Tunnel Lining Layer In The Automatic Identification, Ground-penetrating Radar Imaging

In the tunnel structure, quadric lining is a framework which is subjected to pressure from rock, sustaining, antisepticising and waterproofing etc. In the tunnel construction, it may cause a phenomenon that the real thickness of tunnel lining can't come to the designing standard due to the complicated geological condition, bad construction environment, nonstandard construction craft and undemanding procedure throughout in construction, which may result in the danger of quality in construction for safe operation of expressway. Therefore, the thickness of quadric lining is often an important content in the quality inspection for the highway tunnel buildings.At present, the data interpretation to inspect the thickness of quadric lining mainly depends on the personal experience from the interpreters.The article first discusses the principle of the thickness detection to quadric lining by GPR. Then, it introduces the methods of image reconstruction algorithms, clutter depression and thickness measurement. On the condition of understanding the materials from geology, design and construction, it is the way with which the interpreters make the analysis and recognize the features of quadric lining according to the characteristics of inphase axis, amplitude, waveform and frequency. This article realizes these functions, such as getting the working parameters and data records from original files by programming with MATLAB, imaging in A-scan and B-scan form, reconstructing the constitution of tunnel building, suppressing the noise signals and tracking the thickness of quadric lining of tunnel. At last, measuring the thickness and assessing the quality of Longhai.