Study On Geological Radar Technology In Lan-Yu Railway Tunnel Construction

Into the twenty-first century, along with the implementation of the "long-term railway network planning" and the railway high standard large-scale construction smoothly, China has further increased its investment in railway construction, so the domestic high-speed rail has been great and fast development. To meet the technical requirements of high-speed railway in complex terrain regions, require a large number of the construction of tunnels and bridges. This paper studies the application of geological radar in the tunnel construction. In the tunnel excavation process, we need to know in advance the geological changes in front of face for the tunnel to provide a more accurate geological data in order to rationally adjust the construction plan in time and the tunnel construction and excavation process. To strengthen security, prevention and protection measures to avoid engineering accidents. In addition, in the process of construction, quality evaluation and quality test after completion needs to be detailed, accurate and comprehensive grasp of the tunnel with or without quality defects.Ground Penetrating Radar belongs to the geophysical exploration method, which is the application of high frequency electromagnetic pulse signal reflection to detect the front and the distribution of underground medium. Because of its scanning speed, high resolution, light weight, nondestructive testing(NDT), image direct advantages, advance geological forecast in tunnel and the lining testing has been widely used.The application of Ground Penetrating Radar is based on the theory of electromagnetic field. Electromagnetic field theory and the electromagnetic wave propagation rule is the theoretical basis of ground penetrating radar technology. This article obtains from the maxwell’s equations and understand the basic theory of electromagnetic field. Besides, this paper introduces the electromagnetic wave propagation characteristics in different mediums and discusses the geological radar detection rule under different medium and the electromagnetic characteristics of the medium. By learning about the ground penetrating radar application technology research materials at home and abroad, combined with the widely applied in the Lan (lanzhou) Yu (chongqing) railway tunnel advance geological prediction and lining testing, has accumulated rich experiences in application of Ground Penetrating Radar technology. This article mainly has the following contents:(1) This paper expounds the basic theory of electromagnetic wave, including maxwell’s equations and the wave equation, dipole antenna electromagnetic field, electromagnetic field and so on.(2) This paper systematically summarizes the application of Ground Penetrating Radar data acquisition methods and data processing procedure, and details the data collection and preparation, the matters needing attention in the process of gathering and acquisition after data processing, etc.(3) Through the study of the advanced detection of tunnel geological forecast, rock type and the design is verified whether conform to and scientifically determine the tunnel geological condition to better adjust the construction methods for subsequent construction safety provide necessary technical support and design changes.(4) Based on the tunnel construction of inverted arch and filling and the secondary lining of non-destructive testing, the problem is discovered early. So, renovation and corrective measures are taken to eliminate hidden dangers and make sure the real-time monitoring of the tunnel construction.