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黑山峡大柳树坝址区断裂构造格局与工程抗断问题研究 总被引：4，自引：0，他引：4
青藏高原是全球陆内地震活动最为集中而强烈的分布区带之一，位于高原块体东北缘的祁连山逆冲推覆型活动山链又是其中最强烈的现代活动构造带之一。大柳树坝址区即位于该活动山链的北祁连山前主边界逆冲断裂活动带向东延伸的分支断裂，即古浪-中卫-同心弧形逆冲走滑活动断裂带内的东段，中卫-同心弧形逆冲走滑活动断裂带的香山-天景山逆冲推覆构造带内。逆冲带内的主干活动断裂F201的规模及活动强度是影响坝址稳定的主要因素。本文通过分析大柳树坝址区基本断裂构造格局，阐述了F201断层活动对坝区内另一条主干断层F7（8）以及位于坝址上分支断层F39、F40的控制牵动效应。通过室内有限元数值模拟，定量分析了断层F201的活动对分支断层F39、F40的牵动程度。 相似文献
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坐落于中卫—同心逆冲断裂带中间部位的黄河黑山峡大柳树坝址距F201发震断层垂直距离不足1.5km。在坝址区内,中卫—同心断裂带由数条断层组成,并可进一步分为主干断层、分支断层。这些断层与主干断层F201具有密切关系。统计表明,在青藏高原及其周缘地区,当发生7级以上破坏性地震时,距发震断裂两侧3~5km的范围内都有可能出现断层的分支破裂、次生破裂等错断效应。晚更新世以来沿F201发生过多次地震破裂事件,大柳树坝址处于7级以上地震时的分支破裂发生带内,因此存在工程错断可能。三维有限元数值模拟结果表明,F201发生错动时,坝址地段分支断层F93、F39、F40相对于F201的错动比率处分别达到14.38%、12.00%和9.84%以上。 相似文献
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贵定县四寨水库挡水建筑物由拱坝、重力墩、重力墙及混凝土面板堆石坝几种建筑物组成,其中副坝为混凝土面板堆石坝。副坝基础发育有F9断层,影响带有35 m,断层充填物为紫红色、灰色页岩,干燥状态下物理力学指标较高,但遇水易软化成泥,软化后物理力学指标迅速下降。本文分析了F9断层带对副坝趾板及对实体的影响以及处理措施。 相似文献
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从F3断层的构造特征入手,分析了矿区内赋存的各种矿产与该断层的关系,对矿区寻找矿产具有一定的指导意义. 相似文献
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坐落于中卫-同心活动断裂带中间部位的黄河黑山峡大柳树坝址,距F201发震断层垂直距离不足1.5km。统计表明,在青藏高原及其周缘地区,当发生Ⅶ级以上破坏性地震时,距发震断裂两侧3～5km的范围内都有可能出现断层的分支破裂、次生破裂等错断效应。大柳树坝址处于Ⅶ级以上地震时的分支破裂发生带内,因此,存在工程错断效应问题。三维有限元数值模拟结果表明,断层F201发生错动时,坝址地段断层F93、F39、F40相对于F201的错动比率处分别达到14.38%、12.00%和9.84%以上。 相似文献
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由于房屋建设开挖,浙江省江山市五家垄出露6条新鲜小断层,属于江绍断裂的次级组成部分.结合野外地质勘查,运用粉晶X射线衍射和穆斯堡尔谱技术对五家垄断层的3条小断层(F1、F2与F3)的断层泥和断层围岩进行矿物组成和铁元素化学种分布特征的对比分析与研究发现:断层围岩与断层泥的矿物成分主要为石英和黏土矿物,还含有少量钠长石和方解石,其中黏土矿物以伊利石、伊蒙混层和高蒙混层为主,还含有少量的绿泥石、高岭石和极少量的蒙脱石和蛭石;除采自F2断层的JS07样品外,断层围岩中造岩矿物含量高于断层泥,而断层泥黏土含量高于断层围岩;F1断层泥黏土矿物只有伊利石,显示断层带内为一个相对稳定的环境,F2与F3断层泥中伊利石含量低于断层围岩,蒙脱石、伊蒙混层含量高于断层围岩,指示其处于一个潮湿、强氧化环境;F1断层围岩高含量的还原性铁指示断层围岩形成的过程中有还原性物质的参与或者处于相对封闭的环境,F1、F3断层泥与F3上盘高含量的氧化铁亦说明F1、F3断层近期不活跃或者是块体内断层;断层带内黏土矿物的类型及组合与断层带内的氧化还原环境显示五家垄断层处于相对稳定的环境,但断层带内伊利石含量较高,有利于断层活动,五家垄断层的活动性与发震可能性应引起重视. 相似文献
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贵州松桃西溪堡大型锰矿床F1犁式断层特征及对锰矿体破坏与保存作用探讨 总被引：2，自引：2，他引：0
本文以西溪堡锰矿床F1犁式正断层(冷水溪断层)为例,从分析研究F1断层所切穿的地层岩性、结构和矿物成分特征入手,探讨F1犁式正断层的特征、形成条件与成因.认为该犁式断层的形成,是由于具有超压的含锰岩系碳质页岩中的蒙脱石转变为伊利石过程中,产生的高孔隙流体压力,导致在断层通过上部脆性及其相对脆性沉积岩层进入大塘坡组第一段黑色含锰岩系(Nh1d1)这一韧性层时,迅速降低断层上覆岩层的负荷强度,使断层面倾角变缓,以致沿层面滑脱,是形成F1犁式正断层的主要原因.通过对F1断层的探讨分析研究,认为黔东及毗邻地区的“大塘坡式”锰矿区,普遍发育犁式正断层是存在的,其对锰矿体的破坏和后期保存有重要的影响.因此,开展犁式断层的特征研究,对指导黔东及毗邻地区“大塘坡式”锰矿普查找矿、开展攻深找盲,意义重大. 相似文献
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新疆克孜尔水库F2活断层活动特征分析 * 总被引：1，自引：0，他引：1
摘 要 新疆克孜尔水库区内F2活断层的活动规律对水库的安全性有重要影响,对F2断层短水准长序列的观测分析表明:F2断层下盘近40年来持续发生着由南向北的地倾运动。这既影响了短水准高差计算结果,也影响了位错模型水平扭动量和滑动角两个用于评价断层活动性的参数的计算结果,从而使F2断层活动性评价失去客观性。本文通过第1形变监测站人工短水准前尺读数长序列走势分析获得F2活断层下盘测线方向上12米处地倾活动的年变速率（1979-2006）为0.224mm/a,根据库区F2活断层两侧地表沉降速率等值线图确定、验证第1形变监测站上、下盘测线方向上地倾活动年变速率（1991-2002）分别是0.03mm/a、0.07mm/a。对水平扭动量和滑动角的计算和分析表明:F2活断层近10余年来的活动虽与水库蓄水、库水沿活断层下渗、河流改道及地壳运动关系密切,但尚无法认定其活动正在或已经加剧。 相似文献
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现行的勘察设计行业《岩土工程勘察规范》(GB50021-2001/2009年版)、《建筑抗震设计规范》(GB50011-2010)、《工程场地地震安全性评价》(GB17741-2005),对于活动断裂的定义有一定差异,使得不同的勘察设计单位对同一条断裂的评价结果不一致,甚至相互矛盾。本文以昆明市为例,通过分析不同规范对于活动断裂的定义,指出其中的问题与差异,结合典型断层地质剖面与震害实例,简要阐述地质上判定活动断裂的主要依据,即不应以《岩土工程勘察规范》(GB50021-2001/2009年版)规定的全新地质时期(一万年)内有无地震活动来判定断裂是否为全新活动断裂,应以《工程场地地震安全性评价》(GB17741-2005)规定的断裂是否错动地表或近地表相应时代的地层,来判定其活动时代。 相似文献
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The detailed characteristics of the Paleozoic strike-slip fault zones developed in the northern slope of Tazhong uplift are closely related to hydrocarbon explorations. In this study, five major strike-slip fault zones that cut through the Cambrian-Middle Devonian units are identified, by using 3D seismic data. Each of the strike-slip fault zones is characterized by two styles of deformation, namely deeper strike-slip faults and shallower en-echelon faults. By counting the reverse separation of the horizon along the deeper faults, activity intensity on the deeper strike-slip faults in the south is stronger than that on the northern ones. The angle between the strike of the shallower en-echelon normal faults and the principal displacement zone(PDZ) below them is likely to have a tendency to decrease slightly from the south to the north, which may indicate that activity intensity on the shallower southern en-echelon faults is stronger than that on the northern ones. Comparing the reverse separation along the deeper faults and the fault throw of the shallower faults, activity intensity of the Fault zone S1 is similar across different layers, while the activity intensity of the southern faults is larger than that of the northern ones. It is obvious that both the activity intensity of the same layer in different fault zones and different layers in the same fault zone have a macro characteristic in that the southern faults show stronger activity intensity than the northern ones. The Late Ordovician décollement layer developed in the Tazhong area and the peripheral tectonic events of the Tarim Basin have been considered two main factors in the differential deformation characteristics of the strike-slip fault zones in the northern slope of Tazhong uplift. They controlled the differences in the multi-level and multi-stage deformations of the strike-slip faults, respectively. In particular, peripheral tectonic events of the Tarim Basin were the dynamic source of the formatting and evolution of the strike-slip fault zones, and good candidates to accommodate the differential activity intensity of these faults. 相似文献
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V. S. Rozhdestvenskii 《Russian Journal of Pacific Geology》2008,2(1):15-24
Large-scale geological maps available for individual areas in the Central Sakhalin Fault zone and geological-geophysical maps of Sakhalin and surrounding sea areas were analyzed to elucidate the tectonic evolution of the fault zone determined by movements of crustal blocks due to the opening of rift basins. Changes in the direction of horizontal compression in the Sakhalin fold system from diagonal (NW-SE) to near-latitudinal resulted in the transformation of near-meridional right-lateral strike-slip faults into reversed faults in the Late Miocene. This allows Sakhalin faults to be interpreted as a zone of recent right-lateral shear between Eurasian and Sea of Okhotsk plates. 相似文献
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The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830.The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation. 相似文献
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The Halten Terrace, offshore mid-Norway, is underlain by a Triassic evaporitic package that is rheologically weak, and led to decoupling of fault systems during Middle Jurassic to Early Cretaceous rifting. We use 2D and 3D reflection seismic data, constrained by wells, from the southern Bremstein Fault Complex of the Halten Terrace to map faults and key stratigraphic horizons, and analyse throw variations along faults, allowing us to constrain patterns of fault segmentation and linkage within the complex. The Bremstein Fault Complex has an overall tilted monoclinal geometry with localised fault systems at base salt level associated with overlying, highly distributed systems of normal faults. Vertical strain partitioning across the evaporite package means that sub-evaporite and supra-evaporite fault populations acted as semi-independent fault systems. Supra-evaporite faults are partly gravity-driven, and controlled by sub-evaporite faulting and consequent tilting of the evaporitic package. This behaviour leads to a wide variety of possible vertical linkage patterns of faults across the evaporite package. A greater variety of lateral segment linkage patterns occurs in evaporite-detached normal fault systems than in normal fault systems developed in the absence of evaporite units. Segment boundary styles can also be modified by migration of evaporite. Some segment boundaries are associated with a footwall anticline and hanging-wall syncline, in contrast to the footwall synclines and hanging-wall anticlines widely described in studies of normal fault systems. 相似文献
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晚中生代是华北地块构造演化的转折时期。由出露于沂沭断裂带、鲁西地体、鲁东地体的中生代地层、岩浆,结合断裂活动年代学、区域地质等资料分析,可以将沂沭断裂带晚中生代构造演化划分出距今约160Ma、130～110Ma、90～80Ma等3个关键时期,并分别与左行压剪、左行张剪、右行压剪构造活动相对应。晚中生代沂沭断裂带与鲁西北西向断裂系间的几何学、运动学、年代学的共轭匹配关系表明,它们为特定构造动力学背景下形成的一组共轭断裂系。同时对鲁东地体晚中生代构造演化、鲁东北西向断裂系特征,以及沂沭断裂带、北西向断裂系晚中生代构造演化的动力学背景进行探讨。 相似文献
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本文以山西省汾西矿区崔家淘井田断层构造的展布规律、断层面构造岩特征民层滑动擦痕为依据，分析断层发育的力学机制衣成生欠，应用赤平投影图矿区两条主干断层，得出 区三向主支应力轴方向的认识，提出一种在华北地区有代表性煤矿区展布模式芝对断层的识别和预测具有指导意义。 相似文献
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The aim of this study is to demonstrate how the 12 October 1992 Cairo earthquake relates to the spatial geometry of the northern Egyptian fault systems. A box-counting algorithm was used, in a focused down approach (from regional to local scales) to analyze the fractal dimensions of the existing faults. The results indicate that these faults display fractal geometries that are self-similar over two to three orders of magnitude. It is shown that the northwest-southeast (Northern Red Sea) trending fault system has the lowest fractal dimension value. Coincidentally, this fault trend is the one that the fault plane solution shows to be active. 相似文献
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霍州矿区煤层中小断层发育规律及其数值模拟 总被引：1，自引：0，他引：1
小断层的发育是影响矿井生产的重要因素,本文探索霍州矿区煤层中小断层发育规律及影响小断层发育的因素,并从数值模拟计算角度来深化小断层发育规律的认识。 相似文献