Prediction of timber bridge girder strength and stiffness using stress wave analysis

Salonen, Marcus (2015) Prediction of timber bridge girder strength and stiffness using stress wave analysis. [USQ Project]


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Australia currently has in service over 33,500 timber road bridges owned primarily by state and local government authorities. On average, most of these timber bridges have been in service for around 50 years and are in a structural weakened condition due to increasing traffic loads, construction methods, maintenance practices and environmental locations. Maintenance and routine inspections are required on all bridge structures in Australia. Most timber bridges are a major issue for most engineers in state and local governments because timber bridges are built from organic material, and it is difficult to identify the failure modes and the current level of deterioration within the timber structure itself. To address this issue this project looks at an advance inspection method called Stress Wave Time (SWT).

SWT calibrated data for Australian wood species is very limited and through a destructive test of a known Australian wood species, Tasmanian Blue Gum (Eucalyptus glob- ulus), the SWT times can be calibrated for different internal voids/defects. By using this calibrated SWT times to investigate an existing timber bridge structural properties and Finite Element Analysis (FEA), this report identifies the structural strength and stiffness of existing timber girders from a bridge structure.

The study creates a baseline from the SWT values obtained in the destructive test, and then these values were applied to an existing timber bridge in the field to create a theoretical FEA model designed for structural strength and stiffness.

Deflections were calculated using Strand7 linear solver and 3 different load cases were tested on the theoretical models and compared to an existing timber girder field deflection. The results from this project confirmed that SWT values are a justifiable method of acquiring the structural strength and stiffness of timber girder in the field.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Civil Engineering project
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Manalo, Allan
Date Deposited: 31 May 2016 02:12
Last Modified: 06 Jun 2016 01:01
Uncontrolled Keywords: Timber bridge, girder strength, girder stiffness, stress wave analysis, finite element analysis
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090599 Civil Engineering not elsewhere classified
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400599 Civil engineering not elsewhere classified

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