Microcracks in rocks: A review

成核 热弹性阻尼 地质学 晶界 岩体分类 静水压力 压力溶液 流体静力平衡 压力(语言学) 应力场 石英 静水应力 材料科学 粒度 变形(气象学) 热的 矿物学 复合材料 差异应力 岩土工程 机械 微观结构 哲学 语言学 化学 物理 有机化学 量子力学 有限元法 气象学 热力学
作者
Robert L. Kranz
出处
期刊:Tectonophysics [Elsevier BV]
卷期号:100 (1-3): 449-480 被引量:848
标识
DOI:10.1016/0040-1951(83)90198-1
摘要

Abstract In the past decade the number of studies about microcracks in rocks has rapidly increased. This review of recent work concentrates on microcracks in rock as separate entities, emphasizing microcrack morphogenesis, kinematics, dynamics, population statistics and observational techniques. Cracks are produced when the local stress exceeds the local strength. The local stress may be augmented by twin lamellae interactions, kink bands and deformation lamellae, stress concentrations at grain boundary contacts and around intracrystalline cavities. Local strength may be reduced along cleavage planes, along grain boundaries and along any internal surface as a result of corrosion by chemically active fluids. Dislocations appear not to be a significant factor for crack nucleation below about 500°C in silicates. Spatial and temporal changes in temperature can also induce microcracking as a result of differential thermal expansion between grains with different thermoelastic moduli and thermal conductivities. The amount of quartz in the rock has a significant effect on thermally induced microcracks because of its large and variable thermal expansivity. The application of hydrostatic pressure between 100 and 200 MPa effectively closes most cracks, but the closure may not be uniform if crack wall asperities exist. Hydrostatic pressure appears to stabilize cracks and make crack growth more difficult. The number and average size of mechanically induced microcracks is greater in rock deformed at higher pressures. The application of a deviatoric stress field on the boundaries of a rock mass results, on a microscopic scale, in a very complex stress system which greatly affects nucleation and propagation paths. The relative amount of intragranular and intergranular cracking appears to depend upon mineralogy, rock type and stress state. The vast majority of stress-induced microcracks in rocks appear to be extensional. Statistically, they are predominantly oriented within 30° of the macroscopic maximum stress direction. Crack densities increase as macroscopic deviatoric stress increases above a threshold level. Crack size distributions may be either lognormal or exponential. Fracture in rock under compressive boundary loads is a result of the coalescence of many microcracks, not the growth of a single crack. Some crack configurations are more favorable for coalescence than others. As deviatoric stress increases and rock failure is approached, the microcrack population changes spatially from random to locally intense zones of cracking. Away from the fault, the crack density dies off rapidly to the background level a few grains away. Under lesser deviatoric stresses, slow, subcritical microcrack growth can occur as a result of stress-aided corrosion at the crack tip. The rate governing mechanism may be either the chemical reaction rate or the rate at which water can get to the crack tip. Important details still remain to be worked out.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
guangyu完成签到,获得积分10
1秒前
学术老6完成签到,获得积分10
2秒前
c123完成签到 ,获得积分10
4秒前
恐怖稽器人完成签到,获得积分10
4秒前
WXR完成签到,获得积分10
5秒前
科研小白完成签到,获得积分10
5秒前
6秒前
可爱丸子完成签到,获得积分10
6秒前
皮汤汤完成签到 ,获得积分10
7秒前
JXDYYZK完成签到,获得积分10
8秒前
SYLH应助lu采纳,获得10
8秒前
Servant2023完成签到,获得积分10
8秒前
鸽子的迷信完成签到,获得积分10
10秒前
nine2652完成签到 ,获得积分10
11秒前
烂漫的睫毛完成签到 ,获得积分10
13秒前
量子星尘发布了新的文献求助10
13秒前
陈老太完成签到 ,获得积分10
14秒前
宇宇宇c完成签到,获得积分10
15秒前
zxt完成签到,获得积分10
16秒前
大橙子发布了新的文献求助10
19秒前
聪明静柏完成签到 ,获得积分10
21秒前
kimiwanano完成签到,获得积分10
23秒前
lu完成签到,获得积分10
24秒前
Profeto应助齐嫒琳采纳,获得10
25秒前
26秒前
情怀应助科研通管家采纳,获得10
27秒前
从来都不会放弃zr完成签到,获得积分10
31秒前
1459完成签到,获得积分10
33秒前
行者+完成签到,获得积分10
33秒前
GongSyi完成签到 ,获得积分10
34秒前
Boris完成签到 ,获得积分10
36秒前
哭泣笑柳完成签到,获得积分10
36秒前
万能图书馆应助大橙子采纳,获得10
39秒前
大眼睛土豆完成签到,获得积分10
43秒前
一条虫gg完成签到,获得积分10
46秒前
47秒前
48秒前
51秒前
大橙子发布了新的文献求助10
51秒前
dzy发布了新的文献求助10
55秒前
高分求助中
【提示信息,请勿应助】关于scihub 10000
Les Mantodea de Guyane: Insecta, Polyneoptera [The Mantids of French Guiana] 3000
徐淮辽南地区新元古代叠层石及生物地层 3000
The Mother of All Tableaux: Order, Equivalence, and Geometry in the Large-scale Structure of Optimality Theory 3000
Handbook of Industrial Diamonds.Vol2 1100
Global Eyelash Assessment scale (GEA) 1000
Picture Books with Same-sex Parented Families: Unintentional Censorship 550
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 4038157
求助须知:如何正确求助?哪些是违规求助? 3575869
关于积分的说明 11373842
捐赠科研通 3305650
什么是DOI,文献DOI怎么找? 1819255
邀请新用户注册赠送积分活动 892655
科研通“疑难数据库(出版商)”最低求助积分说明 815022