Akademik Veri Yönetim Sistemi
Yerbilimleri/ Earth Sciences, cilt.30, sa.1, ss.45-57, 2009 (Scopus)
The aim of this study is to prove that the parameters of location, size and the physical characteristic of buried pipes can be determined by a ground penetrating radar (GPR) method with laboratory and field applications. In the first place, laboratory tests on three different models were run, and the ground penetrating radar data was acquired on models using the RAMAC CU II system and a shielded antenna with a 1.6 GHz center frequency. Then, field studies were performed in Babür Street, Alti{dotless}ndaǧ Town, Gültepe District in the province of Ankara, using shielded antenna with a 500 MHz center frequency. After data processing, the reflected/diffracted electromagnetic (EM) wave fields were analysed on the radargrams belonging to those profiles which were parallel and perpendicular to the direction of pipes. Thus, the locations, depth, size and physical properties (types) of the pipes were determined on the known models and on the street, including no previous knowledge. The results show that locations of the reflected/diffracted electromagnetic (EM) wave fields on the processed radargrams define the locations and depths of the pipes. The widths of the hyperbola apexes of the diffracted wave field coming from the pipes delineate the size of the pipes. The type of pipes can be determined by comparing the polarity differences between the direct EM wave, which moves from transmitter to receiver along the ground, and the reflected/diffracted wave fields coming from the pipes. A second indicator of pipe type is that the diffracted wave amplitudes of iron pipes are bigger than the diffracted wave amplitudes of plastic pipes, because of the reflection coefficients, and therefore the diffracted hyperbolas of iron pipes are seen more clear.