Lateral Resistance of Abutment Piles Near Mechanically Stabilized Earth Walls

Pile foundations for bridges must often resist lateral loads produced by earthquakes and thermal variation. Because of the lack of large scale tests, there is almost no guidance for engineers in assessing the lateral resistance of piles located close to these MSE walls. The objective of this study was to assess lateral pile resistance as a function of distance from the wall face and predict force induced in the reinforcements. Full-scale lateral load tests were conducted on 24 piles located at 2, 3, 4, and 5 pile diameters behind 4.6 and 6-m high MSE walls. P-multipliers were developed to account for the decrease in lateral soil resistance. Little reduction occurred for piles located more than about 4 pile diameters from the wall. Measured tensile forces in the MSE reinforcements increased as the load on the pile increased and decreased rapidly with transverse distance from the direction of loading. Multiple linear regression equations were developed to predict maximum tensile force induced in reinforcing elements by lateral loading.