发扬李四光地震预报的科学思想     

李方全 《地质力学学报》2011,17(1):74-78

李四光教授关于地震地质工作中地震预报方面的重要观点和思想主要包括:地应力变化与地震密切相关;地震活动带中也存在相对安全的地区(“安全岛”理论);地震地质调查是地震预报的基础;地震是可以预测的,地应力的变化过程是地震预报的关键.他的“安全岛”理论及地震预报思想至今仍有着十分重要的理论意义和现实意义.  相似文献   

单桩复合地基静载荷试验系统的设计与应用研究     

巩天真  常积玉  韩鹏举 《岩土工程技术》2011,25(1):1-4

复合地基是通过褥垫层的调整作用,充分发挥桩间土的承载作用,使桩土共同承担荷载的地基。基于复合地基的实际工况,设计了一种单桩复合地基静载荷试验系统,既体现了褥垫层的调整作用,又可测得复合地基中桩体、桩问土、复合地基的荷载与其相应的沉降,同时可得出复合地基受力过程中桩土荷载分配过程与桩土应力比,提示了复合地基工作机理。通过工程实例测试,探讨了复合地基的工作机制,为复合地基的科研、设计与检测提供了依据。  相似文献   

海南石碌铁矿床构造变形特征及其与铁多金属成矿富集的关系   总被引：1，自引：0，他引：1  

许德如  吴俊  肖勇  陈福雄  王力  刘朝露  王智琳 《地质通报》2011,30(4):553-564

海南石碌铁矿曾被誉为“亚洲最大的富铁矿”,其形成、定位与褶皱变形及伴随的剪切、塑性流动等构造密切相关。石碌矿区构造变形大致分为早期(D1)复式向斜的形成时期、晚期(D2)褶皱叠加和剪切变形时期。后者又进一步分为韧-脆性变形(D2a),脆-韧性变形、层间滑脱断层形成(D2b)和脆性变形、矿体破坏(D2c)3个阶段。石碌铁矿床受NW—SE向复式向斜及其与NE—NNE向褶皱叠加所形成的横跨或斜跨褶皱的严格控制;褶皱过程所伴随的剪切变形和高温塑性流动是富铁矿形成的重要机制。复式向斜轴部,尤其是2期向斜褶皱轴的叠加部位往往可发现厚大的富铁矿体。  相似文献   

江西临川地区相山铀矿田构造应力场分析   总被引：7，自引：0，他引：7  

陈正乐  杨农  王平安  宫红良  韩凤彬  周永贵  邵飞  唐湘生  徐金山  喻建发 《地质通报》2011,30(4):514-531

相山铀矿田是中国最大的、与火成岩有关的中低温热液型矿床,断裂构造控矿特征明显。目前该矿床的后备资源出现危机,因此开展矿田构造研究,为深部及其外围找矿提供科学指导迫在眉睫。在野外观测分析和节理、擦痕实地测量的基础上,利用构造解析法、共轭剪节理分析法、断层擦痕反演模拟法及X光岩组法等,通过吴氏网投图分析和计算机的反演计算,确定了相山铀矿田多期次构造活动的变形特征及其主应力方向;并根据构造变形叠加关系及其成岩时代的确定,推断了应力作用的期次和时代。为此,将相山铀矿田的构造应力场划分为3期6个阶段,包括：成矿前的基底变形和早期火山活动阶段,早期矿化蚀变和第一、第二主成矿阶段,及其成矿期后阶段,矿体局部被错断;并深入分析了不同阶段构造活动及其铀成矿特征,探讨了区域构造应力场的演变与铀成矿作用关系,认为两者具有一致性特征,进而指出了区域富大矿体产出的有利构造部位。  相似文献   

胶东大磨曲家金矿床岩石磁组构、构造变形与金矿化     

江少卿  郝梓国  高帮飞  周应华 《地质通报》2011,30(9):1418-1428

在胶东地区招远-平度断裂带上的大磨曲家金矿区选取了典型的构造区域进行岩石磁组构研究。沿着断裂带在不同构造部位的36个采样点钻取了112个定向岩心样品,所有样品均沿勘探线布置。磁组构研究显示,研究区以弱磁性岩石为主,总体上,胶东群变质岩的磁化率值较高,而玲珑黑云母花岗岩的磁化率值较低,尤以碎裂程度高的强蚀变岩的磁化率值最低;磁化率各向异性方位主要为NE向挤压,磁组构所指示的构造应力场与大磨曲家矿区的区域挤压应力方向是相同的;对具不同程度矿化的81线的Au含量与80线磁组构各向异性度(P值)进行对比研究发现,P值与金品位呈负相关关系;弱矿化糜棱岩中的金矿化在磁面理发育的岩石中较为发育,成矿晚期,Au元素含量随着岩石磁性的减弱而增加,特别是在强应变后弛豫阶段矿液充填于相对张性的石英脉中Au含量最高。  相似文献   

渭北煤田合阳县北中深部控煤构造样式分析     

王辉 《中国煤炭地质》2011,(10):8-13,28

依据野外地表地质观测及地震、钻探最新的深部地质资料,结合对区域控煤构造认识,运用构造解析、构造应力场及地质力学分析等研究思路与方法,讨论了研究区控煤构造特征、构造样式以及成因。研究结果表明：研究区共有三类六种控煤构造样式,即挤压构造样式（宽缓褶皱、叠加褶皱）、走滑构造样式（反＂S＂型褶皱、＂入＂字型构造）及伸展构造样式（掀斜断块、堑垒构造）,其中以伸展构造样式发育为主要特征;研究区由东南向西北,构造变形强度由强变弱,先后经历了印支期南北向挤压、燕山中期北西向挤压和喜马拉雅期北东向挤压-走滑与北西-南东向伸展断陷作用;晚期形成的正断层不仅破坏了煤层的连续性,而且成为奥灰水储集和运移的主要通道,增大了底板突水的可能性,使煤炭资源开发受到影响。  相似文献   

冬季寒潮期间黄、渤海水位低频波动研究          下载免费PDF全文

李晓红  董礼先 《海洋与湖沼》2011,42(4):467-473

利用 POM(Princeton Ocean Model)海洋数值模式建立渤、黄、东海冬季三维环流动力学区域模型。模型在海-气边界使用包括风应力、气压和热通量的大气驱动, 海洋边界使用西太平洋模式提供的环流和潮位驱动, 综合模拟潮波运动、温度、盐度、环流变化和水位低频波动。 模拟了 2001 年 1 月寒潮过境时黄、 渤海水位低频波动及流场变化, 分析了其对大风过程、 气压、降温的响应, 发现冬季强劲的北风和西北风都可以通过抽吸振荡在渤、 黄海诱发水位的低频波动, 东北风则由于地形影响不能诱发渤、黄海的低频波动。气压和降温只是在波动幅度上有一定的影响。波动发源于渤海和北黄海, 最大波幅可以达到 0.6 m。波动进入南黄海后有沿黄海深槽西侧传播的倾向, 波动幅度在传播过程中逐渐减小。  相似文献   

The effect of wave-induced radiation stress on storm surge during Typhoon Saomai (2006)   总被引：5，自引：1，他引：4  

FENG Xingru  YIN Baoshu  YANG Dezhou  WILLIAM Perrie 《海洋学报(英文版)》2011,30(3):20-26

The effects of wave-induced radiation stress on storm surge were simulated during Typhoon Saomai using a wave-current coupled model based on ROMS (Regional Ocean Modeling System) ocean model and SWAN (Simulating Waves Nearshore) wave model.The results show that radiation stress can cause both set-up and set-down in the storm surge.Wave-induced set-up near the coast can be explained by decreasing significant wave heights as the waves propagate shoreward in an approximately uniform direction;wave-induced set-down far from the coast can be explained by the waves propagating in an approximately uniform direction with increasing significant wave heights.The shoreward radiation stress is the essential reason for the wave-induced set-up along the coast.The occurrence of set-down can be also explained by the divergence of the radiation stress.The maximum wave-induced set-up occurs on the right side of the Typhoon path,whereas the maximum wave induced set-down occurs on the left side.  相似文献   

Application of a BEM time stepping algorithm in understanding complex unsteady propulsion hydrodynamic phenomena     

Gerasimos K. Politis 《Ocean Engineering》2011,38(4):699-711

We solve the problem of unsteady potential flow around a system of arbitrarily moving rigid or flexible, lifting or non-lifting bodies, in an infinite fluid free of distributed vorticity. For the solution we use a time stepping algorithm and a potential based formulation of the corresponding free BVP. Nonlinear free shear layer dynamics are included in our modeling. This is a major innovation in treating complex unsteady propulsion problems since no simplifying assumptions (like that of a helicoidal wake) are used regarding the wake model. Bilinear quadrilateral elements are used to describe body and shear layer geometry at each time t. Three types of Kutta conditions can be alternatively applied for the determination of the shed vorticity from lifting bodies. The theoretical and numerical aspects of the method are presented followed by a number of applications, elucidating the qualitative and quantitative physical characteristics of a number of complex unsteady propulsion problems.  相似文献   

Postbuckling of shear deformable stiffened anisotropic laminated cylindrical shell under axial compression     

Zhi-Min Li  De-Qing Yang 《Ocean Engineering》2011,38(10):1246-1255

A postbuckling analysis is presented for a shear deformable anisotropic laminated cylindrical shell with stiffener of finite length subjected to axial compression. The material of each layer of the shell is assumed to be linearly elastic, anisotropic and fiber-reinforced. The governing equations are based on a higher order shear deformation shell theory with von Kármán-Donnell-type of kinematic nonlinearity and including the extension/twist, extension/flexural and flexural/twist couplings. The ‘smeared stiffener’ approach is adopted for the beam stiffeners. This arrangement allows the beam stiffeners to be assembled directly into the global stiffness matrix. The nonlinear prebuckling deformations and initial geometric imperfections of the shell are both taken into account. A singular perturbation technique is employed to determine the buckling loads and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling response of perfect and imperfect, grid, axial, ring stiffened, and unstiffened shells. The results confirm that there exists a compressive stress along with an associate shear stress and twisting when the anisotropic shell is subjected to axial compression. The postbuckling equilibrium path is unstable for the moderately thick cylindrical shell under axial compression and the stiffened shell structure is imperfection-sensitive.  相似文献