Project Details
19-JV-11111133-038
07/11/19
09/30/22
USDA Forest Products Laboratory
Researchers
About the research
This research needs project is to perform a national study on the national needs for research in timber usage in transportation. The goal of this project is to set the national agenda for the next five years.
Project Details
19-JV-11111133-044
06/13/19
12/31/23
USDA Forest Products Laboratory
Researchers
About the research
The use of cross-laminated-timber (CLT) has gained popularity over the past decade, with many advances stemming from completed research and construction projects located in Europe. In particular, CLT has been utilized in vertical construction projects where many of its inherent features have been maximized. To name a few, CLT is prefabricated, relatively lightweight, dimensionally stable, and environmentally sustainable. Despite these advances, the use of CLT in bridge structures has been limited and the adoption of CLT into governing design codes has been slow-going.
CLT shows promise as a complimentary or alternative construction material in bridge decks. Additional research would benefit the characterization of these decks to further guide the appropriate use in bridge projects. This study plan provides the steps intended to characterize the structural characteristics of CLT bridge decks subjected to typical traffic loads.
The objective of this project is to conduct a laboratory investigation of the feasibility of CLT as a primary structural material for highway bridge applications. CLT bridge deck performance will be compared with equivalent glulam bridge systems based both on a strength and serviceability basis.
Project Details
12/31/11
07/31/19
USDA Forest Products Laboratory
Researchers
Travis Hosteng
About the research
Nationwide, bridges are deteriorating at a rate faster than they can be rehabilitated and maintained. This has resulted in a search for new methods to rehabilitate, repair, manage, and construct bridges. As a result, structural health monitoring and smart structure concepts have emerged to help improve bridge management. In the case of timber bridges, however, a limited amount of research as been conducted on long-term structural health monitoring solutions, and this is especially true in regards to historic covered timber bridges. To date, evaluation efforts of timber bridges have focused primarily on visual inspection data to determine the structural integrity of timber structures.
To fill this research need and help improve timber bridge inspection and management strategies, a 5-year research plan to develop a smart timber bridge structure was undertaken. The overall goal of the 5-year plan was to develop a turnkey system to analyze, monitor, and report on the performance and condition of timber bridges. This report outlines one phase of the 5-year research plan and focuses on developing and attaching moisture sensors onto timber bridge components. The goal was to investigate the potential for sensor technologies to reliably monitor the in situ moisture content of the timber members in historic covered bridges, especially those recently rehabilitated with glulam materials. The timber-specific moisture sensors detailed in this report and the data collected from them will assist in advancing the smart timber bridge.
Project Details
06/15/18
06/30/20
USDA Forest Products Laboratory
Researchers
Travis Hosteng
About the research
Project Details
Michigan Technological University
USDA Forest Products Laboratory
Researchers
Mark Rudnicki
Robert J. Ross
About the research
Wood is highly variable because of genetic variation and variable growing environments. To make the best, highest use of our forest resources, we need to have technologies that help us assess the quality of a particu- lar tree, log, or primary product. We can then use it for its best use—nondestructive evaluation technologies enable us to characterize important properties of wood, allowing us to use it appropriately. The USDA Forest Service Forest Products Laboratory, in cooperation with organizations from around the world, develops nondestructive evaluation technologies as part of itsprogram to find the best uses for our timber resources.
The objective of this program is to develop nondestructive evaluation technologies for a range of forest materials and products, with a focus on developing technologies for assessing woody biomass from our Eastern forests.
Project Details
2012-05
01/01/14
07/31/14
USDA Forest Products Laboratory
Researchers
About the research
In seasonal frost areas, some state departments of transportation (DOTs) take advantage of the period of higher strength in midwinter by using winter weight premiums (WWPs) to increase the allowable weight that trucks can haul. Conversely, to reduce damage during the spring thaw, many road management agencies apply spring load restrictions (SLRs). The objective of this effort was to provide an understanding of the reliability, benefits, costs, and risks of alternate approaches to scheduling seasonal load restrictions on roadways.
Project Details
05/22/15
01/31/19
USDA Forest Products Laboratory
Researchers
Travis Hosteng
About the research
Investigation of Glulam Girder Bridges with Composite Prefabricated Decks
Researchers
Travis Hosteng
About the research
Researchers
Travis Hosteng
James Wacker
About the research
Background
Most engineering analyses of historic covered timber bridge trusses are based solely on routine site inspections. In addition, assumptions about the behavior of connections and support conditions are made during the systemic analysis stage. This approach can lead to inaccurate and, in most cases, overly conservative load-capacity ratings for these historic structures.
By conducting live-load testing to assess the overall performance of the superstructure system, engineers will be able to perform structural analyses in a more reliable fashion. The measured live load response should also provide a measure of the effectiveness of various structure modeling techniques. The end result should be a more reliable approach to assigning safe load-capacity ratings for historic covered bridges.
During Phase I of this project, 11 covered bridges were evaluated by live-load testing methods: three covered bridges in Parke County, Indiana, built of variations of the Burr-Arch truss configuration; four other covered bridges in Indiana built of variations of the Howe truss configuration; and four covered bridges in Vermont built of variations of the Queen post truss configuration.
Objective
This study will continue the work initiated in Phase I to develop and establish recommended procedures for safely and reliably load-rating historic covered bridges through physical testing.
Approach
- Develop field protocols for live-load testing of historic covered bridges, in conjunction with analytical modeling data requirements
- Conduct live-load testing on several bridges representing the main truss types that have been preserved
- Analyze load-testing field data and disseminate data to analytical modeling efforts
- Develop a rationale for incorporating physical test data into existing load-rating procedures
- Prepare a comprehensive guidance manual that documents recommended procedures for live-load testing and enhanced load rating of historic covered bridges
Researchers
Travis Hosteng
About the research
The purpose of the project is to develop automated techniques for determining vehicle characteristics as they cross the smart timber bridge. By determining vehicle characteristics–such as vehicle weight, axle weights, axle spacings, travel lane, speed, and so forth–it will be possible to enhance other algorithms for predicting usage and induced damage or deterioration.
Two different vehicle characterization approaches will be investigated:
- Use of conventional instrumentation
- Use of non-conventional instrumentation including the sensing skin