A simulation study of a Time Domain Reflectometry (TDR) cable with non-standard cross-section

Coaxial cables are used in Time Domain Reflectometry for geotechnical survey and slope stability monitoring. In this work, a cable model with a rectangular outer conductor and cylindrical inner conductor is subjected to shearing simulations, with shearing introduced from the edge and from the corner of the cable. We examine the profile of reflected pulses due to the shearing for the different cable configurations. Simulation results show that the magnitude of the TDR reflection spikes obtained from the edge shear differs from that of the corner shear by 8.00% to 209.09%, depending on the shear displacement. Since the TDR reflection signals vary with shear orientation, this can be exploited to provide additional information on orientation of movement or deformation. Such information may be useful for applications such as landslide detection and slope monitoring.