WESTBANK EXPRESSWAY INSTRUMENTATION AND LOAD TESTING
The Westbank Expressway is a six-lane freeway extending from Westwood Drive in Marrero, Louisiana, to the Crescent City Connection Bridge across the Mississippi River in New Orleans, Louisiana. The primary purpose of the proposed ramp project is to complete the MacArthur Interchange and reduce the distance between successive westbound off-ramps and eastbound on-ramps by providing access ramps from the service roads to the elevated expressway. Along this six-mile portion of the expressway, damage has been documented to the existing structure, especially the inverted-T pier caps, in both the eastbound and westbound directions.
SDR was selected by LADOTD to perform the following tasks:
- Perform detailed investigation of reinforced concrete caps and girder seat bearings.
- Perform finite element analysis and stress analysis of the inverted T caps.
- Perform instrumentation and load testing of representative caps.
- Present repair recommendations.
In the load testing stage of this project, one expansion end and one fixed end of representative caps were chosen for monitoring. During the load testing process, linear variable differential transformers (LVDTs) and strain gauges were used to measure the crack opening and strains in the proximity of damaged and undamaged areas under truck loads.
As a result of load testing and numerical simulations, it was concluded that exterior girder hanger bars were deficient; therefore, strengthening recommendations using CFRP wraps, bars or post-tensioning bars were presented. It was also concluded that cracks in the inverted T caps did not affect their structural performance, but they should be sealed for durability purposes.