Sustainability Report 2018

Continuous monitoring of bridge safety

Bridges are the trouble spots of any transport system. If they become impassable to pedestrians and/or vehicles, traffic chaos will result in no time. In the worst case, a bridge can collapse entirely, with catastrophic consequences.

Based on the analysis of acoustic emissions, Bilfinger has designed a process that allows bridges to be monitored continuously. The concept is simple: Every hairline crack or minute change in the fabric of a building structure emits sonic signals. By capturing these signals using high-tech sensors and corresponding software programs, it is possible immediately to detect changes in the structure’s substance.

“With this technology, we are taking the inspection of bridges to a new level,” says Ronald Hepper, CEO of Bilfinger Noell. “This method puts us in a position to detect and precisely locate any damage to a structure in a timely manner. Even under challenging environmental conditions such as frost, heat, vibrations or ambient noise, we can use intelligent sound-emission analysis to identify, analyze, and monitor any and all events in a bridge structure as they occur.”

The technology is already being tested at a viaduct near Fulda, Germany, as part of a pilot project jointly conducted with the competent public transport company. In the course of the monitoring process, the transport authority receives a continuous feed of online information about the condition of the structure.

“We analyze the bridge’s ongoing operations by means of a self-developed program that runs around the clock. It is able to interpret the signals coming from the viaduct, such as sounds or temperature emissions, with the aid of sensors attached to the structure and classifies them using a traffic-light system. This technology enables us to not only make bridges safer – it also makes a contribution towards extending their useful lives,” says Hepper.