Evaluation/ Modification of IDOT Foundation Piling Design and Construction Policy

Long, James; Hendrix, Joshua; Baratta, Alma

Permalink

https://hdl.handle.net/2142/13791 Copy

Description

Title

Evaluation/ Modification of IDOT Foundation Piling Design and Construction Policy

Author(s)

Long, James; Hendrix, Joshua; Baratta, Alma

Issue Date

2009-03

Keyword(s)

• piles
• LRFD
• pile capacity
• bearing capacity

Abstract

The Illinois Department of Transportation (IDOT) estimates pile lengths based on a static analysis method; however, the final length of the pile is determined with a dynamic formula based on the pile driving resistance exhibited in the field. Because different methods are used for estimating and for acceptance, there is usually a lack of agreement between the estimated length and the driven length of pile. The objective of this study is to assess the ability of the methods currently used by IDOT, to assess other methods for estimating pile capacity, to improve the methods if possible, and to determine resistance factors appropriate for the methods. This study reports pile load test data along with pile driving information and subsurface information, and uses this information to investigate and quantify the accuracy and precision with which five different static methods and five different dynamic formulae predict capacity. These static methods are the IDOT Static method, the Kinematic IDOT (K-IDOT) method, the Imperial College Pile (ICP) method, Olson’s method and Driven. The dynamic formulae are the EN-IDOT formula, the FHWA-Gates Formula, the Washington State Department of Transportation (WSDOT) formula, the FHWA-UI formula, and WEAP. Three databases were assembled and used to quantify the ability of these methods to predict capacity. Results suggest that the three dynamic formulae: WS-DOT, the FHWA-Gates, and the UI-Gates provide similar accuracy. However, the WS-DOT formula is simple to implement and predicts capacity most consistently for the databases reviewed in this study. A value of 0.55 is recommended for the resistance factor for redundant piling.

Publisher

Illinois Center for Transportation (ICT)

Series/Report Name or Number

FHWA-ICT-09-037

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/13791

Sponsor(s)/Grant Number(s)

ICT-R27-24

Owning Collections