法源寺文保区毗邻菜市口大街及地铁4号线,区域居民长期受到环境振动影响。本文在对地面及轨道交通影响下法源寺文保区区域振动情况进行现场测试的基础上,对区域振动特征及振动超标原因进行了分析。结果表明:(1)法源寺文保区振动超标(67 dB)区域呈“双驼峰”形式,区域振动超标范围大,主要分布在菜市口大街非机动车道西侧40 m的区域;(2)超标原因主要为,地面及轨道交通量大,两者叠加导致振源强度高,振源距小导致振动衰减程度低,区域整体建筑基础薄弱、隔振性差;(3)浏阳会馆位置为典型的“振动放大区”,振动放大区位置为振中距1.5~3.0倍隧道埋设,这现有研究中地铁振动引起的振动放大区位置(1.0~1.5倍隧道埋设)并不契合,主要原因为地表及交通造成的地表振动频率成分不同,两者的叠加效应明显,凸形地貌的存在改变了原来振动波的传播路径,并对折射波具有放大作用;(4)区域受振动影响最大(78.49 dB)的位置位于距离法源寺后街116 m(地铁里程K6+270)的E4测点位置,主要原因为测试时该位置地铁4号线左右线隧道存在列车交会,地面交通及双地铁列车运营造成的地表振动不断叠加,最终导致该区域振动的加强。

Fayuan Temple historic reservation is adjacent to Caishikou Street and Metro Line 4, the residents of which place are affected by environmental vibration for a long time. Based on the in-situ vibration measurements, regional vibration characteristics and reason analysis on abnormal vibration are further studied and analyzed, which are caused by ground and subway traffic. Results show that: (1) The region that is overrun the control criterion of 67 dB shows a double-peaks configuration and is mainly distributed between main street and 40 m west of Caishikou Street. (2) The masonry structure's poor foundations, the short distance between vibration sources and residence community and the superposition of ground and subway traffic are the main reasons of large exceeding-standard area. (3) Liuyang Guild Hall is a characteristic region called the local amplification region (LAR). LAR of Liuyang Guild Hall appears with a distance of about 1.5~3.0 burial depth from the epicenter, which is different from other peoples. The dominating vibration frequency at surface mass point caused by ground traffic differs from that caused by subway traffic, the superposition of those should cause the new vibration laws of the ground particles. Meanwhile the protruding topography can change the propagation path of vibration waves and amplify the velocity of refraction waves. (4) The measuring points of E4 is affected most, which is 116 m away from Fayuan Temple Back Street. That is because there is two trains passing at their tunnels at E4, which leads to the vibration from subway traffic is strengthened. Then the superposition of ground and subway traffic can directly cause that the area of E4 is the most influential place.