高温后无烟煤孔隙演化及多孔弹塑性变形特征研究  

Study on pore evolution and porous elastoplastic deformation characteristics of anthracite after high temperature

作　　者：周长冰 陈鑫[1] 张源 万志军[2,3] ZHOU Changbing;CHEN Xin;ZHANG Yuan;WAN Zhijun(School of Civil Engineering,Shaoxing University,Shaoxing 312000,China;School of Mines,China University of Mining and Technology,Xuzhou 221116,China;Key Laboratory of Deep Coal Resource Mining,Ministry of Education,Xuzhou 221116,China)

机构地区：[1]绍兴文理学院土木工程学院,浙江绍兴312000 [2]中国矿业大学矿业工程学院,江苏徐州221116 [3]深部煤炭资源开采教育部重点实验室,江苏徐州221116

出　　处：《中国矿业》2022年第8期165-172,共8页China Mining Magazine

基　　金：国家自然科学基金项目资助(编号:52074266;51504236)。

摘　　要：为研究热解后无烟煤孔隙发育特征及变形规律,本文对无烟煤进行常温下-500℃的热解处理,而后对尺寸为Φ50 mm×100 mm的试样开展单轴压缩实验,获得了应力-应变曲线,并结合压汞实验,分析了无烟煤的孔隙演化特征以及变形规律。研究结果表明:大孔的发育主导整个试样变形过程和孔隙演化过程,其阈值为300℃;中孔、大孔控制了无烟煤的破坏模式,300℃时由脆性破坏向韧性破坏转化;常规宏观弹性模量计算方法认为,煤体为完全弹性变形,而实验结果显示变形是弹性和塑性同时存在的,孔隙率越高,多孔塑性压缩变形量越大;本文定义了真弹性模量并给出了计算方法,分离出完全弹性变形与多孔塑性压缩变形;建立了多孔塑性变形的硬化模型,并通过数值计算进行了验证,吻合度较好。In order to study the pore development characteristics and deformation law of anthracite after pyrolysis,anthracite is pyrolyzed at room temperature-500℃,and then uniaxial compression tests are carried out onФ50 mm×100 mm samples and stress-strain curves are obtained.The characteristics of pore evolution and deformation of anthracite are analyzed by mercury injection experiment.The results show that the development of macropores dominates the whole process of deformation and pore evolution,and the threshold is 300℃.Medium and large pores control the destruction mode of anthracite,and the destruction mode changes from brittle failure to ductile failure at 300℃.The conventional macroscopic elastic modulus method considers that the coal body is completely elastic deformation,but the experimental results show that the deformation is both elastic and plastic.The higher the porosity is,the more porous plastic compression deformation is.The true elastic modulus is defined and the calculation method is given.The complete elastic deformation and the porous plastic compression deformation are separated.The hardening model of porous plastic deformation is established and verified by numerical calculation with good coincidence.

关 键 词：煤炭热解 弹性模量 孔隙演化 弹塑性变形 

分 类 号：TD849.4[矿业工程—煤矿开采]