電法在堤壩、深埋長隧道、突水災(zāi)害等工程勘察中的應(yīng)用(底青云).ppt

1、電法在堤壩、深埋長隧道、突水災(zāi)害等工程勘察中的應(yīng)用,底青云、王若、王光杰等 中國科學(xué)院地質(zhì)與地球物理研究所 2008年11月1日,報告內(nèi)容： - 高密度電阻率成像系統(tǒng)（RT) - CSAMT 反演和勘察應(yīng)用,高密度電阻率成像(Resistivity Tomography, RT),Depth: 0200 m,Fig.1 The arrangement of electrodes for a 2-D electrical survey and the sequence of measurements used to build up a pseudo-section,RT with Zhody

2、method,Fig.2 Single high resistivity body (a) Model; (b) RT result,Zhody method is one kind of iteration inversion procedure, The iteration equation is:,Fig.3 The fault model and RT sections Model; (b) RT section. The inversion result has a very good match to the model.,RT with Integral method,The s

3、ensitive equation of potential changing with media resistivity is:,The inversion equation is:,Result in Da-ye of Shan Dong of China,The purpose for dam RT exploration is to find the water leaking position,Fig.6 Four resistivity imaging sections for Ba-shan dam Figure (a) and (b) are the two parallel

4、 profiles with 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 river,Ba-shan Dam,2. CSAMT 數(shù)據(jù)反演及工程勘察(Control Source Audio-Frequency Magnetotelluric, CSAMT),Depth: 01500

5、m,Frequency: 0.25Hz10kHz Depth: 0 1500m Power: 30kw,2.1 CSAMT working configuration and parameters,Fig.8 CSAMT 工作示意圖,2.2 Some CSAMT research work,CSAMT勘察中突出的問題是： 近場問題 靜態(tài)問題 地形問題,The whole frequency domain resistivity correction,K 3 layers media,HK 4 layers media,Near field correction,Fig.9 CSAMT近場校正,

6、Filter method EMAP method Curves shift method 2.5D FEM inversion,Static correction,Conclude： The correction effect with curve shift method and 2.5D FEM is better.,1D inversion before correction,1D inversion after EMAP correction,1D inversion with curve shift correction, frequency 256-1024 Hz,1D inve

7、rsion with curve shift correction, frequency 32-128 Hz,2.5D FEM inversion,Fig.10 CSAMT 靜態(tài)校正,Developed 1D strip-layer method, 2D RRI and 2.5D FEM inversion methods,2D inversion profile,Two conductivity bodies model,2.5D inversion profile,Two conductivity bodies covered by 2 thin layers,Data inversion

8、,Fig.11 CSAMT 反演,2.3 CSAMT工程勘察實例,深埋長隧道 礦突水災(zāi)害勘察 地質(zhì)構(gòu)造勘察,CSAMT 南水北調(diào)隧道勘察,12,圖13 南水北調(diào)西線一期工程阿克河以東20km工程質(zhì)剖面：,西剖面,東剖面,圖14 CSAMT 反演及推斷解釋剖面：,低阻異常區(qū),目的是發(fā)現(xiàn)可能造成隧道施工隱患的斷層、破碎帶及含水異常帶。 鉆孔04-ZD-1018處的巖芯圖片。巖性為泥質(zhì)充填物和角礫混合物,CSAMT 太行山隧道勘察,Fig.15 CSAMT太行山隧道,Danger area,Fig.16 CSAMT resistivity inversion profile for DK88+880

9、m,Danger area,Fig.17 CSAMT resistivity inversion profile for DK88+750m,CSAMT牡丹江隧道勘察,圖18,CSAMT法煤田突水隱患勘察,19,在煤系地層中有一斷層F，一直延深到灰?guī)r基底。電阻率約為10m，與周圍巖石或煤系地層相比，電阻率差異較大，判斷該斷層含水，在布置采區(qū)巷道時給予了充分的考慮。,圖20 為河北某煤礦5煤底板深度反演電阻率平面圖。異常的范圍在該圖上得到明顯反應(yīng)。,Fig.21 CSAMT inversion profile for line 3,CSAMT 鐵礦頂板含水性預(yù)測,Fig.22 CSAMT inversion slice for depth 25m in iron mine,Fig.23 CSAMT inversion slice for depth 40m in iron mine,Geology structure exploration,Fig.24 Inverted resistivity profile with CSAMT for geology structure in Nan-yuan of Beijing city,Geology fault of Nan-yuan to Tong-xian,Quatern