An experimental study on a ground-penetrating radar for detecting water-leaks in buried water transfer pipes

In this paper, the feasibility of ground penetrating radar (GPR) probing technology was experimentally investigated. Polyvinyl chloride (PVC) tank filled with dry and homogeneous sand is installed in the laboratory. Within meaningful frequency band of the transmitting signal, the electrical properties of the material under test (MUT), such as dry sand and acryl used in experiment, are measured by using an open-ended coaxial probe method. The electrical properties of the drysand are similar to that of acryl. Therefore, to maintain precise position of the buried targets, support is made of acryl and filled with the dry sand. Leaking water could saturate the surrounding medium of leaky pipes. In experiment, however, it is very difficult to maintain moisture content and distribution of wet sand. Equivalent model instead of wet sand is necessary. The electrical property of the wet sand under saturation is very alike that of methanol. Therefore, the box is made of acryl plates and filled with methanol. The box with methanol filling is equivalently considered as water leakage model. We perform B-scan surveys with various situations. And we have investigated the possibility of GPR on detection water leakage as well as the pipe.