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1.
在褶皱形态的分形分析基础上，利用分形理论和褶皱的岩石力学成因理论推导出了褶皱的分数维（Ｄ）与岩层厚度（ｈ）和粘度（μ）的关系式，即找到了褶皱分形分布的岩石力学成因机制，在相同的构造应力场条件下，岩层的厚度和粘度越小，则越易产生较复杂的褶皱，即褶皱的分数维越大，因此，利用褶皱的分形测量，可以定量了分析褶皱形成的岩石力学性质，这是分形研究从形态研究到机制研究的一种探索。 相似文献
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含煤岩系变形规律的研究,对煤炭资源评价和开采、煤矿瓦斯灾害预测、煤层气的可开发性评价具有指导意义。基于含煤岩系的岩体结构是控制其变形的基础因素这一前提,以岩体力学和分形几何学基本理论为指导,提出取决于岩石杨氏模量和泊松比的岩体强度因子和取决于岩层厚度的分形维数两个参数,以断层发育的安阳双全井田、褶皱发育的沁水盆地煤层气开发区及滑动构造发育的荥巩谷山井田为例,系统探讨了岩体结构对含煤岩系变形的控制作用。研究表明,低强度因子和厚层岩层较多的分形维数低值区,含煤岩系以韧性变形为主,多形成褶皱,煤体变形程度深,为瓦斯灾害严重区和煤层气难以开发区;高强度因子和厚层岩层较少的分形维数高值区,含煤岩系以脆性变形为主,多发育断层,构造煤难以区域展布,只分布在断层附近。可见含煤岩系变形不仅与岩体强度有关,而且受岩层厚度的控制。统计层段内刚性岩层的存在增加了岩体强度,岩层复杂程度的增加同样提高了岩体强度。岩体力学和分形几何学的引入,为煤岩体变形行为和程度的描述和预测提供了一种新途径。 相似文献
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褶皱的分形模拟 总被引：1，自引：0，他引：1
褶皱的定量描述是构造地质学的一个基本问题。利用褶皱分形模拟和分类的方法可以定量描述不同类型的复杂褶皱样式。分形理论能发现自然界中常见的、不稳定的、非线性和不规则的复杂现象中的内在规律。它研究自然界中没有特征长度的形状或集合的自相似性,其形状或集合的复杂程度可以用幂函数的指数D表示,这里的D就是分数维,即分形的维数。根据自然界褶皱具有分形样式的性质,利用分形插值方法模拟褶皱的形态和样式来定量描述不同的褶皱。分形插值实际上是一个建立分形插值函数的过程。根据已知的3个或4个点即插值点坐标值(x_n、y_n)就可以取不同d值利用分形插值程序建立 相似文献
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利用石香肠恢复能干层原始厚度的等面积法 总被引：4，自引：1，他引：3
在恢复岩层古环境、计算岩石流变学参数时常需要岩层的原始厚度.利用在褶皱地区伴生的肿缩石香肠可恢复岩层的原始厚度.经过沉积、压实作用以后,岩层压实率趋近最终压实率,岩石中矿物颗粒骨架基本上保持不变,则岩层体积保持不变.褶皱一般是受到垂直岩层或平行岩层作用力而形成的,肿缩石香肠在褶皱轴向(b轴)上变形通常很微小,根据体积不变的假设,则石香肠体在褶皱横向剖面(ac面)上变形前后的面积应是相等的,以此来恢复岩层的原始厚度.为了求解肿缩石香肠横向剖面面积,对其边界进行拟合、积分,发现它相当于一些梯形面积之和.运用此方法进行模拟实验并对铁山地区进行计算,并把计算结果与肿缩石香肠的最大厚度比较,发现它更能反映真实情况. 相似文献
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为了弄清褶皱构造形成过程中应力场的分布及动态演化状况,运用弹性力学理论对褶皱构造形成过程中的应力场进行了分析并对其动态演化进行了探索。通过分析给出了单一岩层褶皱启动时应力场的解析式;根据解析式求出了褶皱波长与岩层厚度、刚度模量之间的关系,从而揭示了褶皱等距性的成因;同时研究了褶皱驱动应力与岩层厚度、刚度模量以及褶皱波长之间的关系,从而指出褶皱作为"古地应力记录仪"用以测量古地应力的可能性。通过对不同结合状态复合岩层的分析,揭示了平行褶皱、相似褶皱、不协调褶皱的成因;在单一岩层褶皱启动时应力场解析式的基础上,提出了能体现褶皱应力场演化状况的解析式并做了部分求证,进而对褶皱应力场的演化做了分析。 相似文献
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深部开采上覆岩层采动裂隙网络演化的分形特征研究 总被引：2，自引：0，他引：2
借助相似模拟材料模型试验,模拟了在深部开采条件下上覆岩层采动岩体裂隙分布状态,运用分形几何理论研究了采动岩体裂隙网络分形维数随开采宽度、采场矿山压力、岩层沉降的动态演化规律,并分析了断层对采动岩体裂隙网络分布演化的影响以及采动岩体裂隙网络在三带的分布特征。结果表明：随开采宽度增加,采动岩体裂隙网络分形维数呈现总体增大趋势,在断层影响下表现出降维特点;分形维数与超前工作面压力和岩层沉降均具有非线性关系;三带采动岩体裂隙网络均具自相似性,冒落带、裂隙带、弯曲带分形维数比为1.082 3:1.139 4:1。 相似文献
7.
川东南地区是我国南方重要的天然气探区,气藏分布受与该区的褶皱带构造演化密切相关.该区褶皱带呈现马尾状平面构造样式,对于这种特殊褶皱样式的形成机制存在不同的观点.构造物理模拟是研究构造形成机制的有效手段.为此,笔者在对该区马尾状褶皱特征详细分析的基础上,设计了5组模型,分别考虑边界几何形态、地层流变学结构、韧性层粘度和基底摩擦系数等4个因素,对该褶皱带的形成机制开展系统研究.结果表明:（1）该区马尾状褶皱带的形成与川东华蓥山断裂和齐岳山边界断裂形态关系密切;（2）脆/韧性地层厚度比和脆性层的厚度差对褶皱波长和样式具有重要控制作用;（3）适当的基底摩擦力是形成马尾状褶皱带的重要条件;（4）四川盆地内部、川东地区和湘鄂西地区基底流变学强度差异对该区马尾状褶皱带也具有重要影响. 相似文献
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假定弯曲流动褶皱的多层岩层是由多个各向同性的弹性薄层粘合而成的非均匀板,基于弹性薄板理论,研究了褶皱岩层仅受纯弯曲作用时褶皱中和面的位置的确定问题,得出了用各岩层弹性模量、泊松比和岩层厚度表示的褶皱中和面位置公式。结合贵州六盘水煤田涝河向斜,计算了涝河向斜褶皱中和面处于龙潭组9号煤层的底板岩层细砂岩中,距茅口组底部966 m, 煤岩层距离中和面越近,褶皱构造对其瓦斯赋存影响越少,使得该处的瓦斯含量与翼部差值就越小。研究成果对煤层气开发及煤与瓦斯突出防治具有一定的指导作用。 相似文献
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褶皱冲断带油气资源丰富,统计表明全球探明油气储量约14%分布在褶皱冲断带。自从1815年地质学家第一次以模拟实验的方式验证了褶皱形成于岩层遭受水平挤压变形的二百多年来,针对褶皱冲断带的物理模拟实验研究无疑是最卓有成效的研究领域方向之一。本文从追溯早期模拟实验先驱,到近二十年来国内外相关研究进展综述,着重分析和评述物理模拟实验研究对于前陆褶皱冲断带构造理论发展的主要贡献。强调造山带临界楔体理论以及基底滑脱层强度、流体超压和变形岩层内聚强度等对构造变形过程的控制作用。主要介绍的实验性标志成果有：(1)褶皱冲断带构造变形的生长规律;(2)褶皱冲断带的构造变形机制;(3)褶皱冲断带中构造变形的主控因素。我们的目的是提供引人入胜的物理模拟实验研究成果,吸引更多现在和未来的研究人员理解和重视物理模拟工作,借助日益进步的实验装置和技术方法,促进盆地构造研究在学科发展道路上,一步步实现从定性走向定量、从二维走向三维、从几何学和运动学走向动力学的飞跃。 相似文献
11.
HOU Guiting 《《地质学报》英文版》2009,83(3):544-549
Abstract: The fractal dimensions of folds are related to layer thickness and viscosity of the multilayer. This paper discusses how the thickness, viscosity, and anisotropic degree affect the rheological deformation of fractal folds in multilayers. The number of layers, their thicknesses, viscosities, and anisotropic degree of multilayers cooperate to affect the rheological deformation of folds, which is not controlled by a single rheological factor. A greater anisotropic degree of multilayers is favorable to develop the more complex and disharmonious fractal folds. 相似文献
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On the practice of estimating fractal dimension 总被引：11，自引：0，他引：11
Coastlines epitomize deterministic fractals and fractal (Hausdorff-Besicovitch) dimensions; a divider [compass] method can be used to calculate fractal dimensions for these features. Noise models are used to develop another notion of fractals, a stochastic one. Spectral and variogram methods are used to estimate fractal dimensions for stochastic fractals. When estimating fractal dimension, the objective of the analysis must be consistent with the method chosen for fractal dimension calculation. Spectal and variogram methods yield fractal dimensions which indicate the similarity of the feature under study to noise (e.g., Brownian noise). A divider measurement method yields a fractal dimension which is a measure of complexity of shape. 相似文献
14.
The infinitesimal and finite stages of folding in nonlinear viscous material with a layer-parallel anisotropy were investigated using numerical and analytical methods. Anisotropy was found to have a first-order effect on growth rate and wavelength selection, and these effects are already important for anisotropy values (normal viscosity/shear viscosity) < 10. The effect of anisotropy must therefore be considered when deducing viscosity contrasts from wavelength to thickness ratios of natural folds. Growth rates of single layer folds were found to increase and subsequently decrease during progressive deformation. This is due to interference between the single layer folds and chevron folds that form in the matrix as a result of instability caused by the anisotropic material behaviour. The wavelength of the chevron folds in the matrix is determined by the wavelength of the folded single layer, which can explain the high wavelength to thickness ratios that are sometimes found in multilayer sequences. Numerical models including anisotropic material properties allow the behaviour of multilayer sequences to be investigated without the need for resolution on the scale of individual layers. This is particularly important for large-scale models of layered lithosphere. 相似文献
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本文根据褶皱的白相似性特征,引用分形概念,分析褶皱的分形分布特性,并利用MichaelBamsley（1986）的分形插值理论首次模拟褶皱的复杂形态,主要利用插值点（x、y）和褶皱扰动系数d模拟各种褶皱,在此基础上,提出褶皱复杂程度的分形分类方案。这种新的分类方案即褶皱形态的传统分类名称附缀分形分类名称,解决了传统分类方法不能区分褶皱复杂性的难题。这种方法使褶皱的形态分析达到较精确的定量描述和分类,分形分类方法是对褶雏形态分类的一个补充。 相似文献
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Several structure sets (faults and folds) are characterized by their self-similarity properties. Herein, we discuss the degrees of complexity of fractures by introducing the box-counting fractal dimension of faults as a key criterion to be used in comprehensive fuzzy analysis model for evaluation of the complexity of structures. Totally, eight criteria including density, intensity, length of faults, types and box-counting fractal dimension of faults, the intersection angle between faults and coal beds, gradient coefficients, dip angles of the coal beds, and variation coefficients of dip angles of the coal seams, were used for the evaluation purpose. The grey fuzzy comprehensive assessment model was used to rank the relative importance of these criteria. Scores indicating the complexity of structure were calculated on the base of criteria values and their weights for each sub-area of the study area in the Pansan (潘三) coal mine district in the southern Anhui (安徽) Province, China. The result on the calculated complexity of structure is useful for mining planning in the study area. 相似文献
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Scale-dependent fractal dimensions of topographic surfaces: An empirical investigation, with applications in geomorphology and computer mapping 总被引：6，自引：0，他引：6
Fractional Brownian surfaces have been widely discussed as an appropriate model for the statistical behavior of topographic surfaces. The fractals model proposes that topographic surfaces are statistically self-similar, and that a single parameter, the fractal dimension, applies at all scales. This paper presents the results of empirical examinations of 17 topographic samples. Only one of these samples shows the statistical behavior predicted by the fractals model; however, in 15 of the 17 samples, the surfaces' variograms could be adequately described by ranges of scales having constant fractal dimension, separated by distinct scale breaks. For scale ranges between adjacent breaks, surface behavior should be that predicted by the fractals model; the breaks represent characteristic horizontal scales, at which surface behavior changes substantially. These scale breaks are especially important for cartographic representations and digital elevation models, since they represent scales at which there is a distinct change in the relation between sampling interval and the associated error. 相似文献
18.
高寒湖沼区水系沉积物中元素迁移富集的分形伸展机制 总被引：1，自引：1，他引：1
孙忠军 《物探化探计算技术》2005,27(3):246-249
水系沉积物中成矿元素迁移富集的动力学机制是复杂性科学的研究课题。利用分形理论研究空间结构复杂性特征,适宜于元素分散过程的动力学研究。从元素迁移过程的分形特征揭示出元素分散过程的分形伸展机制。并在进一步研究了元素粒级层分维特征后,得出了成矿元素物理空间结构的复杂性特征和相互联系。研究成矿元素相态层分维和其间非线性关联,揭示出成矿元素分散过程分形伸展的涌现原因。 相似文献
19.
Fractal models for predicting soil hydraulic properties: a review 总被引：33，自引：0，他引：33
Modern hydrological models require information on hydraulic conductivity and soil-water retention characteristics. The high cost and large spatial variability of measurements makes the prediction of these properties a viable alternative. Fractal models describe hierarchical systems and are suitable to model soil structure and soil hydraulic properties. Deterministic fractals are often used to model porous media in which scaling of mass, pore space, pore surface and the size-distribution of fragments are all characterized by a single fractal dimension. Experimental evidence shows fractal scaling of these properties between upper and lower limits of scale, but typically there is no coincidence in the values of the fractal dimensions characterizing different properties. This poses a problem in the evaluation of the contrasting approaches used to model soil-water retention and hydraulic conductivity. Fractal models of the soil-water retention curve that use a single fractal dimension often deviate from measurements at saturation and at dryness. More accurate models should consider scaling domains each characterized by a fractal dimension with different morphological interpretations. Models of unsaturated hydraulic conductivity incorporate fractal dimensions characterizing scaling of different properties including parameters representing connectivity. Further research is needed to clarify the morphological properties influencing the different scaling domains in the soil-water retention curve and unsaturated hydraulic conductivity. Methods to functionally characterize a porous medium using fractal approaches are likely to improve the predictability of soil hydraulic properties. 相似文献