摘要
为探讨煤的构造变形机理，笔者选择三种不同煤级的煤样，在Ｔ＝３５０～７００℃，Ｐｃ＝４００～６００ＭＰａ，ε＝１０％～３０％，ε＝３．６３ｘ１０－６～２．５９ｘ１０－５Ｓ－１条件下进行高温高压变形实验。实验样品的应力－应变曲线以及变形构造（尤其是显微构造）特征表明：（１）煤的塑性变形程度随着煤级的增高而降低并逐渐消失；（２）气体的存在导致煤强度的明显下降，并对煤力学性质产生十分重要的影响；（３）大量气体的存在不仅促使煤强度的急剧下降，而且还能引起煤的强烈碎裂细化，从而有利于流变的发生。据此，笔者认为：（１）煤构造变形的韧性机制主要发生在煤级较低阶段，而在煤级较高阶段则以脆性机制为主导；（２）促使煤层强烈构造变形与流变的关键因素是煤中大量气体的存在。
To study mechanism of tectonic deformation of coal, the authors tested three kinds of sample of different ranks under conditions of T= 300～700℃,Pc= 400～600MPa,ε=10%～30% and ε=3.63x10-6～2.59x10-5S-1. The characteristics of stress-strain curves and deformation structures, especially micro structure of samples indicate that: (1) plastic deformation of coal gradually decreases with the increase of coal rank and disappears gradually; (2) The presence of gas causes obvious decrease in coal strength and has a very important effect on the mechanical properties of coal; (3)A great quantity of gas in coal can not only decrease coal strength but also can pulverize the coal, thus affects rheology of coal. The authors consider that (1) the ductile mechanism of tectonic deformation of coal dominate at the initial stage of metamorphism, and the brittle mechanism in the later stage of metamorphism; (2) the important factor leading to drastic tectonic deformation and flow of coal bed is gas in coal.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
1994年第3期324-332,共9页
Journal of China Coal Society
关键词
煤
高温高压实验
构造变形
coal, high temperature and high pressure test, tectonic deformation, rheology of coal seam, microstructure
