天津Z2线地铁运营对沿线地面振动的影响分析

天津滨海新区Z2线为新型地铁线路,有着列车运行速度快、发车频次高等特点,其地铁运营时速最高可达120km,而中国现阶段城市中运行的普通地铁列车时速一般在60～80km。高速地铁荷载与普通列车荷载相比,有着频率高、幅值大的特点,所造成的环境振动规律也有所不同。以天津市Z2地铁线一期工程作为实例,依托实际工程数据,利用大型通用有限元软件ABAQUS建立隧道–土层三维有限元模型,采用动力隐式分析模拟地基土高速移动地铁列车荷载下的地表振动强度衰减规律,比较不同盾构隧道埋深、不同地铁列车行车速度以及不同隧道上覆土层性质工况下的地表振动变化规律,并结合相关城市环境振动评估标准,对地铁造成的环境振动进行评价,初步得到了地铁线路环境振动防护距离随以上三种因素的变化规律。研究结论可为今后高速地铁线路工程建设选线以及运营沿线振动预测、地铁沿线规划提供一定指导。

Influences of metro operation on ground vibration along Tianjin Z2 line

The Z2 metro line in Tianjin Binhai New Area is a new type of metro line. It has the characteristics of fast train operation and high frequency of departure. Its maximum speed of metro operation can reach 120 km per hour. At present, the speed of ordinary metro trains running in cities in China is generally 60~80 km per hour. Compared with the ordinary train load, the load of high-speed metro train has the characteristics of high frequency and large amplitude, and the pattern of environmental vibration is also different. Taking the first phase of Tianjin Z2 metro line as an example, and relying on the actual engineering data, a three-dimensional finite element model for rail track-tunnel-soil is established by using ABAQUS, a large-scale general finite element software. The dynamic implicit analysis is used to simulate the attenuation pattern of ground vibration intensity under the load of high-speed moving subway train in foundation soil, and different shield tunnels are compared. The variation of ground vibration under different conditions of road burial depth, train speed and soil properties of tunnels is studied. Combined with the relevant evaluation criteria for urban environmental vibration, the environmental vibration caused by metro is evaluated. The variation of environmental vibration protection distance of metro lines with the above three factors is preliminarily obtained. The research conclusions can provide some guidance for the selection of high-speed metro line construction, vibration prediction along the operation line and planning along the metro line in the future.