PMSS Project Details

Project ID:	FHWA-PROJ-08-0050
Project Name:	Howe Truss Bridge Design and Performance
Status:	Active
Contact:	Last Name: Duwadi First Name: Sheila R Telephone: 202-493-3106 E-mail: sheila.duwadi@dot.gov
Organization:	Federal Highway Administration - Turner-Fairbank Highway Research Center (TFHRC)
Office:	Office of Infrastructure Research and Development
Team:	Hazard Mitigation Team
Roadmap/Focus area(s):	Historic Preservation Infrastructure Research and Technology Strategic Plan and Roadmap
Project Description:	For a long time, there has been interest in how William Howe built his original Howe Trusses, which had iron verticals. An interesting aspect is that his original design permitted tightening of the metal verticals by turning the nuts to induce compression in the diagonals and tension in the chords. Colonel Long earlier used wedges in the joints of his patented trusses to modify the stresses in the diagonals, verticals, and chords. This research would study the design and performance of Howe truss bridges. A classic Howe truss in relatively decent condition could be selected and then shored, the verticals loosened, instrumentation installed, and the nuts tightened to change the stress levels in the members, the shoring removed, and live loads applied. Data could be gathered throughout this process and a time history of member forces and displacements. The data would be useful in calibrating viscoelastic models for the Howe truss. The final report would provide understandable, practical information on behavior, modeling, and design for Howe truss bridges. The results could have application to many of the 140 Howe trusses in existence, and could also be used in designing new covered bridges.
Laboratories:	Not Applicable
Start Date:	October 1, 2008
End Date:	September 30, 2013
Funding Amount:	$212,500.00
FHWA Program Name:	National Historic Covered Bridge Preservation Program
Goals:	The primary object of this project is to study in a historical context of the design, and determine the performance of Howe truss bridges.
Project Type:	Offsite
Background Information:	Data not yet available
Test Methodology:	A classic Howe truss in relatively decent condition would be selected and then shored, the verticals loosened, instrumentation installed, and the nuts tightened to change the stress levels in the members, the shoring removed, and live loads applied. Data will be gathered throughout this process and a time history of member forces and displacements will be analyzed and documented.
Other Information:	Funding of $241,500 is $204,000 from the Federal Highway Administration and $37,500 from the National Park Service.
Partners:	Data not yet available
More Information URL(s):
Fieldtest:	Data not yet available
Expected Benefits:	Data not yet available
Deliverables:	Name: Howe Trusses – Design and Performance Product Type(s): Research report, Techbrief Description: The product will be a final report providing understandable and practical information on the behavior and modeling and design of Howe truss covered bridges. Audiences: Researchers, State highway agencies, Bridge design professionals, Federal Turner-Fairbank Highway Research Center staff Secondary Audiences:
Related URL(s):
Project Findings:	Data not yet available
FHWA Topics:	Roads and Bridges--Structures
TRT Terms:	Trusses Covered Bridges Truss Bridges Infrastructure Bridges Research
FHWA Disciplines:	Design Structures
Subject Areas:	Bridges and other structures History Research