数值分析地铁列车振动对周边环境的影响

H. XIA∗ , Y. M. CAO and N. ZHANG School of Civil Engineering & Architecture Beijing Jiaotong University, Beijing 100044, China ∗hxia@ Received 15 June 2006 Accepted 4 September 2006 A finite element approach is extended to study the ground vibrations induced by metro trains and their propagation properties. Two dynamic interaction models are established: the two-dimensional train-track interaction model, which provides the excitation loads of moving trains onto the tunnel structure, and the three-dimensional track-tunnelground interaction model, by which the propagation properties of ground accelerations and velocities are analyzed. The results show that there exists a vibration amplifying area in certain distance away from the tunnel center, and the dominant frequencies of the ground vibration concentrate in a certain range. Buildings located in that area with their natural frequencies falling in the specific frequency range will be sensitive to the ground vibrations induced by metro trains. Keywords : Metro train; tunnel; track; dynamic interaction; vibration; ground; environment.
International Journal of Structural Stability and Dynamics Vol. 7, No. 1 (2007) 151–166 c World Scientific Publishing Company
NUMERICAL ANALYSIS OF VIBRATION EFFECTS OF METRO TRAINS ON SURROUNDING ENVIRONMENT

1. Introduction With the growing concentration of population in metropolitan areas, the influence of train-induced vibrations on the environment has received great attention from the residents, and is now regarded as one of the seven main environmental problems in the world. In recent years, the requirement of considering the environmental influence in planning and designing traffic systems has become an essential issue. In the past, the cities were small and the buildings were relatively sparse, thus trafficinduced vibration was not considered as a serious environmental problem. While at present, with the rapid growth of modern large cities, the metro lines, urban railways and elevated traffic roads have gradually formed a multi-dimensional traffic system, extending and intruding from the underground, ground and overhead into the crowded residential areas, commercial centers and even cultural and high-tech research zones.1,2 At the same time, the traffic flows are getting more intense, traffic loads becoming heavier, and traffic vehicles running faster. These cause the influences of traffic-induced vibrations on the environment to be more and more serious
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than ever. According to the investigations conducted by organizations of several countries, traffic-induced environmental vibration receives nearly the most public complaints, second only to those from factories and construction sites.2 In fact, the factories can be built or moved away from the residential areas, and the vibrations of construction sites occur only during the period of construction. However, trafficinduced vibrations often occur around the most busy areas of the city, day and night, and thus have long-term influences on the residents or people working there, which can hardly be avoided. On the other hand, with the raise of living standard, the requirement of the people on the environmental quality is getting stricter. The environmental vibrations that have been tolerated in the past are increasingly regarded as a nuisance these days. Therefore, the influences of traffic-induced vibrations on the living and working environments of people have aroused the attention of the city administrators and researchers3–5 and numerous investigations have been conducted.6–22 Yang, Hung and Chang6 established a 2.5D finite/infinite element model to consider the load-moving effect of the train in the direction normal to the two-dimensional profile of the soil, by which they obtained three-dimensional responses for the soils using plane elements, and studied the transmissibility of soils for vibrations induced by trains moving at different speeds. Ju and Lin7 adopted the three-dimensional finite element method to simulate the soil vibrations under the train speed below and over the Rayleigh speed of the surrounding soil, and studied two vibration isolation schemes including the soil improvement around the railway and the concrete slab constructed between the rails and soil. In addition, Yoshioka,8 Krylov,9 Degrande and Lombaert,10 Madshus, Kaynia and Bessason,11,12 Yang,13 and Takemiya14 studied the ground vibrations induced by high-speed trains through theoretical analysis, numerical simulations and field experiments respectively. The characteristics of traffic-induced vibrations, such as the intensity, frequency, duration, distance between the vibration source and the receivers, their effects on the routine life and the physical and psychological health of the residents, their influences on the normal operation of precise instruments and manufacture of high-tech products, and their damages to building structures, etc. were studied by the abovementioned researchers and some others including Hanazato,15 Jones,16 and Xia and Cao.1,17,18 In metro systems, the vibrations induced by the train running underneath or close to buildings may become considerably perceptible. There have been several reports about the public complaints against this problem in Beijing and some other cities.1,2,19–22 A double railway tunnel is built underneath the city of Antwerp in the European High-Speed Train Network, where the nearest distance between the foundations of the houses and the top of the tunnel is only 4 m. Schillemans19 studied the projected vibration levels on the rail, the tunnel invert, building foundations and upper floors of the buildings near this tunnel, and the control measures for reducing the impact of sound and vibration on the environment. Metrikine and Vrouwenvelder20 investigated the ground vibration induced by a high-speed train