电法在堤坝深埋长隧道突水灾害等工程勘察中的应用PPT课件

1、1.高密度电阻率成像(Resistivity Tomography, RT) Depth: 0200 m第1页/共28页Fig.1 The arrangement of electrodes for a 2-D electrical survey and the sequence of measurements used to build up a pseudo-sectionElectrode NumberC1P2P1C2Station 1ResistivityMeterLaptopComputerC1P1P2C22a2a2aStation 181220345678910 11 12 13

2、141918171615aaa. . . . . . . . . . . . . . . . .11832435156DataLeveln=1n=2 n=3 n=4 n=5 n=6C1P1P2C23a3a3aStation 32第2页/共28页RT with Zhody method Fig.2 Single high resistivity body(a) Model; (b) RT result10( , )( , )( , )( , )iicil nl nl nl nZhody method is one kind of iteration inversion procedure, Th

3、e iteration equation is:510152025-10-550200201(a)点 距 （ 米 ）深 度 （ 米 ）510152025-10-530120150200250(b)点 距 （ 米 ）深 度 （ 米 ）Distance/mDistance/mDepth/mDepth/m/m/m第3页/共28页(b)102030405060708090100Horizontal Distance (m)70605040302010Depth (m)-0.050.000.050.100.150.200.250.300.350.400.450.50(a)1020304050607080

4、90100Horizontal Distance (m)70605040302010Depth (m)-0.050.000.050.100.150.200.250.300.350.400.450.50Fig.3 The fault model and RT sections(a) Model; (b) RT section. The inversion result has a very good match to the model.RT with Integral method13310()42jjjjkjjjkjjjUUUAUUrAA U The sensitive equation o

5、f potential changing with media resistivity is:The inversion equation is:第4页/共28页45Result in Da-ye of Shan Dong of ChinaThe purpose for dam RT exploration is to find the water leaking position第5页/共28页135014001450150015501600(c)135014001450150015501600135014001450150015501600(d)1350140014501500155016

6、00100150200250300350400450500550600(a)100150200250300350400450500550600100150200250300350400450500550600(b)1001502002503003504004505005506000100200300350400500550600700800900110012001300170150130170150130168148128168148128ABCCCCAAABBCCBBB海拔（m）海拔（m）海拔（m）桩号（距离：m）桩号（距离：m）桩号（距离：m）山东沂水跋山水库大坝电阻率 CT 解释剖面(a

7、)西段，海拔约 180m (b)西段，海拔约 178m(c)东段，海拔约 180m (d)东段，海拔约 178m桩号（距离：m）A-坝体 B-弱风化带 C-基岩Station/mSea level /mSea level /mSea level /mStation/m Station/m/mA: Dam body, B: weathered layer, C: base rockFig.6 Four resistivity imaging sections for Ba-shan dam Figure (a) and (b) are the two parallel profiles with

8、 the space 20m at the same position of the dam; Figure (c) and (d) are the other two parallel profiles with the space 20m at another position of the dam.The position of the ancient riverBa-shan Dam第6页/共28页2. CSAMT 数据反演及工程勘察(Control Source Audio-Frequency Magnetotelluric, CSAMT) Depth: 01500m第7页/共28页

9、Frequency: 0.25Hz10kHz Depth: 0 1500mPower: 30kw 2.1 CSAMT working configuration and parametersABRTxRxNMFig.8 CSAMT 工作示意图 第8页/共28页 2.2 Some CSAMT research workCSAMT勘察中突出的问题是： 近场问题 静态问题 地形问题第9页/共28页The whole frequency domain resistivity correctionK 3 layers media1212100,500, 3100100 ,500 ,2000 ,17.5m

10、mmhm hm rm Before correctionAfter correctionMT CurveHK 4 layers media23400 ,500 ,2000 ,17.5hm hm rm 12100,2,mm 341100,2,100mm hm Near field correctionMT CurveBefore correctionAfter correctionFig.9 CSAMT近场校正第10页/共28页 Filter method EMAP method Curves shift method 2.5D FEM inversion02004006008001000-14

11、00-1200-1000-800-600-400-200002040608010012014016018020022024026028030032034036038040042044046048002004006008001000-1400-1200-1000-800-600-400-200002040608010012014016018020022024026028030032034036038040042044046048002004006008001000-1400-1200-1000-800-600-400-200002040608010012014016018020022024026

12、0280300320340360380400420440460480(a)(b)(c)(d)(e)静态引起的条带异常02004006008001000-1400-1200-1000-800-600-400-2000020406080100120140160180200220240260280300320340360380400420440460480Static correctionConclude：The correction effect with curve shift method and 2.5D FEM is better.1D inversion before correctio

13、n 1D inversion after EMAP correction1D inversion with curve shift correction, frequency 256-1024 Hz1D inversion with curve shift correction, frequency 32-128 Hz2.5D FEM inversionFig.10 CSAMT 静态校正 第11页/共28页Developed 1D strip-layer method, 2D RRI and 2.5D FEM inversion methods60657075808590-60-55-50-4

14、5-40-35-303050709011060657075808590-60-55-50-45-40-35-301001010 m m m( m)2D inversion profileTwo conductivity bodies model2.5D inversion profileTwo conductivity bodies covered by 2 thin layersData inversionFig.11 CSAMT 反演 第12页/共28页 2.3 CSAMT工程勘察实例 深埋长隧道 矿突水灾害勘察 地质构造勘察第13页/共28页CSAMT 南水北调隧道勘察12第14页/共2

15、8页图13 南水北调西线一期工程阿克河以东20km工程质剖面：西剖面东剖面第15页/共28页图14 CSAMT 反演及推断解释剖面：第16页/共28页 低阻异常区目的是发现可能造成隧道施工隐患的断层、破碎带及含水异常带。 钻孔04-ZD-1018处的岩芯图片。岩性为泥质充填物和角砾混合物CSAMT 太行山隧道勘察Fig.15 CSAMT太行山隧道 第17页/共28页-1000100200300500600700800900100011001200tunnel positionSN100140180220260300340380420460500540Danger areaFig.16 CSAM

16、T resistivity inversion profile for DK88+880m第18页/共28页-200 -100010020030040050060050060070080090010001100120013005006007008009001000110012001300tunnel positionSN100140180220260300340380420460500540Danger areaFig.17 CSAMT resistivity inversion profile for DK88+750m第19页/共28页CSAMT牡丹江隧道勘察图18 第20页/共28页CS

17、AMT法煤田突水隐患勘察201001802603404205005806607408209009801060 1140 1220 1300 1380 1460 1540 1620 1700Station /m201001802603404205005806607408209009801060 1140 1220 1300 1380 1460 1540 1620 1700Fig.11 Resistivity Profile for Tang Shan Line D023 with CSAMT-1500-1400-1300-1200-1100-1000-900-800-700-600-500-40

18、0-300-200-1000Depth /m-1500-1400-1300-1200-1100-1000-900-800-700-600-500-400-300-200-1000-20001030506080100150200300400500700900120015001510152025303540444379983.043(X)470160.953(Y)4381626.602(X)470668.973(Y)Stake /NO.Station /mF20Q-Quartery 5-coal layer 5 12-12 coal layer 12 14-14 coal layer 14Q512

19、14O2/mDF43F19在煤系地层中有一断层F，一直延深到灰岩基底。电阻率约为10m，与周围岩石或煤系地层相比，电阻率差异较大，判断该断层含水，在布置采区巷道时给予了充分的考虑。第21页/共28页 图20 为河北某煤矿5煤底板深度反演电阻率平面图。异常的范围在该图上得到明显反应。第22页/共28页525456585 105 125 145 165 185 205 225 245 265x / m-325-305-285-265-245-225-205-185-165-145-125-105-85-65-45-25-51535557595115135155175Ds / mQFeF1F2O2-

20、200010203040507090130160200300366m/CaveCaveRichly water Water bearing areabearing areaFracturewaterFig.21 CSAMT inversion profile for line 3CSAMT 铁矿顶板含水性预测第23页/共28页-80-60-40-20020406080100120140160180200220240260 x / m-100102030405060708091011-10010203040506070809111015101520253020553900205540002055

21、41002055420020554300400850040084004008300400860040080004008000400810040082004008300400850040086002055390020554000205541002055420020554300FeO2O2O2EF1F2CaveCaveCaveCaveCaveRichly waterbearing areaCaveRichly water CaveCavewater bearingFig.22 CSAMT inversion slice for depth 25m in iron mine第24页/共28页-80-

22、60-40-20020406080100120140160180200220240260 x / mRichly water-100102030405060708091011-1001020304050607080911101510152025302055390020554000205541002055420020554300400850040084004008300400860040080004008000400810040082004008300400850040086002055390020554000205541002055420020554300F1F2O2O2O2FeECaveCaveCaveCaveCaveCavebearing areaRichl