Radar Image Processing for Detection of Shape of Voids under Concrete Slab

Abstract

Deterioration of pavements or tunnels results primarily from the existence of voids under the pavements or tunnel linings. To detect these voids effectively by non-destructive tests, a method using radar was proposed. In this research, it is investigated to detect the shape of voids by radar image processing. The experiments were conducted to detect voids under concrete slab. From the results, the fundamental algorithm for tracing the voids, improving the horizontal resolution of the object image and detecting shape of objects, was verified.

Experimental and Numerical Research on Voids and Cracks with Geological Radar Method 

“…In order to acknowledge the applicability and accuracy of the GPR equipped with 1400MHz antenna, A. F Siggins and R. J Whitely established a tunnel lining model set with different materials and targets and analyzed the test results [2] . S.K Park, Uomoto T and Michael Scott researched the response characters of steels and voids with different buries in the concrete structure and the bridge panel [3,4] .Yang Yanqing and He Shaohui studied the application and accuracy of GPR non-contact detection with a 400MHz antenna by making a tunnel lining (plain concrete section and reinforced concrete section) setting with voids, incompact backfill [5] . J. P Bergner, Holliger K, Liu Xinsi and Dai Qianwei investigated the numeriral simulation in the finite difference time domain method (FDTD) [6] , researched absorbing boundary conditions to erase the nonphysical reflection and made numerical analysis on the geological radar detection of tunnel lining with the FDTD and absorbing boundary conditions [7][8][9][10][11][12] .…”