甘肃北山新场地段花岗岩体展布及内部结构电磁法探测
发布时间：2019-06-02 03:22
【摘要】：我国开展高放废物地质处置研究有20多年的历史,在处置库地质选址中,已经把甘肃北山新场地段的花岗岩体作为重点选址区域加以研究,业已取得了许多重要的地质研究成果。为了对该区深部岩体进行安全性和稳定性评价,进一步探明岩体的结构和控制岩体的构造是今后地球物理勘查的主要目的。本文结合核工业地质局高放废物地质处置研究开发项目,以甘肃北山新场地段花岗岩为研究对象,开展以大地电磁测深为主的深部地球物理勘查工作,为预选区场址特性评价提供科学依据。在野外数据采集中选用混场源高频电磁法和大地电磁法两种测量方式,获得了大量的大地电磁测深实测资料,在对实测数据进行预处理的基础上,采用一维OCCAM算法进行反演计算,获得了研究区各条测线的电阻率反演剖面。结合剖面附近的钻孔资料和地质条件对每条电阻率剖面进行推断解释。分析表明,电阻率异常较好地反映了发育于岩体内部或岩体边界处断裂构造的分布情况和产状特征,据此确定了新场地段两个主要目标岩体(新场岩体和芨芨槽岩体)的空间展布形态,并对岩体的完整性进行了评价。研究结果表明,由于大多数分布于新场地段花岗岩体内部的构造破碎带向下切割深度小于300m,说明对深部岩体的破坏性较小,岩体的完整性较好。考虑到在野外数据采集过程中,常常受到各种干扰因素的影响,加上纪录时间长短的限制,造成了数据的分散、跳跃或突变,为了消除干扰,在数据处理过程中,对滤波去噪方法和应用效果进行了研究。引入中值滤波去噪方法,尝试对MT电磁测深剖面上多个受干扰较严重测点上的实测数据进行去噪滤波,为了取得最佳的处理效果,分别选取多个滤波窗口,进行对比试验,结果表明,二维窗口[4×4]更能有效地阻止“飞点”异常,并且对大的电性变化不会产生平滑,可作为电磁测深数据降噪的最佳窗口,为后续数据处理奠定了理论基础。
[Abstract]:The research on geological disposal of high-level radioactive waste in China has been carried out for more than 20 years. In the geological location of disposal reservoir, the granite body in Xinchang area of Beishan, Gansu Province has been studied as the key site selection area. Many important geological research achievements have been made. In order to evaluate the safety and stability of the deep rock mass in this area, it is the main purpose of geophysical exploration in the future to further find out the structure of the rock mass and control the structure of the rock mass. In this paper, based on the research and development project of high level radioactive waste geological disposal in the Bureau of Nuclear Industry Geology, taking granite in Xinchang area of Beishan, Gansu Province as the research object, the deep geophysical exploration based on magnetotelluric bathymetric survey is carried out. It provides a scientific basis for the evaluation of site characteristics in pre-selected areas. In the field data acquisition, mixed field source high frequency electromagnetic method and magnetotelluric method are selected to obtain a large number of measured magnetotelluric bathymetric data, and on the basis of preprocessing the measured data, The one-dimensional OCCAM algorithm is used for inversion calculation, and the resistivity inversion profiles of each measuring line in the study area are obtained. Based on the drilling data and geological conditions near the section, each resistivity profile is inferred and interpreted. The analysis shows that the electrical resistance anomaly reflects the distribution and occurrence characteristics of fault structures developed in the rock mass or at the boundary of the rock mass. Based on this, the spatial distribution patterns of two main target rock masses (Xinchang rock mass and Achnatherum splendens trough rock mass) in Xinchang area are determined, and the integrity of rock mass is evaluated. The results show that because most of the structural fracture zones distributed in Xinchang area are cut down by less than 300m, the damage to deep rock mass is less and the integrity of rock mass is better. Considering that in the process of field data acquisition, it is often affected by various interference factors, coupled with the limitation of recording time, resulting in the dispersion, jump or mutation of the data. In order to eliminate the interference, in the process of data processing, The filtering denoising method and its application effect are studied. The median filter denoising method is introduced to Denoise the measured data at several seriously disturbed measuring points on the MT electromagnetic bathymetric profile. in order to obtain the best processing effect, several filtering windows are selected and the comparative experiments are carried out. The results show that the two-dimensional window [4 脳 4] can effectively prevent the "flying point" anomaly and will not smooth the large electrical change. It can be used as the best window for noise reduction of electromagnetic bathymetric data, which lays a theoretical foundation for subsequent data processing.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.325;TL942.1
本文编号：2490795
[Abstract]:The research on geological disposal of high-level radioactive waste in China has been carried out for more than 20 years. In the geological location of disposal reservoir, the granite body in Xinchang area of Beishan, Gansu Province has been studied as the key site selection area. Many important geological research achievements have been made. In order to evaluate the safety and stability of the deep rock mass in this area, it is the main purpose of geophysical exploration in the future to further find out the structure of the rock mass and control the structure of the rock mass. In this paper, based on the research and development project of high level radioactive waste geological disposal in the Bureau of Nuclear Industry Geology, taking granite in Xinchang area of Beishan, Gansu Province as the research object, the deep geophysical exploration based on magnetotelluric bathymetric survey is carried out. It provides a scientific basis for the evaluation of site characteristics in pre-selected areas. In the field data acquisition, mixed field source high frequency electromagnetic method and magnetotelluric method are selected to obtain a large number of measured magnetotelluric bathymetric data, and on the basis of preprocessing the measured data, The one-dimensional OCCAM algorithm is used for inversion calculation, and the resistivity inversion profiles of each measuring line in the study area are obtained. Based on the drilling data and geological conditions near the section, each resistivity profile is inferred and interpreted. The analysis shows that the electrical resistance anomaly reflects the distribution and occurrence characteristics of fault structures developed in the rock mass or at the boundary of the rock mass. Based on this, the spatial distribution patterns of two main target rock masses (Xinchang rock mass and Achnatherum splendens trough rock mass) in Xinchang area are determined, and the integrity of rock mass is evaluated. The results show that because most of the structural fracture zones distributed in Xinchang area are cut down by less than 300m, the damage to deep rock mass is less and the integrity of rock mass is better. Considering that in the process of field data acquisition, it is often affected by various interference factors, coupled with the limitation of recording time, resulting in the dispersion, jump or mutation of the data. In order to eliminate the interference, in the process of data processing, The filtering denoising method and its application effect are studied. The median filter denoising method is introduced to Denoise the measured data at several seriously disturbed measuring points on the MT electromagnetic bathymetric profile. in order to obtain the best processing effect, several filtering windows are selected and the comparative experiments are carried out. The results show that the two-dimensional window [4 脳 4] can effectively prevent the "flying point" anomaly and will not smooth the large electrical change. It can be used as the best window for noise reduction of electromagnetic bathymetric data, which lays a theoretical foundation for subsequent data processing.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.325;TL942.1
【参考文献】
相关期刊论文 前1条
1 刘林清;遥感技术在高放废物处置库场址预选中的应用[J];遥感技术与应用;1994年02期
，本文编号：2490795
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2490795.html
