北京平原区黄庄—高丽营断裂北段结构特征及活动特点研究

黄庄—高丽营断裂是横穿北京市城区的一条规模较大的隐伏深大活动断裂,是北京凹陷和西山隆起的分界构造。本次研究工作区选在黄庄—高丽营断裂北段昌平未来科技城一带,对目标断裂先后开展了地震勘探、高密度电阻率法勘探以及槽探3种方法组合对其结构与活动性进行综合分析研究,查明了目标断裂的结构及其活动性。研究表明,黄庄—高丽营断裂由主断裂和次级断裂组成的断裂带,断裂带内次级断层也较为发育。断裂带在基岩中表现为阶梯状断层,向上延伸至第四系内部,形成"Y"字形断层组合。该断裂在全新世以来断裂活动明显,物探解译结果的上断点以及探槽中的现象均已达到地表。由此可见,本次工作所采用的3种物探方法组合,对探测城市隐伏断裂并探究其活动性,具有明显的效果,对减轻城市地震灾害实际应用评估具有十分重要的意义。

A study of structure and activity characteristics of the northern segment of Huangzhuang-Gaoliying fault in Beijing plain area

Huangzhuang-Gaoliying fault is a relatively large buried active fault across Beijing urban area. It is the tectonic belt of Beijing depression and Xishan uplift. The study area is located in the Future Science and Technology City in Changping. In this paper, the authors analyzed the structure and activity of the fault with the methods of shallow seismic exploration, high density resistivity method and trench profile. The results show that Huangzhuang-Gaoliyang fault is a fault zone that consists of the major fault and secondary faults. The fault belt in bedrock is mainly manifested as step fault and extends up to Quaternary, being a "Y" fault combination. Research shows that this fault has been strongly active since Holocene. Thus, the combination of three methods of shallow seismic exploration, high-density electrical and trenches is significant for detecting the buried fault in the city and exploring its activity, and it is also very important in applying practical assessment to reducing urban seismic hazard.