Kentucky Lake Pipe Pile Load Test Program

Abstract

A design-phase pile load test program has been performed to study the constructability and design parameters for large-diameter steel pipe piles for the proposed Kentucky Lake Bridge as part of the US68/KY 80 Bridge over Kentucky Lake project in Marshall and Trigg Counties, Kentucky. The pile load test program included a 26.7-MN (6000-kip) static axial pile load test, 26.7- and 37.8-MN (6000- and 8500-kip) axial pseudo-static pile load tests, a 1.87 MN (420-kip) lateral pseudo-static pile load test and dynamic pile testing on six large-diameter pipe piles in difficult soil conditions. The pile load test program confirmed that the proposed 1.22- and 1.83-meter-diameter (48- and 72-inch-diameter) steel pipe piles with wall thicknesses ranging from 25 to 51 mm (1 to 2 in.) could be installed to the anticipated target nominal resistances and respective elevations at the site using a Menck MHU800S hydraulic hammer. The pile load test program indicated that the proposed steel constrictor plates should be installed within the pipe piles to increase bearing resistance, and helped the design team to gather information regarding viable design of the constrictor plates, how to locate the constrictor plates relative to the pile tip location, and in what soil strata the constrictor plates should bear within to mobilize additional bearing resistance in the pile design. Axial static and pseudo-static pile load testing indicated that the skin resistance values used in the pile design phase were valid and likely somewhat conservative and indicated that the 1.22-meter-diameter (48-inch-diameter) piles were more likely to achieve a plugged condition.