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原文传递 Evaluation of Two Monitoring Systems for Significant Bridges in Texas. Research rept.

题名：	Evaluation of Two Monitoring Systems for Significant Bridges in Texas. Research rept.
作者：	BILICH, C. T.; WOOD, S. L.
关键词：	Texas-; Bridges-; *Monitoring-.;Bridge-inspection; Global-positioning-system; Data-acquisition; Testing-; Quantitative-analysis.
摘要：	Within the past twenty-five years, several important bridges have been constructed within the State of Texas which utilize relatively uncommon structural systems, such as cable-stayed superstructures or posttensioned box girders. Because of their unique designs, the Texas Department of Transportation (TxDOT) is concerned that the structural response of these bridges may be different than the vast majority of bridges in the state and that standard inspection techniques may not be sufficient to detect the onset of structural damage. TxDOT project 0-4096, Structural Health Evaluation and Monitoring of Major and Unique Bridges in Texas, was funded to identify and evaluate monitoring technologies that could provide information about the behavior of these unique bridges that is not available during routine inspections. Two monitoring systems for bridges were evaluated for use by the Texas Department of Transportation. The first system was designed to increase the quantitative information obtained during a routine inspection of a steel bridge. The miniature, battery-powered data acquisition system selected for study has the ability to record a single channel of strain data and use a rainflow counting algorithm to evaluate the raw data. This system was considered to be particularly useful for evaluating fracture critical bridges. The second system provided long-term monitoring of bridge displacements using global positioning systems (GPS). The accuracy threshold of the GPS data was found to be 3 to 4 mm when the data were averaged for 24 hr. Significantly larger errors were observed for shorter averaging durations when satellite coverage was poor. Both monitoring systems are evaluated in this report.
报告类型：	科技报告