Cable Stays are difficult to inspect in critical areas. Acoustic monitoring provides a 100% volumetric 24/7 inspection. Many DOTs have adopted monitoring and others are actively planning an installation.
The Texas Fred Hartman Bridge was built in 1995. After an early stay failure, TxDOT developed a plan to collect data about the performance of the stay cables, particularly under oscillation, so that an effective retrofit could be designed.
Research with Texas Tech University and Johns Hopkins University started in April 2002, TxDOT implemented full-scale acoustic monitoring to identify damage occurring to the stay cables.
Stays are 8% of bridges cost so TxDOT designed 30 years of acoustic monitoring into the new Corpus Christi Bridge cable stays. This is one example of forward-thinking for bridge preservation.
Genoa Bridge in Italy
For the Ponte Morandi bridge, Acoustic Monitoring would have given warning of the bridge collapse as the Associated Press stated that Italian engineers knew of problems with the Genoa Bridge since 1979.