URBAN CONCRETE BRIDGE STRUCTURES IN THE CZECH REPUBLIC AND THEIR MONITORING BY ACOUSTIC EMISSION AND NONLINEAR ULTRASONIC SPECTROSCOPY

ABSTRACT

Bridges in urban areas often constitute architectural dominant features of particular cities. In general, while an arrangement of bridges in rural areas prefers technical points of view, in case of urban bridges esthetical or architectural perspective plays important role as well. It causes non-unified solutions and more complicated structures, frequently with very knotty details. Such structures cannot be monitored using conventional methods as shown in an example of the fallen footbridge in Prague recently. The footbridge was monitored continuously several years before its falling using continuous measurement of its sag. The paper introduces arrangement of selected urban bridges in the Czech Republic and explains employment of monitoring methods based on acoustic emission and nonlinear ultrasonic spectroscopy of reinforcing bars or tendons placed inside of concreate bridge structures by way of updated technical standard. The methods are able to evaluate condition or damage progression of a relatively complex bridge structures and help to predict its behavior in the future.

Keywords: damage progression, acoustic emission, concrete bridge, corrosion, degradation