness of Slab-Track Mats

“…For instance, 46 cities in China have constructed 7142 km of URT lines, and the fastest operating speed has reached 160 km/h. However, the high density rail transit network and the fast operating speed inevitably cause more obvious environmental vibrations and noise problems [ 1 ]. A common measure to decrease noise emissions and vibrations involves the installation of resilient elements in the railway track [ 2 , 3 ], such as rail pads [ 4 ], under-sleeper pads (USM) [ 5 ], under-ballast mats (UBM) [ 6 ], crumb rubber [ 7 ], and slab-track mats (STMs) [ 8 , 9 , 10 ].…”