摘要
为获取循环荷载作用下不同高度煤样渗透率的变化规律,应用煤岩三轴加载渗流试验装置,对直径相同高度不同的煤样进行循环加卸载轴压渗透性试验。研究结果表明:加载阶段,渗透率随轴压增加而降低;卸载阶段,渗透率随轴压降低而增加;渗透率与轴压呈负指数函数关系,渗透率应力敏感性随循环次数增加而降低;加载阶段与卸载阶段渗透率产生明显差值,其差值随循环次数增加而降低,渗透率损失量主要发生在初期加卸载阶段。不同高度煤样应力敏感性存在显著差异,应力敏感性随煤样高径比增加而降低;在加载与卸载阶段,无因次渗透率损失量随高径比增加而增大;经历循环加卸载作用后,渗透率损失率随高径比增加而增大,渗透率恢复率随高径比增加而降低。
In order to obtain the permeability variations of coal samples with different heights under cyclic loading,triaxial loading seepage experiment device was used to carry out the cyclic axial loading and unloading compression tests on coal samples with the same diameter and different heights. The results show that the permeability decreases with the increasing of the axial compression in the loading stage. The permeability increases with the decreasing of the axial compression in the unloading stage. The relationship between the permeability and the axial compression is a negative exponential function and the stress sensitivity of permeability decreases with the increasing of cycle numbers. The permeability has a significant difference during the loading and unloading stage and the permeability difference decreases with the increasing of cycle numbers. The permeability reduction mainly occurs in the initial stage of loading and unloading. There are significant differences in stress sensitivity for coal samples with different heights. The stress sensitivity decreases with the increasing of the height to diameter ratios of coal samples. During the loading and unloading stage,the reduction of dimensionless permeability increases with the increasing of the height to diameter ratio. After cyclic loading and unloading,the reduction rate of permeability increases with the increasing of height to diameter ratio. The recovery rate of permeability decreases with the increasing of height to diameter ratio.
作者
王辰霖
张小东
李贵中
杜志刚
张硕
WANG Chenlin;ZHANG Xiaodong;LI Guizhong;DU Zhigang;ZHANG Shuo(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454000,China;Collaborative Innovation Center of Coalbed Methane（Shale Gas）in Central Plains Economics Zone,Jiaozuo,Henan 454000,China;Langfang Branch,PetroChina Exploration and Development Research Institute,Langfang,Hebei 065007,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第10期2299-2308,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41372162)
河南省高校科技创新团队支持计划(14IRTSTHN002)~~
关键词
岩石力学
循环加卸载
轴压
高度
渗透率
应力敏感性
rock mechanics
cyclic loading and unloading
axial compression
height
permeability
stress sensitivity
