【作者】 余成华；

【导师】 尚岳全；

【作者基本信息】 浙江大学 ， 防灾减灾工程及防护工程， 2010， 博士

【摘要】 北东向和北西向两组断裂是深圳市主要断裂,鉴定其活动性,判定它们是否为具有发生直下型破坏性地震能力的地震活动断层,评价其最大地震震级及地震危险性,对区域防震减灾、工程地质环境评价等方面具有重要的意义。通过分析区域地质构造背景、区域地球物理场特征、现代地壳运动特征、现代构造应力场特征、区域地球动力背景及地震活动性等地震构造环境,认为本研究区范围处于华南加里东褶皱系的粤北、粤东北-粤中拗陷带内,整个区域范围大面积分布花岗侵入巨大岩基体和一些中小岩体,主要包括晚更新世及全新世地层,区内重要的地震构造为北北西-北西向断裂构造。认为新构造运动以来,研究区总体上是继承了断块运动特征,处于隆升状态,深部构造环境的差异性不大,中强地震主要分布于海域,历史地震活动强度相对较低,对区域范围的影响均未超过Ⅵ度。同时对场地地震效应进行了初步分析。运用野外地震地质调查、浅层人工地震法探测、钻孔联合剖面及电磁波CT探测和电子自旋共振(ESR)测年技术对目标断层活动性进行探测。本文系统完整的结合最新资料对研究区地震构造背景及目标断层进行综合分析、开展断层活动性鉴定后认为：横岗-罗湖断裂是由一系列走向南西-北东的断层组成,总体表现为逆断层,部分地段为正断层,断裂在中更新世早中期活动,研究区域内自1970年以来有5个小地震处于五华-深圳断裂与温塘-观澜断裂交汇地带；莲塘断裂是一条走向南西-北东、倾向北西的正断层,北支福田断裂在中更新世中期活动,南支田螺坑断裂在中更新世以前活动,断裂附近自1970年以来无地震活动；温塘-观澜断裂是一条走向南东-北西,倾向南西的正断层,断裂在中更新世中期之前活动,断裂自1970年以来无明显的地震活动。同时,对各种探测方法效果对比显示：在充分收集和分析相关资料,经过地震地质调查大致确定断层位置的基础上,以浅层地震勘探为主要手段,钻探和电磁波cT法进行必要的验证,是在弱构造活动区进行城市断层活动性研究和地震危险性分析的有效方法。结合深圳市目标断层的特征和地震危险性评价方法的适用条件,采用经验关系及区域构造类比方法,对目标断层进行了地震最大震级评估,得出横岗-罗湖断裂最大发震震级综合评估结果为Ms 6.5级；莲塘断裂最大发震震级综合评估结果为Ms 6.5级；温塘-观澜断裂最大发震震级综合评估结果为Ms 6.0级。更多还原

【Abstract】 The NE-SW and NW-SE trending faults are the major faults in Shenzhen. It has an important significance for the engineering geology environment evaluation and earthquake disaster mitigation to identify their activity, determine whether they are seismic active faults triggering destructive earthquake directly beneath cities and estimate their biggest magnitude and seismic hazard.The comprehensive analysis of regional seismic structural environments including the regional tectonic setting, the regional geophysics field characteristic, the modern diastrophism characteristic, the modern tectonic stress field characteristic, the regional geodynamic background and seismic activity indicates that the study area locates in the depression belt in north and northeast-middle of GuangDong, the big hillock intrusive rock masses and some small rock masses which belong to Late Pleistocene and Holocene formation cover the most of entire area and the main faults trend to NNW-NW. The study area is in the uplifting condition which inherits the block movement characteristic globally since the new tectonic movement, the deep structural environment has little difference, the violent earthquakes mainly distribute in the sea area where the historical earthquake that has an influence less than VI degree. At the same time, field seismic effect has been analyzed primarily.A comprehensive method including field earthquake geological investigation, the shallow layer artificial seismic method, the drill-hole union section-plane and the electromagnetic wave CT survey and the electron spin resonates (ESR) is used to detect the target fault activity. After the comprehensive analysis of regional seismic structural environments and the target fault activity systematically and wholly combined with the recent data and the detection to the fault activity, then, conclusion is that the HengGang-LuoHu fault is consist of a series of faults trending SW-NE which appear reversed fault globally and normal fault partially, and move in early-middle period of Middle Pleistocene, and that there are five small earthquakes in the connection region between WuHua-ShenZhen fault and WenTang-GuanLan fault since 1970, and that LianTang fault whose north branch FuTian fault exercises in the middle of Middle Pleistocene and south branch TianLuokeng fault moves before Middle Pleistocene, trends SW-NE, slips northwest and doesn’t move since 1970, moreover. and that WenTang-GuangLan fault which trends SE-NW and slips southwest campaigns before metaphase of Middle Pleistocene and doesn’t shake since 1970. Simultaneously, according to the effect which is made by comparing with various detection methods, it has indicated that using shallow seismic exploration mainly, correcting and verifying necessarily by drilling and electromagnetic wave CT method, is a good way to urban fault activity and seismic hazard analysis in weak tectonic area.Combining with the characteristics of ShenZhen target faults and applicable conditions of seismic hazard evaluation methods, a experience relationship and regional tectonic analogy method are used to assess the largest magnitude of the target faults, the comprehensive assessment results of HengGang-LuoHu fault, LianTang fault and WenTang-GuanLan fault are Ms 6.5 grade, Ms 6.5 grade and Ms 6.0 grade.更多还原