CASE STUDY - Lake Champlain Bridge


Monitoring Bridges for Signs of Trouble

Originally constructed in the 1920s, the Lake Champlain Bridge was the only bridge connecting New York and Vermont within 100 miles. But after 80 years of operation, engineers had a sneaking suspicion deterioration was taking its toll.

The Challenge

Engineers needed a fast, simple and cost-effective way of determining the safety of the Lake Champlain Bridge. If a replacement was needed, the safety of workers and civilians needed to be guaranteed throughout the process.

The Solution

HNTB, an architecture, engineering, planning and construction firm relied on the CX1 structural response monitor to track temperature, wind and pier movement, as well as sustained environmental and manmade elements. The versatile, all-in-one device continuously mounted on the pier caps so engineers could monitor tilt data to identify any sudden movements or change in stability. The CX1 also measured acceleration data to capture any indications of potential fractures within the concrete piers.

The Result

Within just the first week of operation, SENSR technology identified deterioration and frozen bearings that were delivering forces to bridge piers. By assessing the inclination of the piers as a function of temperature fluctuations, HNTB saw a one-inch, back-and-forth motion in the piers that confirmed the unsafe conditions of the bridge caused by those frozen bearings. During the building of a new bridge, CX1 devices ensured that construction efforts didn’t undermine the stability of the old bridge that could make a dangerous situation even worse.