初始应力状态及路径对含瓦斯软硬组合煤体失稳的影响

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中文摘要：考虑初始应力状态,以原生煤和构造煤形成的软硬组合煤体为研究对象,分析其在3种应变情况下的主应力变化,得到考虑初始应力状态的界面不协调变形及附加应力的表达式,结合摩尔-库伦强度准则评判了组合煤体的强度特征及破坏形式;依据煤体参数讨论3种不同应力路径对组合煤体失稳过程的影响;分析初始应力及应力变化对附加应力的影响并对组合煤体失稳的预防提出了相应建议.结果表明:2种煤体应变性质差异及界面黏聚力的存在,使得界面出现不协调变形及附加应力.附加应力改变了界面煤体的最小主应力,使组合煤体强度关系复杂,不同应变情况下的失稳形式多达7种.水平应力减小垂向应力增加的应力路径下组合煤体最容易出现破坏,该应力路径下组合煤体破坏时的应力集中系数为1.58,卸载掉的水平应力为2.06 MPa,显著低于水平应力不变垂向应力增加及水平应力减小垂向应力不变2种应力路径.垂向应力与水平应力引起的附加应力差异导致不同应力路径下组合煤体破坏形式出现变化,由界面原生煤首先破坏转变为远离界面构造煤首先破坏.初始应力状态与应力路径变化均通过影响组合煤体不协调变形与界面附加应力来影响界面煤体强度,进而影响组合煤体的失稳过程.

外文标题：Influence of initial stress state and stress path on the instability of combination formed by intact coal and tectonic coal containing gas

外文摘要：In this paper,the combination formed by intact coal and tectonic coal was regarded as research object.Considering the initial stress state,the principal stress changes of combina-tion under three strain conditions were analyzed,and the expressions of interface uncoordinated deformation and additional stress were obtained.Combined with the Mohr-Cou-lomb strength criterion,the strength characteristics and failure forms of combination were e-valuated.According to the parameters of coal,the influence of three different stress paths on the instability process of combination was discussed.The affect of initial stress state and stress change on additional stress was analyzed,and corresponding suggestions that prevent the in-stability of combination were made.The results show that due to the difference of strain in two coals and existence of interfacial cohesion,the interface uncoordinated deformation and addi-tional stress appear.The additional stress changes the minimum principal stress of the interface coal,which makes the strength relationship of the combination complex and instability forms up to 7 kinds under different strain conditions.Under the stress path of horizontal stress de-creases and vertical stress increases,the combination is most likely to be damaged.Under this stress path,while the combination is damaged,the stress concentration coefficient is 1.58 the unloaded horizontal stress is 2.06 MPa,which is significantly lower than the two stress paths of horizontal stress constant vertical stress increases and horizontal stress decreases and vertical stress constant.The difference of additional stress caused by vertical stress and horizontal stress leads to the change of instability form of combination under different stress paths,from the first failure of interface intact coal to the first failure of tectonic coal away from the inter-face.Both the initial stress state and the stress path affect the strength of the interface coal body by affecting the uncoordinated deformation and the additional stress,thus affecting the instability process of the combination.

外文关键词：

combination of coalstrength criterionstress pathmechanical instabilityinsta-bility control of coal

作者：

卢守青、刘永富、孙建中、贝太彪、秦玉金、张荣、宋权浩、张永亮、撒占友、刘杰

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作者单位：

青岛理工大学机械与汽车工程学院,山东青岛 266525

赛飞特工程技术集团有限公司,山东青岛 266061

中煤科工集团沈阳研究院有限公司煤矿安全技术国家重点实验室,辽宁抚顺 113122

中国民航大学安全科学与工程学院,天津 300300

西南石油大学理学院,四川成都 610500

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关键词：

组合煤体强度准则应力路径力学失稳煤体失稳防治

基金：

辽宁省自然科学基金项目山东省自然科学基金项目山东省自然科学基金项目国家自然科学基金项目国家自然科学基金项目

项目编号：

2022-KF-23-05ZR2023ME031ZR2023ME0125237420952304276

出版年：

2024

DOI：

10.13247/j.cnki.jcumt.20240003

中国矿业大学学报

中国矿业大学

中国矿业大学学报

CSTPCD北大核心

影响因子：1.83

ISSN：1000-1964

年,卷(期)：2024.53(4)

参考文献量17