煤炭地下气化覆岩相似材料热损伤特性研究  

Study on Thermal Damage Characteristics of Similar Overburden Materials in Underground Coal Gasification

作　　者：辛林[1,2] 韩立民 冯洺泽 李凯旋[1] 吴景 李佳泽 XIN Lin;HAN Linmin;FENG Mingze;LI Kaixuan;WU Jing;LI Jiaze(College of Safety and Environmental Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Key Laboratory of Ministry of Education for Mine Disaster Prevention and Control,Shandong University of Science and Technology,Qingdao,Shandong 266590,China)

机构地区：[1]山东科技大学安全与环境工程学院,山东青岛市266590 [2]山东科技大学矿山灾害预防控制-省部共建国家重点实验室培育基地,山东青岛市266590

出　　处：《矿业研究与开发》2021年第11期52-57,共6页Mining Research and Development

基　　金：山东省自然科学基金面上资助项目(ZR2020ME084);国家自然科学基金项目(51504142)。

摘　　要：为了开展煤炭地下气化三维相似模拟模型试验,对覆岩相似材料热损伤特性开展试验研究。对覆岩相似材料在不同温度下处理,并进行单轴压缩试验,研究分析其力学性能及热损伤特性随温度的变化规律。得出结论:加热后各试件的直径稍微增大,高度有增有减,质量和密度降低;高温处理后的试件其应力-应变曲线通常经历孔隙压实、弹性变形、断裂和破坏4个阶段;试件的抗压强度随温度的升高而降低,试件经过600℃处理后,粗砂岩相似试件的抗压强度从1.61 MPa降低到0.622 MPa,降低61.38%,弹性模量从0.29 GPa降至0.12 GPa,降低59.4%;细砂岩相似试件的抗压强度从1.34 MPa降低到0.65 MPa,降低51.57%,弹性模量从0.28 GPa降至0.12 GPa,降低56.7%;选择弹性模量来定义损伤变量,试件的热损伤演化在100℃处存在一个阈值,在这个阈值之前,试件颗粒的热膨胀作用只是用来填充试件本身存在的孔隙裂隙,只有当试件在温度作用下将其内部的孔隙裂隙完全闭合后,损伤才显露出来。In order to carry out the three-dimensional similar simulation model test of underground coal gasification,the thermal damage characteristics of similar overburden materials were studied.The mechanical properties and thermal damage characteristics of similar overburden materials treated at different temperatures were studied by uniaxial compression tests.The results are as follows.Firstly,after heating,the diameter of each specimen increases slightly,the height increases and decreases,and the mass and density decrease.Secondly,the stress-strain curves of the specimens after high-temperature treatment usually go through four stages,including pore compaction stage,elastic deformation stage,fracture stage and failure stage.Thirdly,the compressive strength of the specimens decreases with the increase of temperature.After the specimens are treated at 600℃,the compressive strength of similar specimens of coarse sandstone decreases from 1.61 MPa to 0.622 MPa by 61.38%,and the elastic modulus decreases from 0.29 GPa to 0.12 GPa by 59.4%.Fourthly,the compressive strength of similar fine sandstone specimens decreases from 1.34 MPa to 0.65 MPa by 51.57%,and the elastic modulus decreases from 0.28 GPa to 0.12 GPa by 56.7%.Finally,the elastic modulus is selected to define the damage variable,the thermal damage evolution of the specimen has a threshold at 100℃.Before this threshold,the thermal expansion of the specimen particles is only used to fill the pores and fissures existing in the specimen itself.Only when the pores and fissures in the specimen are completely closed under the action of temperature,the damage would be revealed.

关 键 词：相似材料 高温作用 力学特性 损伤演化 

分 类 号：TD84[矿业工程—煤矿开采]