Forensic Collapse Investigation of a Concrete Bridge with Timber Piers

Borello, Daniel J.; Andrawes, Bassem; Hajjar, Jerome F.; Olson, Scott Michael; Hansen, James; Buenker, Jason

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https://hdl.handle.net/2142/13799 Copy

Description

Title

Forensic Collapse Investigation of a Concrete Bridge with Timber Piers

Author(s)

• Borello, Daniel J.
• Andrawes, Bassem
• Hajjar, Jerome F.
• Olson, Scott Michael
• Hansen, James
• Buenker, Jason

Issue Date

2009-04

Keyword(s)

• timber piers
• bridge collapse investigation

Abstract

This report outlines the forensic investigation of the collapse of Bridge No. SN 019-5010 in DeKalb County, Illinois on August 19, 2008. The bridge consisted of three 42 feet precast prestressed concrete deck beams simply-supported by concrete pile caps with a timber pile foundation. Assessment based on site investigation, in situ readings, and analysis indicated that a geotechnical or superstructure failure may be ruled out. Samples of the oak timber piles were retrieved and tested under pure compression as well as combined compression and flexure. Laboratory testing results of these specimens were used to calibrate an analytical model of a full-scale single timber pile. The analytical model considered both symmetrical and unsymmetrical loading of the bridge. The results of the analytical model were used to determine the required live load to initiate collapse. The results of the investigation indicate that structural overload, leading to fracturing of the timber piles in combined compression and flexure, is the likely reason for the bridge failure.

Publisher

Illinois Center for Transportation (ICT)

Series/Report Name or Number

FHWA-ICT-09-042

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/13799

Sponsor(s)/Grant Number(s)

ICT-R27-SP12

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