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通海隧道区域构造发育规律及其发震机理研究

Study on Developmental Rule of Regional Structure and Earthquake Mechanism in Tonghai Tunnel

【作者】 李光慧

【导师】 何满潮;

【作者基本信息】 中国地质大学(北京) , 地质工程, 2007, 博士

【摘要】 通海隧道是云南国际铁路通道昆明至河口线上的特长隧道(全长10.302km),地处近南北向断裂带与北西向断裂带交汇区域,隧址紧邻1970年通海大地震震源区,地震灾害危险性极大。过去人们普遍认为隧道受周围岩土体约束,在地震时隧道随周围岩土体一起运动,地震对隧道的影响很小,因此,国内外对活动断层与隧道地震危险性的研究还处于起步阶段。随着地震对隧道安全危害的案例越来越多,人们已逐步意识到活动断裂与隧道抗震问题的研究已迫在眉睫。本文以通海隧道建设工程为依托,在搜集已有地震地质和地震活动等资料的基础上,采用区域地质测绘、深孔钻探和可控源音频大地电磁(CSAMT)物探测试等综合勘察手段进行通海隧道区域构造发育规律及发震机理研究。研究内容有:通海隧道区域深部活动性断裂分布规律和地球物理特征;通海隧道区域新构造特征、区域强震特征和区域活动性构造发育特征;通海隧道近场区主要活动性断裂特征、地震活动特征、区域地震活动性时空以及构造发震危险性;通海隧道区域震源分布、地震危险性和地震加速度分析。研究结果表明:通海隧道近场区地壳新构造运动有整体隆起与断块差异升降、断裂走滑运动与断块的隆起及坳陷和地震活动等特征;近场区断裂主要分为北西、北东、北北东向三组;近场区的全新世活动断裂和晚更新世活动断裂均以走滑活动为主要特征;近场区受历史地震影响非常严重,历史地震在近场区内的分布非常不均匀,隧址南北两段的地震活动差异非常大,南段在强度和频度上都远小于北段;工程场地所遭受的历史地震最大影响烈度达到X度。区域地震活动强度非常大且频度高,集群性特征显著,但分布极不均匀;现代中小地震活动的集群性和继承性非常明显;未来百年内区域地震活动水平与1900年以来的活动水平相当。查清了通海隧道穿越周沟断层(F4-1)、关营断层(F4)、通海断层(F11-2)、泥者断层(F11-3)和乌龙塘断层(F11-4)的空间分布及地质特征;采用活动断层抗震设防衬砌、增大隧道限界及在活动断裂带边缘及内部设置全环变形缝等措施,圆满解决了通海隧道穿越活动断层难题。实现了高烈度地震区隧道修建技术的重大突破,对类似条件的工程建设具有重要的指导意义。

【Abstract】 Tonghai tunnel, with a total length of 10.302km, is the longest on Kunming-Hekou of yunnan international railway now under construction. The tunnel goes through that the region of crossover faults with SN and NW direction, which is Tonghai earthquake focus in 1970, which would suffer significant damage with earthquake disaster in the future.In the past, people thought that tunnel was restricted by the surrounding rock and soil, when earthquake came, tunnel would move alone with rock and soil, which is slight damage. Therefore, the research of active fault and earthquake resistant design of tunnel is rare. Alone with increasing the event of earthquake disaster in tunnel, many people have considered that is urgent.On basis of the construction of Tonghai tunnel, as well as on the collecting data of seismo-geology and seismic record, the developmental rule of regional structure and earthquake mechanism in tonghai tunnel, are studied by means of regional geological investigation and survey, deep-hole drilling exploration, Controlled Source Audio-frequency Magnetotellurics et al. in tonghai tunnel. Research on the distribution rule of deep regional active faults, the geophysical features, the features of new structure and regional strong earthquake, the developmental features of regional active structures in tonghai region. Research on the features of main active faults , characteristic of earthquake, spatial-temporal distribution of regional seismicity, as well as analysis tectonic earthquake hazard, distribution of regional earthquake focus, earthquake hazard and earthquake acceleration in the near field of Tonghai tunnel.In the near field of Tonghai tunnel, the research results show the movement features of crust new structure, which are whole uplift, difference rise and fall of faults block, faults strike-slip, cave and uplift of faults block, earthquake et al.The main faults strike are NW and NE and NNE direction. The active faults are strike-slip faults in Holocene and late-Pleistocene.The field is influenced by historical earthquake seriously, which is unsymmetrical in the spatial-temporal distribution of earthquake. The difference of seismicity is obvious in the earthquake intensity and frequency, which is less serious in the part south than that of the part north of the railway. The maximal earthquake intensity is X degree on the site of the railway in history. The earthquake intensity is strong and the earthquake frequency is high. The features of clustering occurring is remarkable,but the spatial-temporal distribution of earthquake is unsymmetrical in the field. The features of the clustering and continuously occurring are obvious with modern moderate-slight earthquake. In the next one hundred years, the level of seismicity will be the same as in 1900s’. Research illustrates that the spatial distribution and geological features for Zhougou fault (F4-1), Guanying fault (F4), Tonghai fault (F11-2), Nizhe fault (F11-3) and Wulongtang fault (F11-4). The problem was solved in Tonghai tunnel by mean of Tunnel lining of anti-earthquake for active fault, to enlarge construction clearance of tunnel, to set deformation joint in boundary and inside of active fault zone. Thus, breakthrough has been achieved in the construction technology for tunnels under severe seismic zone, which has important guiding significance for future tunnels under similar geological conditions.

  • 【分类号】U452.1;P315.9
  • 【被引频次】1
  • 【下载频次】282
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