Schuyler Heim Bridge Deck Instrumentation
The 55-year-old Schuyler Heim Bridge is the largest vertical lift bridge on the west coast. The bridge is located in the Port of Los Angeles and serves as a critical traffic link for local commerce between the city of Long Beach and Terminal Island. The traffic on the bridge is mostly heavy trucks carrying cargo containers to and from the shipping ports. Because of the heavy loads, the existing deck of welded-steel grating has been in continuous distress, despite a complete replacement in 1997.
CALTRANS selected the Schuyler Heim Bridge as an experimental project to evaluate the performance of fiber reinforced polymer (FRP) deck panels to replace existing metal deck grating. To evaluate the benefits of replacing the entire metal deck with FRP, CALTRANS arranged for eight panels to be replaced, instrumented, and monitored to provide a load and stress history.
The first instrumented panels were fabricated at ACME Fiberglass in Hayward, Calif. CTLGroup was onsite during the process to install strain gages and thermocouples within the layers of the FRP. During installation of the replacement deck panels, CTLGroup installed displacement transducers, thermocouples, strain gages, environmental sensors, and, traffic counters.
The data logger system is designed to monitor data continuously, even while the bridge is fully raised. The data logger, mounted on the lift portion of the bridge, communicates through a wireless link to the bridge tender's office. CTLGroup remotely accesses the system through a dial-up connection at the tender's office. Each month, CTLGroup performs a remote static load test of the bridge, providing direction to onsite CALTRANS staff while monitoring real-time data from CTLGroup's Chicago office.