Proc. SPIE. 8347, Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2012
KEYWORDS: Infrared imaging, Finite-difference time-domain method, Reflection, Computer simulations, 3D modeling, Finite element methods, Antennas, Acoustics, Ground penetrating radar, General packet radio service
To evaluate the potential of detecting leakage of water pipes using ground-penetrating radar (GPR), a lab experiment is
conducted as well as numerical modeling. In the experiment, an artificial 'leakage' is put under, beside and above a pipe
buried in dry soil, simulating different leakage locations. By scanning such an experimental model using commercial
GPR, more understanding is gained regarding the signature of leakage in GPR profile. Compared to a distinct hyperbola
as shown in GPR profile of intact pipes, the leakage zone is disturbed by the wave reflections caused by saturated soil.
Furthermore, a numerical model is constructed to simulate such a phenomenon. Maxwell's equations, permittivity
distribution of dry and saturated soil, and artificial absorbing boundary conditions are the three key points of such a
model. Numerically simulated results seem to be in agreement with experimental results. And the signature of leakage is
also visible in the simulated GPR profile. Therefore, GPR survey seems to be promising as an efficient and
nondestructive remote leakage detection approach. And the effects of background inhomogeneity and ground-surface
roughness can be investigated in future using such an experimental or simulation approach.