Monitoring cracks and prestress-loss in PSC girder bridges using vibration-based damage detection techniques

Abstract

In this study, a vibration-based method to simultaneously predict prestress-loss and flexural crack in PSC girder bridges is presented. Prestress-loss and flexural crack are two typical, but quite different in nature, types of damage which can be occurred in PSC girder bridges. The following approaches are implemented to achieve the objective. Firstly, two vibration-based damage detection techniques which can predict prestress-loss and flexural crack are described. The techniques are prestress-loss prediction model and mode-shape-based crack detection method. In order to verify the feasibility and practicality of the techniques, two different lab tests are performed. A free-free beam with external unbonded tendons is used to verify the feasibility of the prestress-loss prediction model. In additional, a PSC girder with an internal unbonded tendon is used to evaluate the practicality of the prestress-loss prediction model and the modeshape-based crack detection method.

LiDAR-BASED BRIDGE STRUCTURE DEFECT DETECTION

“…Cracking in concrete members, in particular, is most common as a result of either excessive loading or environmentally induced internal stressing (such as erosion or corrosion of rebars). Significant research efforts have been spent in the detection of cracking in concrete 9–12 . Scaling, spalling, and efflorescence are largely due to environmental effects and typically result in material mass loss.…”

“…Significant research efforts have been spent in the detection of cracking in concrete. [9][10][11][12] Scaling, spalling, and efflorescence are largely Using a LiDAR scan to detect surface defects of a bridge, a reference plane is necessary to simulate the intact condition of the bridge surface. The scanner records 3D positions of the bridge component, which is limited to the surface points.…”

Experiment of the monitoring prestress loss of prestressed concrete beams with damages under static loading

“…Nearly 10,000 small prestressed beam bridges were built in China at the end of the 20th century with a wide range of crack expansion problems. Their safety assessment and bearing capacity calculation had no basis because of the inability to get the prestressed state of steel bars or steel strands, which has become an astriction of engineering worldwide [8][9][10][11][12][13][14][15][16]. Therefore, analyzing the evolution law of prestress loss in different damage stages of prestressed concrete beams under static load is essential.…”

Full-Scale Prestress Loss Monitoring of Damaged RC Structures Using Distributed Optical Fiber Sensing Technology

“…Wang et al [ 10 , 11 ] developed magneto-elastic sensors to monitor the stress in a multi-strand-cable system, then applied these sensors on the Qianjiang 4th bridge to monitor the stresses of key hanger cables and post-tensioned cables. Kim et al [ 12 ] presented a vibration-based method to simultaneously predict prestress loss and flexural cracking in PSC girder ridges. Barr et al [ 13 , 14 ] monitored the behavior of five prestressed concrete girders made with high-performance concrete using vibrating-wire strain guages over a period of approximately three years.…”