Electrical resistivity changes in rocks during frictional sliding and fracture   总被引：3，自引：0，他引：3  

Chi-yuen Wang  P. N. Sundaram  Richard E. Goodman 《Pure and Applied Geophysics》1978,116(4-5):717-731

Significant changes of electrical resistivity of saturated rocks and water pressure along sliding surface occurred during stick-slips in our direct shear experiment. Two types of changes of electrical resistivity occurred. In the first, resistivity decreased with increasing shear stress, reached minimum together with a sudden release of shear stress and returned to a higher value immediately afterwards. In the second, resistivity again decreased with increasing stress but, in contrast to the first type of changes, it decreased further upon the sudden drop of shear stress. The magnitude and the direction of the changes of water pressure on the sliding surface during stick-slip were not uniform, indicating local variations of surface deformation.  相似文献   

Rock friction-effect of confining pressure,temperature, and pore pressure     

R. M. Stesky 《Pure and Applied Geophysics》1978,116(4-5):690-704

This paper reviews many of the mechanical properties of faulted and jointed rock under pressure and temperature and in the presence of water. At low effective confining pressures (below about 1 kilobar), the friction strength is quite variable and depends on the frictional resistance between gouge particles or asperities and on the dilatancy of the fault. At higher pressures the friction strength is nearly independent of mineralogy, temperature, and rate, at least for rocks whose friction strength is less than the failure strength. Water tends to slightly weaken the fault. The type of sliding motion, whether stick-slip or stable sliding, is much more affected by environmental and mineralogical factors. In general, stick-slip is dominant at high pressures and low temperatures, in the presence of strong minerals such as quartz and feldspar, in the absence of gouge, for lower surface roughness, and perhaps in the presence of water. The microscopic deformation mechanisms are poorly understood. At low temperatures, cataclasis dominates in rocks containing mostly quartz or feldspar, and plastic deformation in rocks containing mostly calcite or platy silicates. At high temperature most minerals deform plastically, producing a greater temperature-and rate-dependence of the friction strength. Glass has been found in some sliding surfaces in sandstone.  相似文献   

用有限元方法研究含摩擦多断层周围的应力场   总被引：1，自引：1，他引：1       下载免费PDF全文

滕春凯  白武明 《地球物理学报》1992,35(4):469-478

本文使用有限元方法,研究了含摩擦多断层问题.在研究中,计算了几个物理模型（如共线、共轭等）和含摩擦多断层的应力场,并用计算机绘制出一批含摩擦多断层应力等值线图.结果表明,含摩擦多断层的应力场与单一断层相差甚远,在断层的交汇处,应力集中的范围和程度远大于断层的外端;断层的应力场在空间上分布很不均匀;高应力区和低应力区的分布随载荷作用方式和断层的形态各异.断层内的摩擦力对应力场的分布有很大的影响,并可能对断层的扩展行为起着非常重要的影响.  相似文献   

Methods to project plasticity models onto the contact surface applied to soil structure interactions     

《Computers and Geotechnics》2015

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A two-parameter expression for failure surfaces     

Dong Su  Zhi-Liang Wang  Feng Xing 《Computers and Geotechnics》2009

The Mohr–Coulomb, Tresca and Von Mises criteria are classical failure criteria, widely accepted and used for various materials. To take into account the influence of intermediate principal stress on the strength of soil, Bishop, Lade–Duncan and Matsuoka proposed criteria in terms of three principal stresses or three stress invariants. This note describes an expression with two parameters for modeling the shape of the failure surface in the octahedral plane. By studying the roles of these two parameters and comparing the new criterion with the aforementioned criteria, the advantage and flexibility of the proposed function is explored. Application of the function is demonstrated by fitting the new surface to experimental data for various soils.  相似文献   

村镇建筑砌体结构滑移隔震性能研究1     

史庆轩  戎翀  王秋维  吴勇锋 《震灾防御技术》2014,9(4):891-897

村镇建筑多以砖混结构为主,抗震性能相对较弱,砂垫层摩擦滑移隔震技术由于诸多优点较适合广大农村建筑.本文介绍了砂垫层基础滑移隔震的设计原则和分析模型,以常见的两层砖混结构为例,采用Abaqus有限元软件分析不同摩擦系数、不同加速度峰值下隔震层的滑移,并在此基础上确定隔震层在多遇和罕遇地震作用下的摩擦系数及滑移量建议限值;通过验算不同砂浆的抗震受剪承载力,得出不同摩擦力作用下满足抗震受剪承载力的最低砂浆标准,所得结论对农村滑移隔震建筑的选材具有一定参考意义.  相似文献   

边界层参数化方案对边界层热力和动力结构特征影响的比较   总被引：8，自引：3，他引：5       下载免费PDF全文

黄文彦  沈新勇  王卫国  黄伟 《地球物理学报》2014,57(5):1399-1414

本文利用高分辨率中尺度WRF模式,通过改变边界层参数化方案进行多组试验,评估该模式对美国北部森林地区边界层结构的模拟能力,同时比较了五种不同边界层参数化方案模拟得出的边界层热力和动力结构.结果表明：除个别方案外,配合不同边界层方案的WRF模式都能成功模拟出白天对流边界层强湍流混合特征和夜间稳定边界层内强逆温、逆湿和低空急流等热力和动力结构.非局地YSU、ACM2方案在白天表现出强的湍流混合和卷夹,相比于局地MYJ、UW方案,模拟的对流边界层温度更高、湿度更低、混合层高度更高、感热通量更大,更接近实际观测,这表明在不稳定层结下考虑非局地大涡输送更为合理,但局地方案在风速和风向的预报上存在一定优势.TEMF方案得到的白天局地湍流混合强度为所有方案中最弱,混合层难以发展,无法体现对流边界层内气象要素垂直分布均匀的特点.对于夜间稳定边界层的模拟,不同参数化方案之间的差异较小,但是YSU方案在一定程度上高估了机械湍流,导致局地湍流混合偏强,从而影响了其对稳定边界层的模拟能力.  相似文献   

川滇菱形块体东边界库仑应力演化及强震发生概率估算          下载免费PDF全文

徐晶  邵志刚  刘静  季灵运 《地球物理学报》2019,62(11):4189-4213

本研究基于分层黏弹介质模型,考虑强震或大地震同震位错、震后黏滞松弛及主断层段震间构造应力加载三方面效应,给出1480年以来,川滇菱形块体东边界鲜水河断裂带、安宁河断裂带、则木河断裂带和小江断裂带共20个断层段由三方面效应引起的累积库仑应力变化随时间的演化,分析强震间相互作用和强震发生的应力累积背景,定性分析各断层段的地震危险性.同时,分别采用现今台网地震目录和川滇菱形块体东边界各断层段强震复发间隔两种资料,定量计算2030年各断层段的强震发生概率;并基于摩擦本构理论,将周边强震引起的库仑应力变化量作为应力扰动,修正强震发生概率的计算结果.各断层段累积库仑应力演化的结果表明,鲜水河断裂带中部八美段、色拉哈段及南部磨西段、安宁河断裂带冕宁-西昌段、小江断裂带北部巧家-东川段和南部建水段的累积库仑应力显著增加.修正的强震发生概率计算结果显示,鲜水河断裂带中部八美-色拉哈-康定一带、安宁河断裂带冕宁-西昌段、小江断裂带南部华宁-建水一带强震发生概率较高,地震危险性值得关注.本研究基于库仑应力演化计算定性分析强震危险性的同时,基于摩擦本构律理论,结合地震引起的应力扰动和强震发生背景,定量计算修正的强震发生概率,为川滇菱形块体东边界强震危险地点及中长期发震紧迫程度判定提供方法和依据.  相似文献   

Estimating downwind turbulence intensity using wind and wave measurements during hurricanes     

《Applied Ocean Research》2019

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Ambient vibration based seismic evaluation of isolated Gülburnu highway bridge     

Ahmet Can Altunişik  Alemdar Bayraktar  Barış Sevim  Şevket Ateş 《Soil Dynamics and Earthquake Engineering》2011

This paper describes ambient vibration based seismic evaluation procedure of an isolated highway bridge. The procedure includes finite element modeling, ambient vibration testing, finite element model updating and time history analysis. Gülburnu Highway Bridge located on the Giresun–Espiye state highway is selected as a case study. Three dimensional finite element model of the bridge is created by SAP2000 software to determine the dynamic characteristics analytically. Since input force is not measured, Operational Modal Analysis is applied to identify dynamic characteristics. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to obtain experimental dynamic characteristics. Analytical and experimental dynamic characteristic are compared with each other and finite element model of the bridge is updated by changing of material properties to reduce the differences between the results. Analytical model of the bridge after model updating is analyzed using 1992 Erzincan earthquake record to determine the seismic behavior. EW, NS and UP components of the ground motion are applied to the bridge at the longitudinal, transverse and vertical directions, respectively. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of highway bridges. Maximum differences between the natural frequencies are reduced averagely from 9% to 2% by model updating. It is seen from the earthquake analyses that friction pendulum isolators are very effective in reducing the displacements and internal forces.  相似文献