岩土力学2018，Vol.39Issue(4)：1346-1354,9.DOI:10.16285/j.rsm.2016.1140
分级加-卸载条件下原煤的渗透及能耗特征研究
Experimental research on energy dissipation and seepage properties of coal under loading-unloading conditions at different stress levels
摘要
Abstract
In this paper,loading-unloading experiments were carried out on gas-contained coal under different stress levels by using self-made thermal-hydro-mechanical (THM) coupling equipment.The characteristics of the deformation,seepage and energy dissipation of coal and rock were analysed,and the damage variable equation was also established by considering the energy dissipation.Research results show that the cumulative residual deformation increases gradually with the advancing of cyclic loading-unloading.The relative residual deformation decreases firstly,then maintains stable at a certain value,and finally rises again when the coal sample is nearly destroyed.With the advancing of cyclic loading-unloading,the overall trend of permeability decreases spirally,and thcn increases until the coal sample is fractured.Moreover,a sharp increase is observed at the moment of destruction.The absolute recovery rate of permeability and relative recovery rate of permeability are defined as ηj and ηx to quantitatively analyse the changes of permeability in loading and unloading processes,respectively It is found that ηj decreases firstly,and then increases at the critical moment of destruction.However,ηx increases steadily during the process,where ηx maintains at 85％-95％ in the elastic stage,and ηx is more than 100％ at the critical moment of destruction.With the advancing of cyclic loading-unloading,the cumulative dissipated energy grows exponentially,and the single-stage cycle of dissipation energy increases.With the increase of the axial stress,the principal stress difference increases,and the value of damage variable also increases.In addition,damage variable of coal Dc is 0.9 when coal is fractured.关键词
含瓦斯煤/分级加-卸载/残余变形/渗透率/耗散能Key words
coal containing gas/different level loading-unloading/residual deformation/seepage/energy dissipation分类
矿业与冶金引用本文复制引用
段敏克,蒋长宝,俞欢,陆天宇,钮彬炜,孙东玲..分级加-卸载条件下原煤的渗透及能耗特征研究[J].岩土力学,2018,39(4):1346-1354,9.基金项目
国家自然科学基金资助项目(No.51674048) （No.51674048）
重庆市科技计划资助项目(No.cstc2015jcyjA90009,No.cstc2015jcyjBX0076).This work was supported by the National Natural Science Foundation of China(51674048) and the Fundamental and Advanced Research Projects of Chongqing(cstc2015jcyjA90009,cstc2015jcyjBX0076). （No.cstc2015jcyjA90009,No.cstc2015jcyjBX0076）
