瓦斯压力对非均质煤岩抗压强度尺寸效应的影响  

Influence of gas pressure on compressive strength size effect of inhomogenous coal

作　　者：赵瑜[1,2] 李晓红[2] 卢义玉[2] 康勇[2] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学西南资源开发及环境灾害控制工程教育部重点实验室,重庆400044

出　　处：《煤炭学报》2009年第8期1081-1085,共5页Journal of China Coal Society

基　　金：国家自然科学基金创新群体基金资助项目(50621403);国家自然科学基金资助项目(50804060);西部交通建设科技资助项目(200731800037)

摘　　要：通过非均质固、气耦合数值试验的方法,研究不同瓦斯压力作用下非均质煤岩抗压强度尺寸效应的影响规律及其作用机理.研究表明:含瓦斯煤岩的抗压强度随着瓦斯压力的增加而呈非线性降低,其降低的幅度随着瓦斯压力的增加而增大;在煤岩裂纹萌生、扩展、演化过程中,通过渗流场与应力场的耦合作用,瓦斯压力降低了煤岩的有效应力,促使裂纹不同方向发育,导致应力局部集中和变形的局部化;增加煤岩的非均质性,促使煤岩均质度动态演化,使得同一均质度煤岩,瓦斯压力越大,抗压强度尺寸效应越明显,瓦斯压力对非均质煤岩抗压强度尺寸效应有显著影响.Based on the solid and gas coupling numerical tests of inhomogeneity, the relationship between the gas pressure and compressive strength size effect of inhomogenous coal was investigated. The results show that the compressive strength of coal has a trend to reduce nonlinearly as the gas pressure increases, and the higher the gas pressure, the larger the range of decrease is. The microfractures in coal appears and grows under coupling of seepage field and stress field, which make the materials tend to be inhomogenous, and the inhomogeneity develops with the gas pressure increase, the compressive strength size effect under gas pressure is remarkable. At the same inhomogeneity, the higher the gas pressure, the more obvious the compressive strength size effect becomes, the gas pressure can increase the sensitivity of the size of coal to their compressive strength.

关 键 词：瓦斯压力 非均质性 抗压强度 尺寸效应 

分 类 号：TU458[建筑科学—岩土工程]