Since it became possible to calculate the specific design-build needs of bridges with increasing accuracy in the 19th century, and new materials—beginning with cast iron and steel, followed by reinforced and prestressed concretes—also became available to build them, the number of bridges constructed all over the world has increased. It is evident today that many of these bridges have aged considerably, conditions which often lead to collapse despite regular inspections and repairs. The Fern Hollow Bridge in Pittsburgh, an approximately 440-foot-long, three-span steel bridge over a forest ravine, collapsed in January 2022. Fortunately, no fatalities occurred, although several vehicles, including a bus, were involved in the collapse.

How can accidents of this nature be avoided, and which technologies are available to protect bridges more effectively? Bridges all over the world can be efficiently monitored with weigh in motion (WIM) and structural health monitoring (SHM), extending their service life and, in a worst-case scenario, preventing their collapse.

Reprinted courtesy of Christoph Klauser, Construction Executive, a publication of Associated Builders and Contractors. All rights reserved.