Analysis of triaxial ellipsoids: Their shapes, plane sections, and plane projections

A method is presented for the determination of a triaxial ellipsoid (such as a strain ellipsoid)from three nonparallel plane sections of the ellipsoid. The sections need be neither orthogonal nor central sections of the ellipsoid. Measurement errors are used to adjust the observed plane ellipses so that they are exact sections of the nearest true ellipsoid, whose dimensions and orientation are then found by solution of a system of six linear equations. A solution of the inverse problem is also presented: given a triaxial ellipsoid with known orientation, to determine the shape and orientation of the ellipse on a plane section. The problem is solved by expanding the equation of an ellipsoid with rotated coordinates, then setting one dimension to zero. Also, a method is presented for the projection of a triaxial ellipsoid onto a plane surface. This is solved by taking the derivative of the ellipsoid equation in the direction of the normal to the plane surface.     

Estimation of seismic hazard with allowance for noncircular isoseismals of arbitrary orientation

A new mathematical model describing the field of macroseismic intensity has been elaborated. It is based on elliptic isoseismals. The orientation of the main axes of elliptic isoseismals depends on the direction of stretching of the main geological structures on the investigated territory.The new model of a macroseismic field was applied to the territory of Eastern Uzbekistan. Some results of macroseismic investigations of the effect of large regional earthquakes were used as initial data.A noncircular model of a macroseismic field was introduced into the integral of the seismic shakability of Riznichenko and, according to the model, a macroseismic shakability map for the territory of Eastern Uzbekistan was computed in isolines of the long-term mean return period of vibrations for the intensity I 8.Paper presented at the 21st General Assembly of the European Seismological Commission, Sofia, 1988.     

用空间解析几何法绘制矿脉迹线

利用空间解析几何法展绘地质设计中的中段及剖面地质图上的矿脉的理想迹线,将传统的图解推测矿脉法上升到定量计算推测法,为用计算机绘制地质设计图件打下基础。     

解析几何法在倾斜结构面地质图编制中的应用

工程地质图是表明各种地质及水文地质现象的一种图件,它是否能客观地反映实际情况与制图方式极为密切。本文就一些传统的地质制图法与解析几保法在倾斜结构面的地质图编制中的应用方法进行对比,认为解析几何法在倾斜结构面地图编制中的应用方法蝇一种简单而行之有效的制图方法。     

采用RNG紊流模型计算静止环境中圆形负浮力射流

基于RNG方法的κ-ε湍流模型,运用混合有限分析算法对静止环境中圆形负浮力射流进行数值模拟。从射流的最大入侵高度、流速矢量图、温度等值线、湍动能等值线、横断面上的流速和温度分布以及轴线上温度变化等方面与有效的试验资料进行了较为全面的对比验证。两者的良好吻合表明,基于RNG方法的紊流模型和混合有限分析法的结合能较好地模拟变密度流动。     

确定板状隐伏矿体产状的一种几何方法及应用

隐伏矿体、缺乏产状标志的矿体,在地质勘查中难以用通常方法确定矿体产状和真厚度。笔者从解析几何的角度,介绍了一种直观地解决此类问题的几何方法,及其在以往勘查中得到的相关技术应用。     

五马箐组变质杂岩岩石化学特征及地质意义

米易海塔地区五马箐组地层,前人争议较多。争论焦点主要围绕其时代归属及成因问题。通过野外实际工作,发现五马箐组片岩、片麻岩内有大量长英质脉体。据其空间展布、岩石学及稀土元素特征,判定具混合岩特征。因此认为五马箐组地层岩石组合与河口群地层存在一些可比性,时代早于会理群,晚于康定群,属区域动热变质作用及混合岩化作用形成。     

层序地层学模拟研究进展及趋势

模拟层序地层学是层序地层学理论重要的研究手段之一,在国外该项技术较为成熟.层序地层计算机模拟软件采用的算法主要有扩散算法、流体流动算法、几何控制沉积算法、经验数值逼近算法、沉积物搬运的构造校正算法.目前,国外学者对以海平面升降、构造沉降和沉积物供应为主控因素的层序地层概念模拟的适用性提出了质疑,并对层序控制因素的多样性和不确定性进行了深入的研究.结合当前的研究进展,提出了层序控制因素的"多变量系统"观点,将层序的控制因素分为综合变量和独立变量,进一步指出如果假设综合变量为独立变量,则可以简化层序模拟,假设越多,模拟越简单,但模拟结果越粗略;要使模拟结果真实地反映实际地层特征,就要尽可能采用独立变量.     

The petrography,structure and mechanical behaviour of coals

Summary The objective of this study is to determine the parameters which influence coal's mechanical behaviour. The two coals examined (HBL, Simon, France and Barro Banco, Brazil) structurally originated from different deposits. The differences are readily explained by the contrasting composition of vitrain, clarain, durain and fusain. Their mechanical behaviour is linked to their petrographical composition. The Lorrainain coal behavioural pattern was evaluated. It is elastobrittle or elastoplastic with progressive failure. Brazilian coal behaves according to a pattern of elastoplastic with progressive failure or perfect elastoplastic.     

新疆图拉尔根基性-超基性岩体中基性包体岩石地球化学特征及其成岩过程

新疆哈密图拉尔根铜镍硫化物矿床是东天山黄山-镜儿泉韧性剪切带上的一个典型岩浆熔离-贯入型矿床。在图拉尔根岩体中的角闪辉橄岩相中发育了一些基性包体,这些包体尺寸在几到几十厘米之间,岩性主要为辉长岩、斜长岩,辉长岩包体含矿性好,而斜长岩包体不含矿。通过岩相学观察发现,包体与寄主岩在矿物种类、含量、蚀变类型及程度以及矿物接触交代关系和生成顺序上存在较大的差异,并且,两者存在截然的接触边,该接触边以鳞片状绿泥石为主。哈克图解和SiO₂与不相容元素La、Nd、Zr、Yb的相关性图解都显示图拉尔根基性-超基性岩体样品具有很好的相关性,而包体样品则不具有明显的相关性,指示了岩浆混染作用在包体成岩中的重要作用。微量元素地球化学特征显示包体和图拉尔根岩体均具Nb、Ta亏损,这可能是陆壳混染作用的结果,或源区存在俯冲的洋壳物质。此外,包体中K、Pb、Sr、P含量非常高,暗示后期流体作用较强;包体的Nb/U、Ce/Pb值都更接近大陆地壳的值,这些都说明陆壳混染的可能性较高,或存在较强的流体迁移作用。     

10块新疆哈密沙漠陨石的类型及其岩石矿物学特征

沙漠是除南极地区之外的另一陨石样品的主要来源地。我国拥有面积辽阔的沙漠,为陨石的收集提供了有利的地理条件。2013年5月,在首次新疆库姆塔格沙漠陨石考察中,发现并收集到46块陨石样品,确定了3个陨石富集区:Hami、Alatage Mountain(AM)和Kumtag。对其中的10块代表性陨石样品进行了矿物岩石学研究,在此基础上确定了它们的化学群、岩石类型、冲击变质程度和风化程度。10块库姆塔格陨石均为普通球粒陨石,其中1块样品Kumtag014(Fa摩尔百分比为9.1~48.3,相对标准偏差PMD为51.0;Fs摩尔百分比为2.8~30.3,PMD为54.2)属于非平衡型L群。依据橄榄石Fa的PMD将其进一步划分为3.4亚型,属于相当原始的球粒陨石样品。另外9块经历了明显的热变质作用,为5型普通球粒陨石,包括7块L群(Fa22.6~25.9,Fs 17.6~21.4)和2块H群(Fa 18.2~20.8,Fs 16.0~17.8)。这些陨石的冲击变质程度:5块S3型,4块S2型,1块S1型;风化程度:3块W1型,6块W2型,1块W3型。     

裂纹方向对隧道稳定性影响规律的研究

采用模型试验和数值模拟方法,研究单轴压缩载荷下带裂纹直墙拱形隧道在不同的裂纹面与隧道垂直边墙之间的夹角 时围岩损伤破坏规律。试验采用水泥砂浆制作成具有不同夹角 的直墙拱形隧道模型,养护30 d后进行加载。数值模拟采用混凝土损伤塑性模型,计算出隧道周边各点的应力和裂纹尖端的应力强度因子,与模型试验结果吻合较好。结果表明,拱肩处的裂纹会降低隧道的整体稳定性及强度,在裂纹尖端及侧壁产生很大的应力集中,但随着 角度的变化,强度降低的程度有所不同;当 = 60?和 = 130?时,裂纹对其整体稳定性及强度的影响最大,其裂纹尖端的应力集中现象最为明显,而且破坏应力峰值仅为无裂纹模型的40.9%和41.8%。     

计算机勘探模拟系统的剖面图交互式编辑子系统

计算机的勘探模拟系统在国外已进入实用阶段。目前我们正在做这方面的尝试。在初期设想的计算机勘探系统中很多是在剖面图上进行的,所以剖面图的交互式编辑子系统是整个系统核心的部分,它的主要设计思想是用户通过计算机键盘操作、用类似手工的方法在计算机屏幕上画出一张供自己使用的地质剖面图,并且还有修改、删除、存贮等功能,使用户感到直观、灵活、方便且易于比较。     

地震采集观测系统设计及图形绘制软件的研制和使用

这里主要研究地震采集观测系统设计和图形绘制的计算机软件实现问题。到目前为止,许多的地震数据处理软件包以及专门的观测系统设计软件等都能够实现观测系统图形的显示与输出。但这些观测系统图形基本上是极为简单的显示,对图形不能进行一些个性化的设置,而能够真正用于野外队绘制观测系统成果图的软件却没有,观测系统图形仍然处于手工绘制的阶段。鉴于这种情况,利用VISUAL C 6.0研制了一个观测系统设计和图形绘制软件。该软件绘制的图形不但能基本满足目前观测系统的成图规范,还能根据需要进行合理化的设置。从而可以将观测系统图形的手工绘制转为计算机绘制,并方便地利用打印机或用绘图仪输出,大大提高了绘制观测系统的效率和准确性。经实际应用效果较好。     

计算机模拟引擎及其在铀成矿过程模拟中的应用研究

本文介绍了计算机模拟引擎的设计与开发 ,铀成矿过程模拟的实施步骤 ,并对其在伊犁盆地南缘的应用作了探讨。     

Conditional Simulation of Complex Geological Structures Using Multiple-Point Statistics

In many earth sciences applications, the geological objects or structures to be reproduced are curvilinear, e.g., sand channels in a clastic reservoir. Their modeling requires multiple-point statistics involving jointly three or more points at a time, much beyond the traditional two-point variogram statistics. Actual data from the field being modeled, particularly if it is subsurface, are rarely enough to allow inference of such multiple-point statistics. The approach proposed in this paper consists of borrowing the required multiple-point statistics from training images depicting the expected patterns of geological heterogeneities. Several training images can be used, reflecting different scales of variability and styles of heterogeneities. The multiple-point statistics inferred from these training image(s) are exported to the geostatistical numerical model where they are anchored to the actual data, both hard and soft, in a sequential simulation mode. The algorithm and code developed are tested for the simulation of a fluvial hydrocarbon reservoir with meandering channels. The methodology proposed appears to be simple (multiple-point statistics are scanned directly from training images), general (any type of random geometry can be considered), and fast enough to handle large 3D simulation grids.     

Petrography and temporal changes in petrofacies of deep-marine Ainsa–Jaca basin sandstone systems, Early and Middle Eocene, Spanish Pyrenees

A petrographic study of 157 samples from the Early to Middle Eocene deep-marine sandy systems, Ainsa–Jaca basin, Spanish Pyrenees, shows that each system has a characteristic petrofacies. Three main petrofacies are recognized. Petrofacies 1 sandstones comprise mainly siliciclastic grains (≥80%), subordinate terrigenous carbonate grains and negligible intrabasinal grains. Petrofacies 2 hybrid arenites are characterized by significant amounts (≥10%) of intrabasinal carbonate grains. Petrofacies 3 calcilithites contain relatively abundant (≥10%) extrabasinal carbonate grains. On the basis of these petrofacies, a revised correlation of the sandy systems is proposed between the more proximal Ainsa basin, and the more distal Jaca basin sediments, now separated by the Boltaña anticline, across which it is impossible to actually trace out individual beds or sandstone packages between both basins. The arenite composition in the Ainsa and Jaca basins is interpreted as being controlled mainly by synsedimentary tectonic processes that led to changes in sediment sources during basin evolution.     

基于多尺度直剪试验的岩石模型结构面抗剪强度特征研究

开展岩石模型结构面抗剪强度特征的多尺度（尤其大尺寸）直剪试验研究对于理解岩石结构面力学特性具有重要的理论价值和实践意义。首先,基于多尺度直剪试验仪(MSJ-DST),对20 cm×20 cm、40 cm×40 cm、60 cm×60 cm、80 cm×80 cm和100 cm×100 cm的岩石模型结构面试样采用法向应力分别为200～1 000 kPa进行直接剪切试验;然后,研究不同尺寸岩石模型结构面抗剪强度的特征。结果表明：不同法向荷载作用下模型的受力变形特点相近,峰值剪切位移总体上随着某一数值附近上下浮动;在同一法向应力作用下,不同尺寸结构面试样的峰值抗剪强度表现出在某一数值附近上下浮动的特征,残余抗剪强度则表现出随尺寸的增加有小幅度增加;5级法向应力作用下,不同尺寸的峰值抗剪强度和残余抗剪强度随着法向应力的变化规律均近似相同,抗剪强度残余值与峰值的比值随着法向应力的增大逐渐增大并趋于稳定。     

渗滤脉状矽卡岩成岩过程的计算机模拟

用多相多组分平衡分析了个旧锡矿区渗滤脉矽卡岩形成的机理，以该理论为基础设计的计算机程序模拟了这类矽卡岩脉的成岩过程。结果表明，花岗岩饱和热液成分不同，碳酸盐岩类型不同，通过模拟可以得到不同类型的矽卡岩及脉状矽卡岩的对称状矿物分带。     

浙江多色青田石岩石地球化学特征及成因

多色青田石是浙江青田石中的一个重要品种,具颜色丰富、纹理多变的特点。通过岩相学观察、X射线粉晶衍射物相分析、全岩主量及微量元素和同位素地球化学分析,对多色青田石的岩石学特征、矿物成分、类型划分进行详细研究,并论证了多色青田石的成矿物质、成矿流体来源及成因。研究表明:多色青田石按主要组成矿物划分属于叶蜡石型青田石和绢云母型青田石;其颜色主要与组成矿物中Fe、Ti、Cr、Mn致色元素的类型和含量有关,其次与赤铁矿(褐铁矿)浸染组成矿物的微晶间隙和充填微裂隙有关。多色青田石的成矿母岩为中酸性火山岩,成矿流体来源与大气降水有关。多色青田石主要由早期充填成因的叶蜡石矿物和晚期由中低温热液蚀变改造早期叶蜡石形成的绢云母矿物构成,是多期多阶段热液蚀变交代成矿作用的产物,多色青田石中常保留高温矿物红柱石。