Real-time monitoring of large scale structures

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Bridges in Canada are exposed to environmental and man-made conditions that can lead to premature damage and deterioration of structural components.  A proactive rehabilitation strategy requires the ability to detect damage when it is relatively minor, and to assess the load-carrying capacity of members constructed with materials that may not conform to current specifications.     Vibration measurement techniques are currently being investigated at the University of Saskatchewan to detect damage at a very early stage.  Even minor damage results in changes to the vibration characteristics of a bridge.  If these changes can be detected, it may be possible to identify locations of damage when it is relatively minor.  Both laboratory and field measurements are being conducted.  Future research also includes the field-instrumentation of bridges nearing the end of their useful service life.  Monitoring such structures will provide a level of assurance that they continue to perform reliably.     Historical structures built using plain steel reinforcement are now in need of rehabilitation.  Although the fundamental axial response of these members is known, the characteristics of bond between the plain reinforcing bar and the surrounding concrete are not well understood.  Heavily instrumented plain reinforcing bars in pullout and flexural specimens are being used to evaluate the mechanics of bond.  Simultaneous sampling of the instrumentation in flexural members is required to identify the mechanism initiating failure, and to capture the deterioration of bond with increasing slip at the unloaded end of the bar in pullout specimens.     Both of these projects require data acquisition equipment (DAE) that is capable of sampling readings from a large number of sensors simultaneously, both in the laboratory and at various field locations.  The DAE at the University of Saskatchewan does not currently have sufficient capacity.  The requested equipment will expand the data acquisition system devoted to research from sixteen to eighty eight simultaneous sensors.