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ID:33690166
大小:4.22 MB
页数:54页
时间:2019-02-28
《采空老区地表变形及沉陷机理研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、采空老区地表变形及沉陷机理研究摘要随着土地资源日益紧缺,为了最大限度的利用采空区,确保采空区上部重要交通工程和居民小区的安全,提出相应的采空区地表变形和沉陷治理技术,开展采空老区地表变形及沉陷机理研究具有重要的社会经济意义。论文基于三维有限差分法,针对实际煤矿采空老区条件,构建了数值分析模型,进而数值探讨了采空老区的地表变形基本特征及规律,以揭示采空老区上的地表变形规律和沉陷机理。数值模拟研究得出以下初步结论:1)在每层煤层被开挖后,上覆岩土层倾向上部区域出现水平应力较小,倾向下部则较大现象,随着开挖的继续,应力偏差逐
2、渐变小。2)地表沉降和变形曲率变化沿走向方向较小,而沿倾向变化较大;下沉基本以最大沉降点为中心对称分布。3)煤层开采后上覆岩体破坏主要沿走向方向发展,其中1捍层煤开采后上覆岩体垮落破坏,而其他煤层开采后上覆岩体则多发生断裂现象。4)地表沉降数值模拟结果与概率积分法、地表多年的矿区沉降实测值基本吻合。研究结论将有助于采空老区地表沉降控制,为老采空区地基处理技术提供了理论依据。关键词:采空区;沉陷机理;岩层移动;数值模拟;FLAC3D;概率积分法GroundDeformationandSubsidenceMechanism
3、ofOldMiningAreaABSTRACTWiththedecreaseoflandresources,tomakethemostoftheoldminingareas,andensurethesafetyofimportanttrafficengineeringandresidentialbuildingsfoundontheminingareas,theresearchofsubsidencemechanismandsurfacedeformationofminingareasisofimportantsoci
4、aleconomlcsignificanceIordevelopingasuitableandrationaltreatmenttechnology·Basedonthree.dimensionalfinitedifferencemethod,thenumericalmodellSdiscussedaccordingtotheactualconditionsofoldminingareas.Thedeformationfeaturesandlawofgroundsurfacewerefurtherinvestigate
5、dtorevealsubsidencemechanismofminingareas.Thepreliminaryconclusionsaredrawnasthefollowing:1、)Whenthecoalseamwasexcavatedonebyone,thesmallerstresswasobservedintheupperstrataareaalongthedipdirection,butthelargervalueinthebottomarea.Andthestressdeviationdecreasedwi
6、ththeexcavationprocess·21Thegroundsubsidenceandcurvaturechangedslightlyalongthestratastrike,ontheotherhand,changedgreatlyalongthedipdirection.Thesubsidencedistributedsymmetricallyaroundthecenterofthemaxsettlementascenter.3)Damageofoverlyingrockmassmainlyoccurred
7、atthedirectionofstrike-TheoverlayingrockmasseswerecollapsedaftertheCoal1wasmined,buttheoverlayingrockmasseswererupturedwhentheothercoalwasmined.41Thecomputedgroundsubsidencefromthenumericalsimulationwascoincidentwiththatfromtheprobabilityintegrationmethodandthem
8、easuredvalueofsurfacesubsidenceoveryears.Theseresultswillcontributetothesurfacesubsidencecontrol,andprovideatheoreticalbasisforthefoundationtreatmenttechniquesofoldmi
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