基于时移高密度电法的覆岩精细探测方法研究
Fine detection of overburden strata based on time lapse high density resistivity method
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摘要: 地下煤层开采引起上覆岩层变形破坏,对变形破坏范围进行精细探测,可以为煤矿安全 高效绿色开采提供技术保障。 本论文分析了基于时移高密度电法的覆岩精细探测原理,建立了 采前和采后三维地质地球物理模型并进行了数值仿真计算。 结果表明:覆岩变形破坏在电阻率 变化率断面图中呈沙漏形异常,孔口位置约为裂隙带和弯曲下沉带的分界线,裂隙区相对压实 区为电阻率变化率高正异常区。 同时,进行了现场试验,发现电阻率变化率断面图中浅部异常 主要受沉陷裂隙和降水影响,沉陷裂隙形成电阻率变化率正异常,降水形成电阻率变化率负异 常;结合沙漏形异常形态和关键层层位,确定了裂隙带发育高度为98m,探测结果得到了钻探 结果验证。Abstract: Finedetectionforthedeformationfailureofoverburdenstratacausedbyundergroundmining mayprovidereliableguidanceforsafety,highefficientandgreencoalmining*Firstly,theprincipleofo⁃ verburdendetectionbasedontimelapsehighdensityresistivitymethodwasinvestigated*Then3Dgeo⁃ logic⁃geophysicalmodelsofoverburdenstratabeforeandafterminingwereconstructed,andthecorre⁃ sponding numerical simulation was carried out by using these models*It is demonstrated that deformationfailureofoverburdenstrataishourglass⁃likeintheresistivitychangerateprofileandorifice istheseparatrixbetweenthefracturedzoneandthebendingzone*Furthermore,fieldtestswerecarried out,resultsshowthatthesurfacesubsidencecausedpositiveanomalyandprecipitationcausednegative anomalyintheresistivitychangerateprofile*Basedonthehourglass⁃likeanomalymorphologyandkeystratumlayer,theheightoffracturedzonewasdeterminedtobe98m*Finally,theresultsfromtime lapsedetectionwereverifiedbydrillingresults*