加卸载条件下煤岩变形特性与渗透特征的试验研究

以原煤为研究对象,利用自主研制的含瓦斯煤热流固耦合三轴伺服渗流试验系统,采用加轴压、卸围压的应力控制方式开展煤岩加卸载试验,分析加卸载条件下煤岩变形特性和渗透特征的演化规律。研究结果表明：①加卸载试验峰值强度明显低于常规三轴压缩试验峰值强度,在加卸载过程中,主应力差有一个明显增加趋势,卸载第2阶段速率越大,其曲线斜率也越大,但峰值强度越小,对应的径向应变ε3、体积应变εV增加速率也越快,而到峰值后破坏阶段,均呈下降趋势。②加卸载过程中,煤岩渗透率、应力差与应变关系可以分为3个阶段,初始压密和屈服阶段、屈服后阶段、破坏失稳阶段。试件达到峰值后瓦斯渗透率出现突然小幅度上升,持续一段时间后,渗透率出...

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Bibliographic Details
Published in煤炭学报 Vol. 37; no. 9; pp. 1493 - 1498
Main Author 许江 李波波 周婷 刘东 程立朝 曹偈
Format Journal Article
LanguageChinese
Published 2012
Subjects
全应力应变
加卸载
变形特性
渗透率
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Summary:以原煤为研究对象,利用自主研制的含瓦斯煤热流固耦合三轴伺服渗流试验系统,采用加轴压、卸围压的应力控制方式开展煤岩加卸载试验,分析加卸载条件下煤岩变形特性和渗透特征的演化规律。研究结果表明：①加卸载试验峰值强度明显低于常规三轴压缩试验峰值强度,在加卸载过程中,主应力差有一个明显增加趋势,卸载第2阶段速率越大,其曲线斜率也越大,但峰值强度越小,对应的径向应变ε3、体积应变εV增加速率也越快,而到峰值后破坏阶段,均呈下降趋势。②加卸载过程中,煤岩渗透率、应力差与应变关系可以分为3个阶段,初始压密和屈服阶段、屈服后阶段、破坏失稳阶段。试件达到峰值后瓦斯渗透率出现突然小幅度上升,持续一段时间后,渗透率出现急剧陡增趋势。③煤岩渗透率的变化与煤岩的变形损伤演化过程密切相关,渗透率随变形的增大均呈二次多项式函数递增。
Bibliography:XU Jing , LI Bo-bo, ZHOU Ting, LIU Dong, CHENG Li-chao, CAO Jie（ 1. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China ;2. State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam , Chongqing University , Chongqing 400044,China）
11-2190/TD
loading and unloading ; coal rock ; deformation characteristics ; full stress-strain ; permeability
Making raw coal as research objects, used domestic-developed triaxial servo-controlled seepage equipment for thermo-fluid-solid coupling of coal containing methane, with one pressure control mode of increasing the axial com- pression and unloading confining pressure to carry out coal and rock loading and unloading test, and analyzed the evo- lution of coal deformation properties and permeability characteristics under loading and unloading conditions. Results show that coal peak intensity under loading and unloading conditions is significantly lower than that under conventional triaxial c
ISSN:0253-9993