EH4 Electromagnetic Imaging System Data Processing Method And Applied Research To Improve The Detection Of Tunnel

Yongtaiwen Ruian to Cangnan pipeline highway projects will run through the best from Wenzhou industrial base and economic vitality of the strongest in the eastern coastal area, which is a national key construction projects eastern coast. The highway section is located in the southern coastal city of Wenzhou, Zhejiang Province, with many multi-junction of Fujian Province, tunnels, complicated geological conditions. The segment elevation mostly large tunnel, and up to 520 m, therefore, such as high-density electrical geophysical methods can not reach target depth, difficult construction. Considering the economic and other factors determine the efficiency of the use of electromagnetic sounding system EH4 the geophysical exploration work. EH4 as an efficient audio magnetotelluric sounding method, supplemented by a small artificial emission source, a high-frequency signal energy to make up for the lack of natural electromagnetic fields. Because the entire instrument has lightweight and efficient work efficiency, and therefore is widely used in many fields in recent years, hydrology, engineering geology and exploration of mineral resources exploration, etc., and have achieved good results. However, as a single system denoising means EH4 limitations large and data processing is closed and is not conducive to improving human intervention, so that the data processing system often results EH4 affected by various strong interference noise, resulting in reduced reliability Although the construction process in the field can be superimposed by increasing the number and improve the artificial source of transmit power and extend the observation time and other measures to suppress interference, but under strong interference noise effects of these methods are very poor.In this thesis, the above problem as the center, a new improved method. This paper first described the basic principles of EH4 Electromagnetic Imaging System, the traditional data processing and collecting data file structure, in the full understanding of the proposed non-parametric test method on the basis of the entire system- Runs test method. This method uses time-domain data stationary test to identify non-stationary items as interference removed; In the process of estimating the power spectrum with Hamming window spectrum frequency spectrum instead of the giant window smooth, narrow the scope of the flying spot, improve the frequency spectrum estimation accuracy; For high-frequency harmonic interference effects of interference bands using the right setting is zero, then the estimated value of the band obtained by interpolation. Yongtaiwen Ruian to Cangnan pipeline highway projects has used the improved methods applied for data processing, data interpretation obtained better results map.Meanwhile EH4 data Hangxinjing Jiande to civilized white sand off highway projects were processed similarly obtained better results map data interpretation. By drilling and other geological data and information are two projects demonstrate the adoption of improved methods for data processing with high credibility. Achieve research purposes.