三维交叠隧道列车运营对环境的振动影响

Vibration Effect on Surroundings Induced by Passing Trains in Spatial Overlapping Tunnels

北京站至北京西站地下直径线宣武门地段交叉穿行地铁2号线及4号线宣武门车站,以此复杂的空间三线交叠隧道为背景,对列车振动荷载下的动力响应进行研究。通过荷载数定法和解析公式法,分别计算既有地铁列车和直径线铁路列车的振动荷载曲线,并作为激励源作用于所建立的宣武门地段的动力有限元模型上,进行三维动力有限元数值模拟,通过有效地选取拾振点和振动参量,对其动力响应的特点及振动传播规律进行分析研究。结果表明,北京地下直径线宣武门地段的开通运营会增加邻近地铁结构的振动响应和附加动应力,对结构耐久性和正常使用有一定影响;地面点产生的振动速度较小,不会对地面结构造成损坏;地面点的垂向振级超过规范标准;考虑此地段振源复杂、结构重要,建议采取较高减振措施,不需特殊减振;动力响应随着离开振源的距离不同而呈有规律的变化,且在离开振源水平向一定距离内存在振动放大区。

The under-construction Diameter Line is an important underground line linking the two main railway stations in Beijing. The new line is in close proximity to the existing Metro Line 2 and Line 4, which overlaps Line 2 and crisscrosses Line 4 down the two Xuanwumen Stations. In this paper, the characteristics of vibrations and their transmission laws in the Xuanwumen stretch are presented. The three lines （including Line 2, Line 4 and the Diameter Line）. A complex three-di element （FE） model of this section is made to simulate the dynamic responses ground. The excitation loading of the Metro and railway trains are obtained using vibratio mension ns a are induced by the （3D） dynamic finite in the structures and on the the two simulated deterministic methods. The results show as follows. The optical method is effective to determine the receiver point and its parameters; commissioning of the Diameter Line will have some influence on vibration of the existing Metro structures; the additional dynamic stresses induced by passage of Metro and railway trains will have effects on the mechanical behavior of tunnel structures; the dynamic responses will vary regularly along with the horizontal and vertical distances from the vibration source, and a vibration amplifying area will come into existence within a certain distance in the horizontal direction; vibration mitigation in the Xunwumen stretch is needed to reduce the impacts. Vibration reduction measures are proposed.