IN-SITU TESTS OF THREE BENTS AT SOUTH TEMPLE BRIDGE ON INTERSTATE 15

The present report describes the test procedures and results of three in-situ full-scale tests carried out in Salt Lake City, Utah in 2000. The tests were carried out on the southbound lanes of the South Temple Bridge at Interstate 15, in Salt Lake City. The first test was carried out on a three-column bridge bent without the road deck (Bent #4S), the second test was carried out on an identical three-column bridge with half the gravity load present from the deck (Bent #5S), and the third test was carried out on Bent #6S, with half the gravity load from the deck, which was seismically retrofitted with carbon fiber reinforced polymer (CFRP) composites. For all three bents, the foundation was retrofitted through a reinforced concrete grade beam overlay and through pinning of the pile caps to the piles. The report provides detailed information on the test setup, the loading scheme used to simulate seismic loads, a description of the condition of the as-is bridge bents, the design of the CFRP composite for seismic retrofit of Bridge Bent #6S, and an assessment of the performance of the three bridge bents. It was found that the grade beam improved the simulated seismic performance of all three bents. For Bent #6S, which had the CFRP composite seismic retrofit in addition to the grade beam, the seismic retrofit goal of increasing the displacement ductility of the bridge by a factor of two was achieved.