V8多功能电法工作站在广西长大深埋公路隧道勘察中的应用研究

发布时间：2018-03-30 07:51

  本文选题：V8多功能电法工作站　切入点：CSAMT　出处：《广西大学》2015年硕士论文

【摘要】：广西山区地形变化剧烈、地质条件复杂,尤其是石灰岩地区,断裂、岩溶等不良地质体相当发育,长大深埋隧道勘察通常缺乏有效的物探手段查明深部不良地质体。高密度电法、浅层地震法等方法存在勘探深度小、地形影响大、高阻屏蔽等诸多不足。V8多功能电法工作站具有先进的电磁法功能模块,该技术恰好弥补浅层物探方法的不足。V8电磁探测技术在实际应用中,电磁法测深曲线特征、静态效应、场源效应、电磁干扰、最佳观测方案、电磁法反演等关键技术尤为重要,本文进行了针对性的研究：通过对卡尼亚电阻率、阻抗相位及磁场强度曲线特征研究,掌握了各种地质背景下曲线变化特征、静态效应及近场效应的体现特征、卡尼亚电阻率曲线与阻抗相位曲线关联变化特征、卡尼亚电阻率与磁场强度对地质体敏感性差异特征以及受干扰影响曲线畸变特征等,对数据采集及资料解释具有重要指导意义；对引起静态效应的机制及校正方法进行了深入研究,利用实测数据进行静态效应分析并用CSAMT-3.0软件分别进行了D(五点滤波法)、H(七点滤波法)、Z(中值滤波法)、K(纵向削平曲线平移法)静态校正,经对比分析,认为该软件中值滤波法静态校正效果较好；对场源效应进行了深入研究,以实例进行了近场效应分析和校正,达到了预期效果；对电磁干扰及应对措施进行深入研究；对CSAMT最佳观测方案进行研究,包括场源设计、排列方式、收发距、测量电极距、工作频率等的选择,指出采用最佳观测方案的重要性：既能提高勘探精度又能提高工作效率；对电磁法反演进行了研究,着重研究了CSAMT-SW V3.0软件的Bostick反演、CSAMT模型的拟二维反演及MT模型的二维带地形反演方法特点,以实例对比分析了各种方案的反演效果,山区隧道勘察宜采用CSAMT模型拟二维反演或MT模型二维带地形反演。论文以广西多个隧道勘察为依托,采用V8电磁法探测出各隧道的不良地质体赋存情况及含水性,经钻探及隧道开挖验证,V8探测结果与实际地质情况吻合较好,取得了预期效果。研究表明,V8电磁法较好地弥补了浅层物探方法(如高密度电法、浅层地震法)探测深度浅、陡峻山区适用性差等不足,可有效查明长大深埋隧道地层分布,断层破碎带、岩溶发育带、软弱夹层等不良地质体的赋存情况及含水性,填补了广西区内深埋隧道地质勘探的空白,突出了其在长大深埋隧道勘探中的优越性。
[Abstract]:The topography of Guangxi mountainous area changes dramatically and the geological conditions are complicated. Especially in the limestone area, fault, karst and other bad geological bodies, the geological bodies are quite developed. The exploration of long and deep buried tunnels is usually lack of effective geophysical means to find out the bad geological bodies in depth. The methods such as high density electric method and shallow seismic method have small exploration depth and great influence on topography. V8 multifunctional electrical workstation has advanced electromagnetic function module. This technology can make up for the deficiency of shallow geophysical prospecting method. V8 electromagnetic detection technology is applied in practice, electromagnetic sounding curve characteristic and static effect. The key techniques such as field source effect, electromagnetic interference, optimal observation scheme and inversion of electromagnetic method are particularly important. In this paper, the characteristics of Kania resistivity, impedance phase and magnetic field intensity curve are studied. The characteristics of curve variation, static effect and near-field effect, and the correlation between Kania resistivity curve and impedance phase curve are grasped. The differences between Kania resistivity and magnetic field intensity to geological bodies and the distortion characteristics of the curves affected by interference are of great significance for data acquisition and data interpretation. In this paper, the mechanism and correction method of static effect are deeply studied. The static effect analysis of measured data and the static correction of D (five-point filtering method) with CSAMT-3.0 software are carried out respectively, and the static correction of D (seven-point filtering method) K (vertical flattening curve translation method) is compared and analyzed. It is considered that the software median filter method has a good static correction effect, the field source effect is deeply studied, the near field effect is analyzed and corrected with an example, and the expected effect is achieved, and the electromagnetic interference and countermeasures are deeply studied. This paper studies the optimal observation scheme of CSAMT, including the selection of field source design, arrangement mode, transceiver distance, measuring electrode distance, working frequency and so on. It points out the importance of adopting the best observation scheme: it can not only improve the exploration accuracy but also improve the working efficiency; The inversion of electromagnetic method is studied, and the characteristics of quasi-two-dimensional inversion of Bostick inversion model of CSAMT-SW V3.0 software and two-dimensional terrain inversion of MT model are emphatically studied. The inversion results of various schemes are compared and analyzed with examples. In mountain tunnel exploration, CSAMT model and MT model should be used to simulate 2D inversion or MT model 2-D terrain inversion. Based on the investigation of several tunnels in Guangxi, V8 electromagnetic method is used to detect the occurrence and water content of bad geological bodies in each tunnel. The results of drilling and tunnel excavation verify that the detection results of V8 are in good agreement with the actual geological conditions, and the expected results are obtained. The study shows that the V8 electromagnetic method can make up for the shallow depth of the shallow geophysical prospecting methods (such as high density electrical method, shallow seismic method). The poor applicability of steep mountain areas can effectively find out the occurrence and water content of bad geological bodies, such as strata distribution of long and deep buried tunnels, fault fracture zone, karst developed zone, weak intercalation and so on. It fills in the blank of deep buried tunnel geological exploration in Guangxi area, and highlights its superiority in long and deep buried tunnel exploration.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U452.1;P631.325
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本文编号：1684999