Lateral Loading of Battered Piles With Respect to Footing Size

Open Access
- Author:
- DeRosa, Vincent John
- Area of Honors:
- Civil Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Jeffrey A Laman, Thesis Supervisor
Jeffrey A Laman, Thesis Supervisor
Patrick Reed, Thesis Honors Advisor - Keywords:
- battered piles
load ratio - Abstract:
- The Pennsylvania Department of Transportation’s current policy restricts the lateral loading of battered piles to a 3.5 to 1 vertical to horizontal load ratio. Accompanying this is the assumption that all lateral force is resisted by battered piles and conversely, none of the lateral force is resisted by vertical piles. These two decisions result in the need for additional piles and increased footing sizes, creating large total foundations. The purpose of this study is to analyze these two specifications in an attempt to reduce the required foundation size. Traditional Euler beam theory is studied to determine the behavior of battered and plumb piles, but is complicated due to nonlinear soil-pile interaction. As a result, the p-y method for relating pile deflection to soil resistance was used to predict pile behavior under the influence of varying load ratios in three different types of soils. Because the p-y method is an iterative process, the computer program Lpile was utilized to create the different curves based on individual soil and pile properties. The curves were then used to develop multi-linear spring constants that can effectively represent the soil in a structural analysis model. Piles at three different batters in three types of soil were analyzed under varying load ratios to determine the effects on pile deflection and bending moment. The results indicate that pile behavior is governed by the beam-column interaction equation and suggests that the actual lateral loads acting on the pile play a much more significant role in pile behavior than load ratios. In addition, results indicate that PennDOT’s assumption that all lateral force is resisted by battered piles is extremely conservative and plumb piles are shown to have significant lateral resistance.