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Bridge Deterioration Quantification Protocol Using UAV

https://research.thinkwood.com/en/permalink/catalogue1966
Year of Publication
2018
Topic
Serviceability
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Author
Duque, Luis
Seo, Junwon
Wacker, James
Publisher
American Society of Civil Engineers
Year of Publication
2018
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Bridges and Spans
Topic
Serviceability
Keywords
Bridge
Unmanned Aerial Vehicle
UAV
Photogrammetry
Damage
Field Measurements
Pixel
Research Status
Complete
Series
Journal of Bridge Engineering
Summary
This paper focuses on evaluating the effectiveness of an unmanned aerial vehicle (UAV) as a supplementary bridge damage quantification tool. For this study, a glued-laminated timber arch bridge in South Dakota was selected, and an UAV was utilized for the bridge damage quantification. A recommended four-stage UAV-enabled bridge damage quantification protocol involving image quality assessment and image-based damage quantification was developed. A field application using the UAV to measure crack lengths, thicknesses, and rust stain areas of the selected bridge was conducted following the recommended protocol. The image quality parameters, including sharpness and entropy, were used to determine the quality of the UAV-captured images. Pixel- and photogrammetry-based measurements using the high-quality images were obtained to quantify the bridge damage, and the damage was compared to that from actual field measurements. Once the damage information was gathered, the UAV image–based damage level classification was established based on the damage levels defined by current standards. The findings confirmed the accuracy of the recommended protocol, with results within 3.5, 7.9, and 14.9% difference for crack length, thickness, and rust stain area, respectively, when compared with the field measurements.
Online Access
Free
Resource Link
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Highly Efficient Strengthening of Local Load Introduction Areas of Engineering Wood Structures Using Polymer Concrete Grouting

https://research.thinkwood.com/en/permalink/catalogue691
Year of Publication
2014
Topic
Design and Systems
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Author
Hädicke, Wolfram
Kaestner, Martin
Rautenstrauch, Karl
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Topic
Design and Systems
Mechanical Properties
Keywords
Photogrammetry
polymer concrete
Reinforcement
Self-Tapping Screws
Load Carrying Capacity
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
The development of wide-span structures occurs high reaction forces at the bearings. The load-bearing capacity is strongly limited, because of the low compression strength and stiffness of wood perpendicular to the grain. One common possibility of strengthening the support is the application of self-tapping screws [1],[2]. Subject of the presented research project is the study of a new, practicable and quite easy to manage type of reinforcement for load transfer areas. To increase the load carrying capacity drill holes and block shaped areas filled with polymer concrete are inserted into the timber. Due to the rigid bond between wood and polymer concrete as well as a geometrical adaption to the stress distribution, it is possible to increase the load carrying capacity and the compressive stiffness significantly compared to conventional reinforcement by self-tapping screws. First inchoate versions of bearing reinforcement have been designed and used very successfully as part of another research project to increase the bending capacity of glulam beams by hybrid material composites [3],[4]. Figure 1 shows one example of the tested designs. The diagram in Figure 2 illustrates the increase of the transversal load bearing capacity compared to FE-simulation of the same member without reinforcement.
Online Access
Free
Resource Link
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