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 inverse analysis techniques used to minimize the difference between predictions and observed performance. This paper summarizes each of these factors...
Two numerical procedures are described that quantitatively identify a set of constitutive parameters that best represents observed ground movement data associated with a deep excavations in urban environments. This inverse problem is solved by minimizing an objective (or error) function of the weighted least-squares type that contains the difference between...
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...
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...
How can gatekeeping theory in the circulation of cultural objects, including knowledge production, inform the way cultural sociology investigates the role of the producer and the cultural object as “gated” entities? Using the case of producers working under the rubric of “Contemporary African art” to investigate opportunities and restrictions to...
In his essay on Mali, Bruce Whitehouse of Lehigh University shows how failures of elected leaders, state institutions, and external donors can shift power to the streets and an uncertain contest among armed forces.
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...