Monitoring of the Response of the Sagamore Parkway Bridge and its Foundations During a Live Load Test

In this paper, we report the results of a live load test performed on the Sagamore Parkway bridge over the Wabash River, Indiana. The seven-span concrete bridge was constructed from 2016 to 2018 to replace the old, east-bound bridge. The main goals of the live load test were: (i) to study the transfer of the live loads from the bridge pier to the foundation elements and the distribution of live loads among the individual piles supporting the bridge pier; and (ii) to verify the assumptions (e.g., regarding the pile cap resistance) made in bridge foundation design. For these purposes, one of the interior piers (Pier 7) of the bridge and the fifteen pipe piles supporting it were instrumented with vibrating-wire strain gauges. With the bridge temporarily closed to traffic, the live load test was performed by parking twelve loaded triaxle trucks at specific locations on the bridge deck near Pier 7 in March 2019. The truck loads were applied in seven stages, simulating the driving of several trucks over the bridge pier. The settlement of the pier was measured using a digital level during the live load test. The data from the strain gauge readings were processed to produce the history of load distribution within the cross section of the pier and among the piles in the pile group during the seven stages of the live load test. The soil in contact with the pile cap carried about half of the total live load.

Live-Load Test Results of Missouri’s First High-Performance Concrete Superstructure Bridge

For its significant economical savings and greater design flexibility, high-performance concrete (HPC) is becoming more widely used in highway bridge structures. High-performance bridges with HPC and large-diameter prestressed strands are becoming attractive to designers. Bridge A6130 is the first fully HPC superstructure bridge in Missouri. The bridge has HPC cast-in-place deck and high-strength concrete girders reinforced with 15.2-mm (0.6-in.) diameter strands. The bridge was instrumented with embedded strain gauges and thermocouples to monitor the early-age and later-age behavior of the structures from construction through service. To investigate the overall behavior of the bridge under live load, a static live-load test was developed and carried out. During the live-load test, 64 embedded vibrating wire strain gauges and 14 embedded electrical-resistance strain gauges were used to acquire the changing strain rate in the bridge caused by the varying live-load conditions. Girder deflections and rotations were also recorded with external sensors and a data acquisition system. Based on the test results, the load distribution to the girders was studied. The AASHTO specifications live-load distribution factor recommended for design was compared with the measured value and found to be overly conservative. The AASHTO load and resistance factor design live-load distribution factors recommended for design were found to be comparable to measured values. Two finite element models were developed with ANSYS and compared with measured values to investigate the continuity level of the Missouri Department of Transportation interior bent detail.