【摘要】：激電測(cè)深是在穩(wěn)定的直流電場(chǎng)或者交流電場(chǎng)下,通過逐漸增加供電電極之間的距離來進(jìn)行地下電性性質(zhì)的觀測(cè)工作。使用對(duì)稱四級(jí)裝置可以得到同一觀測(cè)點(diǎn)下方不同深度范圍內(nèi)的視電阻率以及視極化率。根據(jù)地表各點(diǎn)不同供電極距時(shí)測(cè)量的視電阻率和視極化率的變化特點(diǎn)來對(duì)地下礦產(chǎn)資源進(jìn)行勘察,確定其分布范圍并解決相應(yīng)的地質(zhì)問題。地形對(duì)激電測(cè)深中的視電阻率影響較大,因此在實(shí)際應(yīng)用中,起伏地形下所獲得的視電阻率數(shù)據(jù)需要進(jìn)行地形改正,壓制地形所引起的視電阻率假異常。激電測(cè)深使用對(duì)稱四級(jí)觀測(cè)裝置,為了校正該裝置下的地形對(duì)視電阻率的影響,本文使用求解維度小,計(jì)算效率更高的邊界單元法分別正演原始地形與起伏地形下均勻介質(zhì)的視電阻率,使用比較法對(duì)各個(gè)測(cè)深點(diǎn)獲得的實(shí)測(cè)數(shù)據(jù)進(jìn)行數(shù)值校正,并且使用正交投影法來還原各供電極距下測(cè)深范圍的真實(shí)位置,通過兩種方法聯(lián)合的方式壓制起伏地形對(duì)視電阻率的影響。該地形改正方法具有計(jì)算速度快、適用性高、穩(wěn)定的特點(diǎn)。為了檢驗(yàn)該地形改正的效果,文中分別建立了若干二維非均勻介質(zhì)不同地形下的模型體,對(duì)模型體使用邊界單元法正演出對(duì)稱四級(jí)觀測(cè)裝置下的視電阻率值,并使用聯(lián)合地形改正分別對(duì)地表各點(diǎn)視電阻率值以及有效測(cè)深范圍的位置進(jìn)行改正,有效壓制了地形所造成的假異常,突出了地下異常體所引起的異常。最后將該聯(lián)合地形改正的方法應(yīng)用于湘西的銅鎳礦區(qū),含銅鎳礦的巖體會(huì)產(chǎn)生高重力、高磁化率、低視電阻率、高視極化率異常。對(duì)礦區(qū)采集的大功率激電數(shù)據(jù)中的視電阻率進(jìn)行地形改正。非均勻極化介質(zhì)在地表觀測(cè)到的視極化率受地形的影響其幅值與形態(tài)會(huì)發(fā)生變化,但是變化幅度較小,一般不會(huì)出現(xiàn)假視極化率異常。在該銅鎳礦區(qū)中,將地形改正后所獲得的視電阻率與視極化率圖件進(jìn)行對(duì)比,在礦區(qū)的1號(hào)巖體區(qū)域出現(xiàn)吻合度較高的低視電阻率與高視極化率對(duì)應(yīng)關(guān)系,且與高重力、高磁異常、地質(zhì)資料對(duì)應(yīng)較好,為礦區(qū)的井位設(shè)計(jì)提供有力支撐。
[Abstract]:IP sounding is to observe the underground electrical properties by gradually increasing the distance between the power supply electrodes in a stable DC or AC electric field. The apparent resistivity and apparent polarizability at different depths below the same observation point can be obtained by using a symmetrical four-stage device. According to the change characteristics of apparent resistivity and apparent polarizability measured at different power supply poles at different points on the surface, the underground mineral resources are investigated, the distribution range is determined and the corresponding geological problems are solved. Terrain has a great influence on apparent resistivity in IP sounding, so in practical application, the apparent resistivity data obtained under undulating terrain need to be corrected to suppress the false anomaly of apparent resistivity caused by terrain. In order to correct the effect of topography on apparent resistivity of IP sounding, a symmetrical four-order observation device is used in this paper, and the solution dimension is small. The more efficient boundary element method is used to calculate the apparent resistivity of the homogeneous medium in the original terrain and the undulating terrain respectively, and the measured data obtained from each bathymetric point are numerically corrected by the comparison method. The orthogonal projection method is used to restore the true position of the sounding range under each distance of the power supply pole, and the effect of the undulating topography on the apparent resistivity is suppressed by the combination of the two methods. The terrain correction method has the characteristics of fast computing speed, high applicability and stability. In order to test the effect of terrain correction, several models of two-dimensional non-uniform medium under different terrain are established, and the apparent resistivity values under symmetrical four-order observation device are obtained by using boundary element method for the model body. Combined terrain correction is used to correct the apparent resistivity and the position of the effective sounding range, which effectively suppress the false anomaly caused by the terrain and highlight the anomaly caused by the underground anomaly body. Finally, the combined terrain correction method is applied to the Cu-Ni ore area in the west of Hunan Province. The rock mass containing Cu-Ni ore will produce the anomalies of high gravity, high magnetic susceptibility, low apparent resistivity and high apparent polarizability. The terrain correction of apparent resistivity in high power IP data collected from mining area is carried out. The apparent polarizability observed by the non-uniform polarization medium on the surface of the earth is affected by the topography, its amplitude and shape will change, but the range of change is relatively small, generally there will be no false apparent polarizability anomaly. In this copper-nickel mine, the apparent resistivity obtained after terrain correction is compared with the apparent polarizability map. In the area of rock mass No. 1 in the mining area, there is a high correspondence between low apparent resistivity and high apparent polarizability, and it is also related to high gravity. The high magnetic anomaly and the geological data correspond well, which provide strong support for the well position design of the mining area.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P631.3

【參考文獻(xiàn)】

中國(guó)期刊全文數(shù)據(jù)庫 前10條

1 熊勇;;高密度電法勘探中地形影響校正方法探討[J];人民長(zhǎng)江;2014年14期

2 麻昌英;柳建新;劉海飛;郭榮文;;復(fù)雜地形下高密度激電法2.5維有限單元法數(shù)值模擬[J];物探化探計(jì)算技術(shù);2014年04期

3 劉海飛;阮百堯;柳建新;呂玉增;;起伏地形電導(dǎo)率連續(xù)變化的三維激電數(shù)據(jù)有限元數(shù)值模擬[J];物探化探計(jì)算技術(shù);2008年04期

4 簡(jiǎn)興祥;王緒本;楊利容;高永才;;高密度電阻率法地形影響校正[J];物探化探計(jì)算技術(shù);2008年04期

5 孫建國(guó);;復(fù)雜地表?xiàng)l件下地球物理場(chǎng)數(shù)值模擬方法評(píng)述[J];世界地質(zhì);2007年03期

6 呂玉增;阮百堯;;復(fù)雜地形條件下四面體剖分電阻率三維有限元數(shù)值模擬[J];地球物理學(xué)進(jìn)展;2006年04期

7 吳小平;非平坦地形條件下電阻率三維反演[J];地球物理學(xué)報(bào);2005年04期

8 楊華,李金銘;起伏地形對(duì)近礦圍巖充電法影響規(guī)律的數(shù)值模擬研究[J];物探與化探;1999年03期

9 阮百堯,村上裕,徐世浙;電阻率/激發(fā)極化率數(shù)據(jù)的二維反演程序[J];物探化探計(jì)算技術(shù);1999年02期

10 劉繼東;用異常電位邊界單元法做電測(cè)深資料地形改正[J];煤田地質(zhì)與勘探;1998年03期

，

本文編號(hào)：2434008