Bridges in Ulm and Neu-Ulm: Cracks on Several Structures

Challenge

Multiple structures, one solution

The bridges in Ulm and Neu-Ulm are under constant load from traffic and the environment. Cracks were found on several structures and had to be observed. The task was therefore not one structure but a series of structures, which shifts the requirements: what was needed was a solution that is cost-efficient, flexible and low-maintenance, not the most technically elaborate one.

Solution

Sensors that move with the project

Watertight displacement transducers were installed, cabled to a solar-powered gateway. The solution is therefore watertight, solar-powered and maintenance-free. Crack width and temperature are captured together, so thermal movement can be separated from a genuine change.

Two points make the system economical across several structures. First, installation: the sensors were fitted by the responsible staff themselves, using the supplied mounting fixture. Second, reuse: the sensor can be unscrewed from the mounting plate and redeployed on another structure. Once a crack is resolved, the sensor moves on instead of a new one being procured.

Result

A stock of structures that reports itself

The baseline measurement sits in the software after the initial installation, and every later measurement is always read against this starting condition. Through the online platform, the responsible engineers track crack widths across all structures from a single place, and remote access lets them adjust measuring intervals and reset thresholds without travelling to the structure.

A PDF report with readings and graphical presentation goes out every quarter. This lets those responsible assess the condition and the change of crack widths clearly and comprehensibly.

The project shows how crack monitoring in bridge monitoring also works across a whole stock of structures. If you have several structures to keep an eye on, describe your project to us through our project inquiry.