Rock resistance to erosion: Some further considerations     

Paul C. Augustinus 《地球表面变化过程与地形》1991,16(6):563-569

Rock resistance to erosion is an often described factor in geomorphic studies, and is generally considered to strongly influence the shape of erosional landforms. However, the property of the rock mass that enables it to resist erosion is rarely considered, and its measurement is rarely justified and assessed adequately. Allison (1988, 1990) examined the intact strength properties of several types of carbonate rocks and considered that dynamic Young's modulus is a good indicator of rock material strength for geomorphic purposes, and cast doubts on the reliability of Schmidt hammer tests for this purpose. Alternative approaches to rock characterization from the view point of evaluating rock intact strength are considered.  相似文献   

地震活动的分形特征及其对地震预测的意义   总被引：3，自引：0，他引：3  

朱传镇  安镇文 《地震研究》1991,14(1):73-86

岩石破裂是一个自相似过程,地震作为地壳岩石破裂的结果,它在时间和空间上的分布具有分形结构。基于系统科学和分形几何学的观点,本文采用标度变换法和嵌入空间法,分别研究了唐山7.8级、海城7.3级和松潘7.2级地震前后地震活动时、空分布的分维数,同时分析了宁夏灵武5.5级震群和澜沧5.0级前震序列的时间分维随时间的变化特征。初步结果表明:大震后余震的分维数明显增大,无标度区范围减小,展示了震后地震活动随机干扰背景增强！前兆性地震序列的时间分维数相对偏低,有序性增加。此外,文中还研究了单轴压缩下岩石破裂声发射序列的分形特征,结果表明,声发射序列亦具有自相似性,在岩石破坏过程中,声发射序列的分线数随时间的变化不是单调的。最后,籍助于“耗散结构理论”的基本概念,简要地探讨了地震时间、空间分维与地震活动熵的关系。提出了地震时、空分维作为表征地震孕育系统演化过程的序参量之一,应用于地震预测的可能途径及需要进一步研究的若干问题。  相似文献   

Ferromanganese rock varnish in north Norway: A subglacial origin   总被引：1，自引：0，他引：1  

W. Brian Whalley  Anne F. Gellatly  John E. Gordon  James D. Hansom 《地球表面变化过程与地形》1990,15(3):265-275

A thin, dark brown rock varnish is described from ice-smoothed bedrock on the forefield of a glacier in North Norway. It occurs only in narrow strips (ca 100 mm or less wide) which run roughly parallel to the ice front and along the top edges of small treads of a series of bedrock steps. The varnish is hard, thin (< 10 μm) and consists of an iron/manganese deposit, greatly enriched in these elements compared with the composition of the underlying gabbroic bedrock. It is suggested that the varnish formation is due to localized changes in Eh/pH conditions in subglacial regelation ice and meltwater at the top of the bedrock steps. These changes may be due to CO₂ and/or O₂ degassing from water held at higher pressures under the ice than in cavities downstream where the ice is decoupled from the bedrock. Glacier retreat rates indicate that the varnish has remained exposed subaerially at the surface for about twenty years, and its restricted occurrence suggests that it is not of biological origin but rather is essentially authigenic. Possible subglacial origins for associated iron and silica precipitates are also suggested.  相似文献   

Rock mechanics applied to shaft pillar mining     

J. C. Johnson  S. A. Orr 《Geotechnical and Geological Engineering》1990,8(4):385-392

Summary The Bureau of Mines is investigating methods for evaluating and optimizing shaft designs for deep metal mines. This paper describes one such project at the Homestake Mine in Lead, SD. To determine a safe approach for the extraction of ore from the Ross Shaft pillar at Homestake, a basic rock mechanics approach has been taken that involves laboratory testing, field measurements, and computer modelling. The results of the study show that ore bodies in the Ross pillar can be mined safely and that the shaft will remain in elastic rock. On the basis of this work, other mines can develop finite-element modelling to evaluate the stability of mine openings and increase resource recovery.  相似文献   

Perturbed earth processes due to thermally induced deformation in a discontinuous granite mass     

A. M. Awadalla 《Geotechnical and Geological Engineering》1990,8(4):319-331

Summary The effect of thermally induced stress on fractured granite is considered, using mathematics to solve an engineering problem that includes: (1) physical information translated into a mathematical form; (2) a mathematical model proposing a solution of the problem and (3) interpretation of the solution in physical terms.This procedure, applied to an engineering problem demonstrates that theory and its physical applications are related.  相似文献   

京西煤矿粉尘中二氧化硅赋存状态与展布的研究          下载免费PDF全文

李璃 《地质科学》1992,(1):78-88

矿区粉尘中危害人体健康的核心物质是 SiO₂。SiO₂有两种赋存状态,即游离态SiO₂和结合态 SiO₂,这两种赋存状态的 SiO₂对人体的危害程度不同。本文对京西王平村、大台和门头沟煤矿的研究中得知,三个煤矿的粉尘中均含有游离态 SiO₂和结合态 SiO₂,但二者含量不同。本研究为粉尘的治理提供了科学依据。  相似文献   

广西金牙金矿床形成条件浅析   总被引：3，自引：0，他引：3  

李福春 《矿产与地质》1992,6(1):35-42

文章分析了与金牙金矿矿床形成有关的岩性、构造和岩浆岩;探讨了金的来源、活化条件和迁移形式;利用地质地球化学热力学计算了成矿的物理化学参数。  相似文献   

Ten year remeasurement of chemical denudation on a magnesian limestone hillslope     

S. T. Trudgill  R. I. Ferguson  J. Ball  R. W. Crabtree  R. Gent 《地球表面变化过程与地形》1994,19(2):109-114

Results from the measurement of microweight loss of Magnesian Limestone rock tablets placed at the soil–bedrock interface on a hillslope over 10 years (1982–1992) gave the same relative pattern of upslope increase in weight loss as did short-term measurements (1979–1981), but the absolute values were an order of magnitude lower (0·01–0·03 per cent per year long term and 0·1–0·6 per cent per year short term). Microweighed rock tablets may therefore give unreliable absolute rates and can only be used to indicate relative spatial differences rather than to give reliable data on temporal changes.  相似文献   

最小交叉熵谱在矿震井水位资料中的应用          下载免费PDF全文

赵明  黄积刚  郑治真 《地震工程学报》1994,16(2):29-35,49

文中简述了最小交叉熵谱原理，并用模拟资料检验了最小交叉熵谱计算程序，最后用最小交叉熵谱方法分析了矿震井水位资料。结果表明，矿震井水位资料的最小交叉熵谱中，除了日变化的２Ｈ＿ｚ以外，在震前几小时到几天中均出现８Ｈ＿ｚ的高频分量，这是一般的谱分析方法无法得到的。本文提出的方法为矿震预测提供了新的路径。  相似文献   

岩石边坡稳定性层次类比评价方法   总被引：6，自引：0，他引：6  

吕小平 《工程地质学报》1994,2(1):54-61

本文从分析影响边坡稳定性因素的构成关系入手,根据边坡岩体的地质特征,提出了分类层次结构及其权重体系的表征、边坡稳定性排序和根据工点之间的综合相似关系给出边坡稳定性类比评价方法。这种方法能更充分地表达边坡岩体的各种特征及其相互间的关系与联系,统一了可定量的数值数据与不可定量的等级数据,排除了不相关因素的干扰。它以实际典型地质模型为评价基础,能从总体上把握岩体的主要特征,因而得出的评价结果是可靠的。  相似文献