ISSN: 1945-7545
CODEN: GTJODJ
Page Count: 7

The Application of Time Domain Reflectometry in Geotechnical Instrumentation

Look, BG
Postgraduate studentengineer, University of QueenslandMaterials and Geotechnical Services Branch, Transport Technology Division, Queensland Department of Transport,

Reeves, IN
Principal advisor of the Materials Development Section, Materials and Geotechnical Services Branch, Transport Technology Division, Queensland Department of Transport,

Abstract

The performance of road pavements and earth structures is dependent on the moisture regime experienced during their service life. One of the practical challenges in understanding moisture regimes in earth structures has been to continuously monitor moisture fluctuations in a nondestructive and reasonably accurate way. The time domain reflectometry (TDR) device shows considerable promise in overcoming many of the drawbacks of traditional techniques. The TDR measures the volumetric moisture content of the soil via a buried sensor (probe). Probes can be buried and monitored remotely, and an immediate result can be obtained.

This paper outlines the principles of the TDR device and its mode of operation. Brief details are presented on the experience gained using the TDR on embankment installations, which are currently being monitored. Scope exists for its wider application in the general field of geotechnical instrumentation.

Keywords:
time domain reflectivity, volumetric moisture content, soil dielectric, field testing, remote monitoring, expansive clay embankments

Paper ID: GTJ10024J
DOI: 10.1520/GTJ10024J
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