珠江三角洲广从断裂东侧"西淋岗断层"成因论证     

王萍  郭良田  董好刚  盛强  欧阳立胜  尹行 《岩石学报》2011,27(10):3129-3140

广从断裂是粤中地区一条重要的北东向基底断裂,对于该断裂在珠江三角洲隐伏段的晚第四纪活动性的认识存在分歧.针对最近在广从断裂东侧佛山市西淋岗发现的断错晚第四纪地层现象,开展了地质地貌调查、探槽揭露、第四系年代测定和浅层人工地震探测等工作.对“西淋岗断层”的几何学特征及与基岩断裂的相关性进行了探测和分析,论证了其成因.“西淋岗断层”是新生的重力滑动面,并不是晚第四纪活动断层,与地震无关.目前尚未发现广从断裂晚第四纪以来活动的地质地貌证据,因此不能说明该断裂具备发生强烈地震的构造能力.  相似文献   

遗传算法反演龙门山断裂带断层三维滑动参数研究     

张秀霞  张永志 《西安地质学院学报》2011,(2):217-220

利用位错理论模型将遗传算法运用于断层三维滑动参数反演问题的求解,采用川西地区2004—2007年GPS观测数据对龙门山断裂带主要断层的三维滑动速率进行计算分析。结果表明：反演结果在量值上整体较小,与地质结果具有较好的一致性,走滑分量︱U1︱〈3.2 mm/a,倾滑分量︱U2︱〈1.54 mm/a,张开分量︱U3︱〈2.5mm/a,低滑动速率反映断层的闭锁及应力的积累及大地震发生的危险性;局部分量较地质结果偏大,反映实测GPS数据反演结果体现的是断层实时活动状态;遗传算法的全局收敛、不依赖初值等优点使结果更加稳定,而张开分量显示局部不规律性,表现出各子断层空间活动不均匀性。  相似文献   

CINRAD／SB型新一代天气雷达频综故障诊断方法          下载免费PDF全文

王全周  崔炳俭  杨奇 《气象与环境科学》2011,34(4):88-91

通过对CINRAD／SB型新一代天气雷达频综故障现象、报警信息分析,根据频综输出信号流程,结合关键点参数测试,总结出快速定位频综故障的方法,并介绍了应用这种方法快速诊断定位故障的个例。  相似文献   

利用地震叠前数据预测火山岩裂缝的方法和效果分析——以松辽盆地北部徐家围子断陷营城组火山岩为例   总被引：1，自引：0，他引：1       下载免费PDF全文

姜传金  鞠林波  张广颖  初丽兰 《地球物理学报》2011,54(2):515-523

裂缝问题是火山岩复杂岩性油气藏勘探开发中必须考虑的重要因素之一.火山岩储层裂缝预测的准确性直接影响着油气的产能、钻井工艺和增产改造措施等.本文主要根据等效HTI介质(扩容各向异性介质)的特性,立足地下介质各向异性理论,利用三维地震叠前P波在HTI介质中的属性分布特征来检测裂缝的发育情况.利用三维地震叠前P波裂缝检测技术在松辽盆地北部徐家围子断陷深层营城组火山岩中尝试开展了储层裂缝发育预测研究.通过研究建立了火山岩裂缝地震叠前预测方法,并对营城组火山岩裂缝发育情况进行预测,结果表明裂缝主要分布在工区中部构造高部位,发育方向以北北西向为主.最后利用测井资料和钻井产能资料等进行效果分析,证实该技术对于认识火山岩储层裂缝发育具有实际应用价值,说明应用地震资料开展储层裂缝预测具有横向分辨率高、实现井间分布描述和宏观空间分布规律清楚等特点.  相似文献   

青藏高原东缘重力导纳模型均衡异常时空特征   总被引：13，自引：7，他引：6       下载免费PDF全文

陈石  王谦身  祝意青  蒋长胜  王武星  卢红艳  刘端法  郭凤义 《地球物理学报》2011,54(1):22-34

青藏高原东缘地处南北地震带,在卫星自由空气重力异常图上对应明显的正负异常梯级带变化特征,沿着异常梯级带分布多条深大断裂,属于构造单元的边界区域.本文利用重力导纳分析方法,计算了该区重力导纳模型均衡异常背景场;通过与Airy模型和弹性板模型的均衡重力异常特征对比,结合地震活动性分布特点,评价均衡重力异常计算结果和选择计算...  相似文献   

Theory and experimental study for sliding isolators with variable curvature     

Lyan‐Ywan Lu  Shih‐Wei Yeh 《地震工程与结构动力学》2011,40(14):1609-1627

Because a conventional isolation system with constant isolation frequency is usually a long‐period dynamic system, its seismic response is likely to be amplified in earthquakes with strong long‐period wave components, such as near‐fault ground motions. Seismic isolators with variable mechanical properties may provide a promising solution to alleviate this problem. To this end, in this work sliding isolators with variable curvature (SIVC) were studied experimentally. An SIVC isolator is similar to a friction pendulum system (FPS) isolator, except that its sliding surface has variable curvature rather being spherical. As a result, the SIVC's isolation stiffness that is proportional to the curvature becomes a function of the isolator displacement. By appropriately designing the geometry of the sliding surface, the SIVC is able to possess favorable hysteretic behavior. In order to prove the applicability of the SIVC concept, several prototype SIVC isolators, whose sliding surfaces are defined by a sixth‐order polynomial function, were fabricated and tested in this study. A cyclic element test on the prototype SIVC isolators and a shaking table test on an SIVC isolated steel frame were all conducted. The results of both tests have verified that the prototype SIVC isolators do indeed have the hysteretic property of variable stiffness as prescribed by the derived formulas in this study. Moreover, it is also demonstrated that the proposed SIVC is able to effectively reduce the isolator drift in a near‐fault earthquake with strong long‐period components, as compared with that of an FPS system with the same friction coefficient. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

A simulation‐based framework for risk assessment and probabilistic sensitivity analysis of base‐isolated structures     

Alexandros A. Taflanidis  Gaofeng Jia 《地震工程与结构动力学》2011,40(14):1629-1651

A versatile, simulation‐based framework for risk assessment and probabilistic sensitivity analysis of base‐isolated structures is discussed in this work. A probabilistic foundation is used to address the various sources of uncertainties, either excitation or structural, and to characterize seismic risk. This risk is given, in this stochastic setting, by some statistics of the system response over the adopted probability models and stochastic simulation is implemented for its evaluation. An efficient, sampling‐based approach is also introduced for establishing a probabilistic sensitivity analysis to identify the importance of each of the uncertain model parameters in affecting the overall risk. This framework facilitates use of complex models for the structural system and the excitation. The adopted structural model explicitly addresses nonlinear characteristics of the isolators and of any supplemental dampers, and the effect of seismic pounding of the base to the surrounding retaining walls. An efficient stochastic ground motion model is also discussed for characterizing future near‐fault ground motions and relating them to the seismic hazard for the structural site. An illustrative example is presented that emphasizes the results from the novel probabilistic sensitivity analysis and their dependence on seismic pounding occurrences and on addition of supplemental dampers. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

2009年11月至2010年11月27次中强地震的快速矩张量解          下载免费PDF全文

刘超  许力生  陈运泰 《地震学报》2011,33(4):550-552

经过半个世纪的发展,地震震源的矩张量表示及其反演已日臻成熟(Dziewonski,Woodhouse,1983).矩张量解不但能够较好地反映地震震源的特性,还能为其它研究提供有用的参考.一些科研机构和组织,如美国地质调查局(USGS)和全球矩心矩张量研究组(GCMT)已经能够在震后5小时内准实时地发布矩  相似文献   

城市活动断层探测成果图件集的编制规范研究   总被引：2，自引：1，他引：1       下载免费PDF全文

吴熙彦  徐锡伟  安艳芬  王银 《地震地质》2011,(4):978-989

城市活动断层探测成果图件集是近年国家活动断层探测科学工程项目开展以来形成的重要资料,其集成编绘将有助于今后地震地质研究和防震减灾的开展。城市活动断层探测成果图件集包括20个城市的1:250000区域地震构造图与1:50000活动断层分布图。文中系统详细地探讨了区域地震构造图与活动断层分布图地图信息的组织与表达、设计思想、制图综合、图例规范与编制过程。最后,还简要介绍了基于ArcGIS平台的计算机规范化制图过程。  相似文献   

汶川Ms8.0地震灾害的非对称分布与成因分析          下载免费PDF全文

周庆  张春山  陈献程 《地震学报》2011,33(4):492-504

在汶川Ms8.0地震中,地震灾害在灾区相对于发震断层,呈现各种非对称分布.断层高角度逆冲诱发的崩塌、滑坡的规模与数量在断层上盘区远远高于断层下盘区,在垂直断层方向,高烈度区断层上盘宽度往往大于下盘宽度,上述不对称性反映了逆断层型地震存在加速度峰值的上盘效应;而在破裂的传播方向存在的地震波多普勒效应则造成沿长轴方向东北部...  相似文献