Large Scale Laboratory Testing to Evaluate Axial Load Capacity of Sheet Piles for Bridge Abutments

This paper presents the results of a full scale, axial load test program carried out on two well instrumented steel sheet pile walls. Traditionally in the U.S., sheet piles are used in bridge abutments to defend bridge abutments against erosion and scour which is often an important design consideration for bridges located near rivers and streams. In this design approach, the axial loads from the bridge superstructure are considered to be supported primarily by deep foundations typically installed behind the scour protection sheet piles. This design approach, although practical, is usually also very conservative. In contrast, short span bridges have been reported as successfully built with steel sheet piles as the main vertical load bearing element in the bridge abutments in several European countries. Despite these reported positive case histories, the axial load contribution from abutment sheet piles is still routinely neglected in design assumptions by U.S. highway agencies. One of the main issues hindering the inclusion of any axial load capacity contribution from these elements is a scarcity of well documented full scale axial load tests on instrumented sheet piles. This paper presents experimental results of axial load tests of sheet piles carried out in a large geotechnical test pit at the Energy Production and Infrastructure Center (EPIC) at University of North Carolina at Charlotte (UNC Charlotte). These results provide experimental evidence that sheet pile elements have great potential to be used as the main axial load bearing foundation element in short span bridges.