煤岩单体及原生组合体变形损伤特性对比试验研究

研究煤岩组合体在不同应力条件下的变形损伤规律,对揭示矿山动力灾害机制具有重要 意义。 在单轴加载条件下,分析原生煤岩组合体、人工煤岩组合体及煤岩单体应力-应变规律,通 过采集加载过程中试样声发射行为信息,初步探究原生煤岩组合体损伤破坏规律。 对比分析发 现:① 煤岩组合体界面的差异对煤岩组合体力学性质、声发射特征具有较大影响;② 单轴加载条 件下4种试样抗压强度依次为:岩样>人工煤岩组合体试样>原生煤岩组合体试样>煤样;③ 组 合体受载变形和峰值强度受介质间界面条件、弹性模量及尺寸效应等多重因素影响;④ 原生煤 岩组合体在加载屈服破坏阶段内部裂隙发育贯通现象相对活跃,且早期损伤主要发生在原生煤 岩组合体界面或附近煤岩体。

Comparative experimental study on deformation and damage characteristics of single coal rock and primary coal-rock combination

Thestudyofthedeformationandfailurelawsintheloadingprocessofcoal-rockcombination samplesareveryimportanttorevealthedynamicmechanismofminedisaster.Inthisstudy,themechanicaldeformationcharacteristicsofprimarycoal-rockcombination,artificialcoal-rockcombination,single coalandsinglerockwereanalyzedandobtainedunderuniaxialloadingconditions.Meanwhile,thedamageandfailurelawsofprimarycoal-rockcombinationwerepreliminarilyexploredbycollectingtheacousticemission(AE)behaviorinformationofsamplesduringloadingprocess.Throughcomparativeanalysis,itisfoundthat:①Theinterfacedifferenceofcoal-rockcombinationhasgreatinfluenceonthe mechanicalandAEcharacteristicsofcoal-rockcombination;②Theorderofuniaxialpeakstrengthof foursamplesis:rock>artificialcoal-rockcombination>primarycoal-rockcombination>coal;③The loadingdeformationandpeakstrengthofthecombinationbodyareinfluencedbymanyfactors,suchas?interfaceconditions,elasticmodulusdifferenceofdifferentmediaandsizeeffectofmedia;④Underthe influenceofprimaryinterface,thefracturedevelopmentandpenetrationintheprimarycoal-rockcombinationisrelativelyactiveduringtheloadingyieldfailurestage,andtheearlydamagemainlyoccursin theprimarycoal-rockcombinationorthecoalandrockneartheinterfaceofcombination.