共查询到19条相似文献，搜索用时 312 毫秒
1.
2.
近5年来,我国广泛地开展了天然断层泥力学性质的研究,并取得了明显的进展。在实验中,对天然断层泥的多种力学参数进行了研究,同时还在现场进行了某些力学量的测量,取得了系统的实验数据。这些数据对活动断裂的研究具有参考价值。本文简要地介绍了我国天然断层泥力学性质研究的特点及其进展情况,并提出了今后进行断层泥研究应考虑的几方面的问题。 相似文献
3.
4.
通过济南辉长岩双剪摩擦实验,笔者研究了非粘土断层泥带厚度随断层滑移的变化特征及主要影响因素。结果表明:非粘土断层泥的形成过程具有明显的分段特征。在断层演化的中期阶段,非粘土断层泥带厚度与断层错距呈明显的线性关系。该关系的建立,为从构造物理角度反演断层错距提供了一个可尝试的途径;凹凸体作用的结果,为非粘土断层泥的形成提供了丰富的物质来源,同时,凹凸体的几何尺度又控制着断层泥带的极限厚度。这一发现不仅对于研究断层泥的形成过程,而且对于研究断层发育的后期阶段的摩擦滑动性状都有重要意义。 相似文献
5.
地震时大部分形变发生在断层带内的主滑动面上,断层表面形貌是断层活动的产物并随断层滑动距离而演化。断层面形貌已成为研究破裂成核作用及应力的非均匀分布、断层面凸体磨损、断层泥生成、滑润作用、抗剪强度与临界滑动距离的相关内容,因此断层面形貌研究对地震和断层力学具有重要意义。任何一个野外天然断层面露头, 相似文献
6.
在不同的压力、温度和孔隙压力下进行了含四种不同断层泥标本的强度试验。碎屑型断层泥对压力很敏感,对温度无反应,对孔隙压力的反应符合有效应力律。粘土类断层泥则对温度和孔隙压力有明显响应。这些力学性质的差别反映了具体变形机制的差别 相似文献
7.
沿新疆可可托海—二台断层采集了断层泥,分析了断层中碎屑和粘土含量的比例。在100—300Mpa围压下测定了断层泥的力学性质,并就它们与断层粘土含量和水含量的关系进行了讨论。 1931年在新疆可可托海—二台断层中部不连续段卡拉先格尔发生了8级强震,沿断层发生了十几米的右旋水平错动。由于新疆气候干旱,人烟稀少,使这个五十多年前发生的地震遗迹得以保存。在新疆地震局的协助下,1984年部分作者沿这条长达200公里的地震断层进行了野外考查,并在一些部位采集了断层泥样品。本文着重提供断层泥的性质以及不同围压下的强度。由于断层泥是断层活动的产物,但又影响断层带的力学性质,故可在分析地震发生条件时参考。 相似文献
8.
9.
本文对红河断裂带断层泥的某些基本力学性质进行了实验研究,得到红河断层泥的体积压缩模量为104巴的量级,杨氏模量为102—103巴的量级,泊松比为0.3—0.4,单轴抗压强度由数巴至数十巴,单轴抗剪强度为数巴,粘滞系数为1010—1011泊的量级,弹性波速为1.5—2.2公里/秒。对比红河断裂带南北两段断层泥的力学性质,看出南段断层泥的体积压缩模量,杨氏模量、抗压强度、粘滞系数和弹性波速比北段断层泥高。此外,南段断层泥弹性波速基本上各向同性而北段断层泥弹性波速显示出各向异性。 相似文献
10.
国内外学者的研究表明断层泥对断层滑动方式有着重要影响。断层的滑动方式又与地震的孕育和发生过程紧密联系。研究断层泥与断层滑动方式的关系是很有意义的。一、非粘土断层泥的研究 Shimamoto和Logan(1981)[1]在缩短率为2×10~(-4)cm/s,围压可高至300Mpa,室温干燥条件下的三轴装置中,研究了不同种类非粘土断层泥对砂岩模拟断层滑动方式的 相似文献
11.
5.12汶川地震同震地表破裂带在虹口八角-深溪沟一带主要出露于三叠系须家河组的炭质泥岩中,同震断层泥在颜色、结构上与老断层泥和围岩类似。通过开挖探槽,系统采样,采用粉晶X射线衍射定量分析方法,研究了同震地表破裂带的围岩、断层角砾岩、老断层泥和新断层泥的矿物成分特征。同震断层泥的主要成分为石英和黏土矿物,含微量长石和白云石;断层泥的显著特征为高黏土矿物含量,从同震断层泥、老断层泥、角砾岩到围岩黏土矿物含量依次降低,黏土矿物以伊利石和伊蒙混层为主,含微量绿泥石和高岭石,矿物组成明显比地表破裂带北段同震断层泥简单。不同颜色的同震断层泥成分略有不同,黑色断层泥中伊利石含量明显高于白色断层泥;老断层泥中含有方解石和白云石,而同震断层泥不含方解石,只含微量白云石。同震断层泥中伊蒙混层高含量表明,在本次地震错动中有富含K的流体参与。 相似文献
12.
13.
Vladimir Lyakhovsky Amir Sagy Yuval Boneh Ze’ev Reches 《Pure and Applied Geophysics》2014,171(11):3143-3157
Slip along faults generates wear products such as gouge layers and cataclasite zones that range in thickness from sub-millimeter to tens of meters. The properties of these zones apparently control fault strength and slip stability. Here we present a new model of wear in a three-body configuration that utilizes the damage rheology approach and considers the process as a microfracturing or damage front propagating from the gouge zone into the solid rock. The derivations for steady-state conditions lead to a scaling relation for the damage front velocity considered as the wear-rate. The model predicts that the wear-rate is a function of the shear-stress and may vanish when the shear-stress drops below the microfracturing strength of the fault host rock. The simulated results successfully fit the measured friction and wear during shear experiments along faults made of carbonate and tonalite. The model is also valid for relatively large confining pressures, small damage-induced change of the bulk modulus and significant degradation of the shear modulus, which are assumed for seismogenic zones of earthquake faults. The presented formulation indicates that wear dynamics in brittle materials in general and in natural faults in particular can be understood by the concept of a “propagating damage front” and the evolution of a third-body layer. 相似文献
14.
15.
David R. Scott David A. Lockner James D. Byerlee Charles G. Sammis 《Pure and Applied Geophysics》1994,142(3-4):749-775
Triaxial compression experiments were performed on samples of natural granular fault gouge from the Lopez Fault in Southern California. This material consists primarily of quartz and has a self-similar grain size distribution thought to result from natural cataclasis. The experiments were performed at a constant mean effective stress of 150 MPa, to expose the volumetric strains associated with shear failure. The failure strength is parameterized by the coefficient of internal friction , based on the Mohr-Coulomb failure criterion.Samples of remoulded Lopez gouge have internal friction =0.6±0.02. In experiments where the ends of the sample are constrained to remain axially aligned, suppressing strain localisation, the sample compacts before failure and dilates persistently after failure. In experiments where one end of the sample is free to move laterally, the strain localises to a single oblique fault at around the point of failure; some dilation occurs but does not persist. A comparison of these experiments suggests that dilation is confined to the region of shear localisation in a sample. Overconsolidated samples have slightly larger failure strengths than normally consolidated samples, and smaller axial strains are required to cause failure. A large amount of dilation occurs after failure in heavily overconsolidated samples, suggesting that dilation is occurring throughout the sample. Undisturbed samples of Lopez gouge, cored from the outcrop, have internal friction in the range =0.4–0.6; the upper end of this range corresponds to the value established for remoulded Lopez gouge. Some kind of natural heterogeneity within the undisturbed samples is probably responsible for their low, variable strength. In samples of simulated gouge, with a more uniform grain size, active cataclasis during axial loading leads to large amounts of compaction. Larger axial strains are required to cause failure in simulated gouge, but the failure strength is similar to that of natural Lopez gouge.Use of the Mohr-Coulomb failure criterion to interpret the results from this study, and other recent studies on intact rock and granular gouge, leads to values of that depend on the loading configuration and the intact or granular state of the sample. Conceptual models are advanced to account for these descrepancies. The consequences for strain-weakening of natural faults are also discussed. 相似文献
16.
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
17.
断层泥粒度成分的分形研究 总被引：10，自引：3，他引：10
用分形理论分析了断层泥粒度成分的分形结构特征，其分维在２～３之间，平均值为２．８左右。分维可作为定量描述断层泥粒度成分的参数，分维值高的断层泥，自组织程度高，其形成演化处于高级阶段。探讨了断层泥的分维及其物理力学性质指标和断层运动特征的关系 相似文献
18.
为了得到增湿后黄土围岩隧洞在地震作用下的动力特性, 基于初始弹性模量和抗剪强度指标与含水量的关系, 采用时程分析法, 对增湿情况下的黄土围岩-隧洞结构进行地震动力分析. 数值计算结果表明: 随着含水量的增加, 隧洞衬砌各部位主应力绝对值减小, 自振圆频率减小, 自振周期相应增大; 与输入的地震加速度峰值相比, 当黄土隧洞围岩含水量小于临界含水量时, 隧洞顶部加速度峰值大于输入地震加速度峰值, 大于临界含水量时则出现相反的结果; 同一含水量下, 隧洞衬砌对称部位最大、 最小主应力交替出现, 使隧洞衬砌材料发生疲劳损伤, 是隧洞衬砌破坏的主要原因. 本文研究结果可以为在不同含水量情况下黄土围岩-隧洞结构的抗震分析提供参考. 相似文献
19.
龙马溪组页岩是目前国内页岩气勘探的主要层位之一,其静态弹性性质是影响压裂效果的重要因素,而动态弹性性质则是页岩"甜点"地震预测的重要基础.但对龙马溪组页岩动、静态弹性特征相互关系及其影响因素缺少对比研究,致使运用动态弹性性质进行"甜点"预测时存在不确定性.在对龙马溪组页岩样品系统动、静态性质联合测量基础上,分析了页岩样品动、静态弹性性质的变化规律,并讨论了成岩作用与动、静态弹性性质变化规律的因果关系.研究结果表明,龙马溪组页岩上下两段成岩过程存在明显差异,致使上段页岩在结构上表现为以塑性黏土颗粒作为受力骨架,而下段页岩在结构上逐渐转变为脆性石英颗粒作为受力骨架.页岩岩石结构特征的变化控制了动、静态弹性特征的整体变化规律,表现为动、静态杨氏模量、峰值强度等随石英含量的增大表现出近似"V"型的变化形式,而与钙质含量变化呈现正相关关系,与黏土含量变化表现出负相关性.上段页岩宏观力学性质受微观石英+黏土颗粒集合体弹性性质控制,应力应变曲线表现出明显塑性段,动、静态杨氏模量比大于1.4,破裂易于发生在黏土与石英颗粒边界形成宏观单剪型破裂模式,样品脆性低,且脆性变化不受石英含量的影响.下段页岩宏观力学性质受微观石英颗粒集合体弹性性质控制,应力应变曲线表现为弹性变形,动、静态杨氏模量比小于1.4,破裂发生在石英颗粒内部形成宏观劈裂型破裂模式,样品脆性高,且脆性变化与石英含量呈明显正相关关系.研究结果可为龙马溪页气储层的测井解释和地震"甜点"预测提供依据. 相似文献