In order to detect the voids and compactness around jacked pipes, a field survey and experiments were carried out to detect the voids around cement and steel pipes in an engineering case with a ground penetrating radar (GPR). A theoretical model for simulating the voids around the cement and steel pipes was established, and forward modeling of the GPR was conducted with the two?dimensional finite element method. The results show that the GPR is effective in detecting the voids around the cement pipes. However, it is not effective in detecting the voids around the steel pipes, because the multiply reflected signals between the radar antenna and pipe wall are strong. It is determined that it is feasible to use GPR to detect the voids around cement pipes. Meanwhile, for the detection of voids around cement pipes, new nondestructive examination methods and new types of equipment have to be developed in order to obtain better application effects.