EH4电磁成像系统数据处理方法改进及在隧道探测中的应用研究

发布时间：2018-01-17 19:37

本文关键词：EH4电磁成像系统数据处理方法改进及在隧道探测中的应用研究　出处：《东华理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：甬台温高速公路复线瑞安至苍南段工程将贯穿起温州产业基础最好、经济活力最强的东部沿海区域,它是国家东部沿海重点建设工程。该高速公路段地处温州市南部沿海地区,浙江省与福建省交界处,隧道众多,地质情况复杂。该段大多隧道高差大,最大达到520m,因此高密度电法等物探方法达不到目标深度,难于施工。综合考虑经济和工作效率等因素决定使用EH4电磁测深系统进行此次物探探测工作。EH4作为一种高效的声频大地电磁测深方法,辅以小型的人工发射源,弥补了天然电磁场的高频信号能量的不足。由于整套仪器具有轻便和高效的工作效率,因此近年来被广泛应用于水文、工程地质勘查以及矿产资源勘查等众多领域,并取得了较好的效果。但由于EH4系统的去噪手段单一,局限性大,且数据处理流程封闭,不利于人工过多干预与改进,因此EH4系统的数据处理结果往往会受到各种强干扰噪声的影响,导致可信度降低,虽然在野外施工过程中可以通过增加叠加次数、提高人工源的发射功率以及延长观测时间等措施来压制干扰,但是在强干扰噪声下这些方法的效果都会很差。本论文以上述问题为中心,提出了新的改进方法。本论文首先详述了EH4电磁成像系统的基本原理、数据处理流程和采集数据的文件结构,在充分了解了整个系统的基础上提出了非参数检验法——游程检验法。采用此方法对时间域数据进行平稳性检验,找出非平稳项视为干扰剔除;在估算功率谱过程中以海明窗谱代替矩形窗谱进行频率平滑,缩小飞点的影响范围,提高频率谱估算精度;对于工频干扰的高次谐波影响,采用设置干扰频段的权值为0,然后通过内插法求出该频段估计值。在甬台温高速公路复线瑞安至苍南段工程中应用改进方法进行数据处理,得出较好的资料解释成果图,同时对杭新景高速公路建德至开化白沙关工程的EH4数据进行了处理,同样得出了较好的资料解释成果图。通过两个工程的地质资料和钻探等资料验证了采用改进方法进行数据处理具有较高的可行性与有效性,达到研究目的。
[Abstract]:The project from Ryan to Cangnan section of Yongtaiwen Expressway will run through the east coastal area where Wenzhou has the best industrial base and the strongest economic vitality. It is a key construction project in the east coast of the country. The expressway section is located in the southern coastal area of Wenzhou city, the junction of Zhejiang Province and Fujian Province, there are many tunnels, geological conditions are complex. Most of the tunnels in this section have great height difference. The maximum is 520m, so the geophysical prospecting methods such as high-density electric method can not reach the target depth. It is difficult to construct. It is decided to use the EH4 electromagnetic sounding system to do the geophysical exploration. EH4 is an efficient method for acoustic magnetotelluric sounding. The small artificial emitter makes up for the shortage of the high frequency signal energy of the natural electromagnetic field. Because of the portable and efficient working efficiency of the whole instrument, it has been widely used in hydrology in recent years. Engineering geological exploration and mineral resources exploration and many other fields, and achieved good results, but the EH4 system because of the single means of de-noising, limitations, and data processing process is closed. It is not conducive to artificial intervention and improvement, so the data processing results of EH4 system will often be affected by various strong interference noise, resulting in the loss of credibility. Although during field construction, the interference can be suppressed by increasing the number of stacking times, increasing the power of the artificial source and prolonging the observation time. However, the effect of these methods will be very poor under the strong interference noise. This paper focuses on the above problems, and proposes a new improved method. Firstly, the basic principle of EH4 electromagnetic imaging system is described in detail. The data processing flow and the file structure of the data collection are analyzed. Based on the full understanding of the whole system, a non-parametric test method, run test method, is put forward, which is used to test the stability of the time domain data. Find out the non-stationary term as interference elimination; In the process of power spectrum estimation, the rectangular window spectrum is replaced by the hamming window spectrum for frequency smoothing, which reduces the influence range of the flying point and improves the accuracy of frequency spectrum estimation. For the high-order harmonic effect of power frequency interference, the weight value of the interference band is 0. Then the estimated frequency band is obtained by interpolation. The improved method is used to process the data in the project from Ryan to Cangnan section of Yongtaiwen Expressway, and a better result map of data interpretation is obtained. At the same time, the EH4 data from Jiande to Kaihua Baisha pass of Hangzhou Xinjing Expressway are processed. Through the geological data and drilling data of the two projects, it is proved that the improved method is feasible and effective in data processing, and the purpose of the research is achieved.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P631.326;U452.1

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