Principles of time domain reflectometometry applied to measurement of rock mass deformation

摘要: Abstract Time Domain Reflectometry (TDR) is an electrical pulse testing technique originally developed to locate faults in coaxial power transmission cables. Recently, this has been adapted for monitoring deformation of cables grouted into rock masses. Rock mass movements deform the cable, which locally changes cable capacitance and thereby reflected wave form voltage pulse. By these reflection signatures, it possible monitor both local extension shearing. This paper concentrates on electromagentic theory necessary quantitatively relate geometry signatures. A finite element model employed numerically simulate deformed geometries produced laboratory, effect signal attentuation resolution two deformities assessed basis laboratory test results. Finally, models are extract heretofore unrealized information from previously collected field data.