Performance monitoring of deep excavations typically includes slope inclinometers, optical surveying of soil deformation, tiltmeters and strain gages. Current monitoring data collection and processing requires time consuming site visits and manual data reduction by project engineers. Development of robotic and remote access geotechnical instrumentation conceptually allows processed data to be...
This paper describes developments of integrated tools for predicting, monitoring, and controlling ground movements associated with excavations in urban areas. Successful use of monitoring data to update performance predictions of supported excavations depends equally on reasonable numerical simulations of performance, the type of monitoring data used as observations, and the...
Northwestern University developed copper-precipitation-hardened, high-performance weathering steel (NUCu 70W Steel) that is produced by hot rolling after casting and then air-cooling. Due to simple processing the steel is fabricated at lower cost than competing high-performance steels that require quench and tempering. NUCu 70W steel can be easily welded without pre-...
Experimental Time Domain Reflectometry (TDR) data obtained from the field are compared with numerical simulations using a finite-difference solution of the transmission line equations. The model simulates transmission of a voltage pulse along a lossy coaxial cable where deformities on the cable, such as crimps and shears, are represented by...
Time Domain Reflectometry (TDR) is a versatile technology amenable to a variety of measurements and nondestructive monitoring of infrastructure conditions. It can be utilized to monitor deformation of soil/rock and structures, monitor changes in fluid levels, and monitor water content of soils. Furthermore, this monitoring can be automated using systems...
Two longwall coalmine panels were mined at a depth of approximately 156 m (510 ft) beneath I-70 east of Washington, Pennsylvania such that it crossed the width of one panel at two locations. The Pennsylvania Department of Transportation (PennDoT) assumed responsibility for real time monitoring of both ground deformation and...
This paper reviews the new field of geo-measurement with metallic cable time domain reflectometry (TDR) for surveillance of transportation facilities. TDR is radar in a coaxial cable, and is especially advantageous for remote monitoring because of its inherently digital nature. Advances can be separated into those that leverage use of...
This thesis combines field and laboratory measurements with three dimensional (3D) finite element analysis (FEM) to demonstrate the use of Time Domain Reflectometry (TDR) cable-grout composites to measure localized shearing in soft soil. Past field installations of TDR cable-grout composites in rock have lead to its widespread use in the...
This thesis presents the application of Time Domain Reflectometry technology in nine case studies. Presented in detail are cable and grout installation techniques, data acquisition instrumentation and autonomous real time monitoring of soil deformation using TDR. The goal of this work is to summarize the state of the technology in...