This presentation is intended to provide background on the principles involved in geotechnical and infrastructure applications of Time Domain Reflectometry (TDR). TDR is basically radar in which a voltage pulse is launched along a coaxial cable. A reflection ...

Soil water measurement methods encounter particular problems related to the physics of each method. For TDR, these relate to wave form shape changes caused by soil, soil water, and TDR probe properties. Methods of wave form interpretation that overcome these ...

Many options are available for monitoring unstable slopes. The remote location of many unstable slopes has created a need for systems that can be accessed remotely and provide immediate warning in case of a failure. Advances in electronic instrumentation, ...

Time domain reflectometry (TDR) is used to determine embankment slope movement and piezometric levels easily, safely and economically. The digital nature of the data allows remote monitoring by telemetry. A cable tester sunds a waveform down a coaxial cable ...

The author's research and experience suggest a number of additional geotechnical monitoring applications for TDR. For example, foam or air filled coaxial cables can be used to monitor groundwater levels. The presence of water in the dielectric produces a characteristic ...

Time domain reflecometry (TDR) was originally developed to find breaks in power and communication cables. When a coaxial cable is deformed, the impedance characteristics of the cable change. Changes in impedance are noted as changes in the characteristic TDR ...

The landslide is occurring in rocks of the Franciscan Complex. In the area of the roadway it moves on the order of 1.5 to 3.0m/yr. Two inclinometers were installed in the slide to determine the depth to the failure plane(s). One of the inclinometers is located ...

The use of time domain reflectometry (TDR) to monitor movement in embankments and slopes is an emerging technology. TDR was originally developed for the telecommunication industry to locate breaks in cables. TDR is a time dependant pulsing electronic signal ...