Comparison of Static Lateral Behavior of Vertical and Battered Pile Groups of the I-10 Twin Span Bridge Using Finite Element Simulation-Paper

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The study compares the static lateral behavior of vertical and battered pile groups using three-dimensional finite element (FE) simulations. The battered-pile model was validated against a full-scale lateral load test of the 24-pile M19 pier foundation of Louisiana’s I-10 Twin Span Bridge. A vertical-pile model was then created by changing the pile inclinations. The simulations included nonlinear soil and concrete behavior and pile–soil contact effects.<br /><br />At comparable lateral loads, the battered group showed substantially greater lateral resistance, with pile-cap displacement about 60–70% lower than for the vertical group. The distribution of lateral load among pile rows also differed: the leading row carried the largest share in the vertical group (31%), whereas the two middle rows carried the largest shares in the battered group (31% and 28%). Axial loads followed a similar shift, being greatest in the leading and trailing rows for vertical piles and in the middle rows for battered piles.<br /><br />Despite the battered group’s higher overall lateral capacity, it mobilized less soil resistance. The vertical group had 58% greater mobilized front-face soil resistance and a deeper zone of influence. The authors attribute the battered piles’ improved performance to their inclination and the resulting additional axial resistance, rather than to greater soil resistance.<br /><br />The findings demonstrate that pile inclination affects group stiffness, load sharing, axial forces, and soil response. The validated FE approach offers a practical means of investigating pile-group behavior, though the conclusions are based on the modeled foundation and soil conditions.

Keywords

pile groups

battered piles

vertical piles

lateral resistance

finite element simulation

pile-soil interaction

bridge foundation

load distribution

axial forces

soil resistance