Theoretical research on geoelectric anomaly caused by streaming potential during earthquake preparation     

朱涛  赵和云 《地震学报(英文版)》2001,14(4):425-433

IntroductionAfter scientists at home and abroad have studied for many years, most of them take streaming potential (SP) as the most possible mechanism for the generation of self-potential anomaly during earthquake preparation. SP refers to electric signal, which generates local or regional electric field, produced when a fluid flows in a porous medium, as a sequence of the change of crustal stress or strain. Many facts suggest that SP is the most possible mechanism of generating self-potenti…  相似文献   

三维介质界面裂纹的动力分析     

陶伟明  曹志远 《地震工程与工程振动》1995,15(1):111-118

本文通过区域的连续映射推导了一种映射半解析边界元法，将其应用于界面裂纹问题的动力分析，可大大减小计算一。典型算例的结构表明，本文方法是非常有效的，并可推广应用于三维复杂形状裂纹的计算问题。  相似文献   

Crack－induced　anisotropy　in　the　crust　from　shear　wave　splitting　observed　in　Tangshan　region，North　China   总被引：11，自引：0，他引：11  

高原  郑斯华  孙勇 《地震学报(英文版)》1995,8(3):351-363

Ｃｒａｃｋ－ｉｎｄｕｃｅｄａｎｉｓｏｔｒｏｐｙｉｎｔｈｅｃｒｕｓｔｆｒｏｍｓｈｅａｒｗａｖｅｓｐｌｉｔｔｉｎｇｏｂｓｅｒｖｅｄｉｎＴａｎｇｓｈａｎｒｅｇｉｏｎ，ＮｏｒｔｈＣｈｉｎａＹｕａｎＧＡＯ（高原）Ｓｉ－ＨｕａＺＨＥＮＧ；（郑斯华）ａｎｄＹｏｎｇ...  相似文献   

滇西北地区断层破碎带宽度与断层错距的统计关系   总被引：1，自引：0，他引：1  

皇甫岗  王晋南 《地震研究》1993,(4)

本文以非粘土断层泥带宽度与断层错距在断层(带)发育中期线性相关的实验结果为依据,对滇西北地区断层破碎带宽度(W)与断层错距(D)的关系作了统计分析,目的在于建立一种从断层破碎带几何特征反演断层背景位移的新方法。通过对该区中等发育程度的33条断层48组样本的统计,得到相关性较好的D=18.5W的经验关系式,同时还就这一关系式的适用范围及影响因素进行了分析讨论。应用D—W关系,确定了直线型的剑川断裂中北段的背景位移分布,并提出断层的背景位移分布可作为断层分段的一个重要指标。  相似文献   

Finite Element Study On the Closure of Thermal Microcracks In Feldspar/Quartz-Rocks—Ii. Intra-, Transgranular and Mixed Cracks     

Arno Zang 《Geophysical Journal International》1993,113(1):32-44

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The role of the chemical environment in frictional deformation: Stress corrosion cracking and comminution   总被引：23，自引：0，他引：23  

J. Dunning  B. Douglas  M. Miller  S. McDonald 《Pure and Applied Geophysics》1994,143(1-3):151-178

The roles of chemically assisted crack and fracture propagation and chemically assisted comminution in frictional deformation are evaluated in this study. Double cantilever beam (DCB) crack propagation data are presented which show that the role of pH in chemically assisted fracture, and to a lesser extent the role of ionic concentration are important in stress corrosion cracking. Data on very slow crack growth and the stress corrosion limit are also presented. These data suggest that stress corrosion cracking may play an important role in compound earthquakes and in asperity breakdown in faults. The comminution literature is also reviewed in order to assess the role of chemically assisted comminution in frictional deformation. It appears that chemically assisted comminution may be important at low and high ionic strength because it may reduce the effective viscosity and the shear strength of fault gouge. At intermediate ionic concentration the role of pH, as an agent which enhances crack and fracture propagation, appears to be more important in reducing the coefficient of sliding friction.  相似文献   

Static　solution　of　a　crack　degenerated　from　dynamic　solution　of　a　propagating　crack     

李世愚  陈运泰 《地震学报(英文版)》1994,7(3):389-395

ＳｔａｔｉｃｓｏｌｕｔｉｏｎｏｆａｃｒａｃｋｄｅｇｅｎｅｒａｔｅｄｆｒｏｍｄｙｎａｍｉｃｓｏｌｕｔｉｏｎｏｆａｐｒｏｐａｇａｔｉｎｇｃｒａｃｋＳｈｉ－ＹｕＬＩ（李世愚）ａｎｄＹｕｎ－ＴａｉＣＨＥＮ（陈运泰）（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ...  相似文献   

地质特征轨迹的出露概率研究     

周小文 《岩土力学》2004,25(Z2):89-92

将地质特征的发展轨迹视为Brown运动.基于Brown运动理论,在裂隙穿越矩形区域概率公式的基础上,推导了单条裂隙轨迹和多条裂隙轨迹穿越任意区域的概率公式,并用算例进行了演算,从结果可知,如果通过一些实际工程的考察,确定出合理的轨迹运动参数,则用Brown运动有可能较好地模拟岩体裂隙(或其它地质特征轨迹)的运动规律.利用得到的概率公式,研究了矩形区域(边长为a,b)内裂隙的穿越概率与归一化距离b/a之间的关系.结果表明,如果地质特征轨迹符合Brown运动,则在0≤b/a≤1范围内,穿越概率随b/a的增加急剧降低;当b/a>1时,随着b/a的增加,概率减小比较缓慢.  相似文献   

不同加腋宽度下钢筋混凝土偏心节点的抗裂性能   总被引：1，自引：0，他引：1  

王静峰  孙捷 《世界地震工程》2004,20(4):67-70

通过五榀钢筋混凝土梁柱偏心节点试件在低周反复荷载下的试验研究，探讨了不同梁端水平加腋宽度对节点核芯区抗裂性能的影响，提出偏心节点抗裂度计算的建议公式。  相似文献   

Scattering of waves in elastic media containing passive and active cracks     

Masatoshi Miyazawa  Ichiro Nakanishi 《Geophysical Journal International》2006,165(2):658-667

Scattering of wavefields in a 3-D medium that includes passive and/or active structures, is numerically solved by using the boundary integral equation method (BIEM). The passive structures are velocity anomalies that generate scattered waves upon incidence, and the active structures contain endogenous fracture sources, which are dynamically triggered by the dynamic load due to the incident waves. Simple models are adopted to represent these structures: passive cracks act as scatterers and active cracks as fracture sources. We form cracks using circular boundaries, which consist of many boundary elements. Scattering of elastic waves by the boundaries of passive cracks is treated as an exterior problem in BIEM. In the case of active cracks, both the exterior and interior problems need to be solved, because elastic waves are generated by fracturing with stress drop, and the growing crack boundaries scatter the incident waves from the outside of the cracks. The passive cracks and/or active cracks are randomly distributed in an infinite homogeneous elastic medium. Calculations of the complete waveform considering a single scatter show that the active crack has weak influence on the attenuation of first arrivals but strong influence on the amplitudes of coda waves, as compared with those due to the passive crack. In the active structures, multiple scattering between cracks and the waves triggered by fracturing strongly affect the amplitudes of first arrivals and coda waves. Compared to the case of the passive structures, the attenuation of initial phase is weak and the coda amplitudes decrease slowly.  相似文献