不同稳定时间对煤的变形及渗透特性影响试验研究  

EXPERIMENTAL RESEARCH ON DEFORMATION AND PERMEABILITY CHARACTERISTICS OF COAL AT DIFFERENT STABILITY TIMES

作　　者：许江[1,2] 张敏[1,2] 李波波[1,2] 杜伟[3] 周婷[1,2] 曹偈[1,2] 

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室,重庆400044 [3]重庆市北碚区国土资源管理分局,重庆400700

出　　处：《岩石力学与工程学报》2014年第7期1388-1397,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：重庆市基础与前沿研究计划项目(cstc2013jjB90001);国家重点基础研究发展计划(973)项目(2011CB201203);"十二五"国家科技重大专项资助项目(2011ZX05034–004)

摘　　要：为探讨在采动应力反复扰动下煤的变形及渗透特性,利用自主研发的含瓦斯煤岩热流固耦合三轴伺服渗流装置,进行不同稳定时间条件下煤的循环荷载试验。研究结果表明:(1)不同稳定时间条件下煤的循环加卸载应力–应变曲线不相重合,形成塑性滞回环;随着稳定时间的增加,渗透率有相同的变化趋势,初始渗透率下降幅度亦减小。渗透率与轴向应变随主应力差增加呈负相关变化,轴向应变增大渗透率减小,反之亦然。(2)煤的轴向应变最大值随稳定时间增加先减小后增大,并在稳定时间为100 s时到达最小;渗透率最小值随稳定时间增加先增大后减小,并在稳定时间为100 s时到达最大。煤的渗透率变化与轴向变形的发展密切相关。(3)不同稳定时间条件下煤的渗透率变化均滞后于体积应变变化,且随稳定时间的增加,滞后量有增大的趋势。To study the characteristics of deformation and permeability of coals under repeated disturbance of stresses, cyclic loading tests with different time lengths of stabilization were carried out using a servo-controlled triaxial seepage device which was developed in house. The loading and unloading stress-strain curves with different time lengths of stabilization form plastic hysteresis loops. As the time lengths of stabilization increased, the initial permeability reduced slowly but the trends of variation of the permeability remained the same. The permeability decreased with the increasing of the principal stress. The maximum axial strain of coal decreased initially and then increased as the time lengths of stabilization increased and it reached the minimum value at the time lengths of stabilization of 100 s. The minimum permeability of coal increased initially and then decreased and it reached the maximum value at the time lengths of stabilization of 100 s. The permeabilities of coals are closely related to the development of axial deformation. The variations of permeability were always lagged behind that of the volumetric strains. The lagged time lengths increased with the increasing of the time lengths of stabilization.

关 键 词：岩石力学 循环荷载 稳定时间 渗透率 滞后性 

分 类 号：TU45[建筑科学—岩土工程]