Up-hole reflectometry devices that interrogate passive mechanical transducers are increasingly used in geotechnical instrumentation. One of such a monitoring technique is the time domain reflectometry (TDR). This study utilizes the principle of TDR to devise ...

<p>Using convergence tape for measuring rock movement in a tunnel during construction to control the stability of the excavation is a common practice. In this technique a number of reference points (convergence pins) are installed around the tunnel periphery. ...