Key Issues and Budget Constraints with Replacing Rural, Low Traffic Volume Bridges.

Transcription

1 Key Issues and Budget Constraints with Replacing Rural, Low Traffic Volume Bridges. Case Study: Steel I-Beam Bridge Replacements using Glued Laminated Timber By Patrick Bigg, General Manager of

2 Introduction Personal History Graduated, B. Eng (civil) August 2014 (University of Tasmania) Local Government, Graduate Engineer, Huon Valley Council 2015 WRD Cert 1 Timber Structures Course July 2015 Joined WRD in Jan, 2016 First 3 months working with Senior Engineers in Jefferson, Oregon USA. Back to Australia to work under Management designing bridges, tender specs, project management and site engineering. Joined TRS in Jan, 2018 Managing general operations of the company and projects

3 Table of Contents Case Study: Steel I-Beam Bridge Replacements using GLT 1. Site Inspection, Design, Prefabrication and Transportation 2a. Prefabricated Construction ready for Single Lift Installation Seres Road Bridge and Koombooloo Creek Bridge Cowley Creek Rd Bridge 2b. Stick Built Construction South Ramleh Road Bridge and King Road Bridge 3. Versatility: Discussion about the McFadden Rd Bridge Bypass using King Rd abutments and Francis Rd Bridge s Super and Deck 4. Key Issues & Budget Constraints associated with Rural, Low Traffic Volume Bridge Replacements

4 Site Inspections Koombooloo Creek Bridge South Ramleh Road Bridge Cowley Creek Road Bridge Seres Road Bridge King Road Bridge

5 Design Design Criteria 44T Loading 100 Year Design Life 50mm +/- elevation change Reuse existing substructure where possible

6 Design Seres Road Bridge Design Specs: 14.3m Single Lane Single Span 6 Girder hog belly design 273x724mm GLT Girders 16T total weight Koombooloo Creek Bridge Design Specs: 10.5m Single Lane Single Span 4 Girder hog belly design with FiRP reinforcement 171x724mm GLT Girders 8T total weight

7 Design South Ramleh Road Bridge Design Specs: 12.2m Single Lane Single Span 5 Girder stitched hog belly design 222x762mm stitched GLT exterior girder w. 222x686mm centre girder 10T total weight King Road Bridge Design Specs: 12.5m Single Lane Single Span 4 Girder design with FiRP reinforcement 273x648mm GLT Girders 11T total weight

8 Design Cowley Creek Road Bridge Design Specs: 16.7m Dual Lane Single Span 6 Girder hog belly design Girder 1 &6: 222x1295mm Girder 2 &5: 222x1254mm Girder 3 &4: 222x1067mm Dual Lane 130mm GLT Deck Crash Proof Timber Guardrail 35T total weight

9 Prefabrication and Test Fit Jefferson, Oregon USA

10 Glulam delivery to Australia

11 Trail Layout and Transportation to Site

12 Prefabricated Construction for Single Lift Installation Seres Road Koombooloo Creek Delaminating Flanges that peel away at the touch < 20 year old

13 Fabrication Sites Prefabricated Construction for Single Lift Installation Seres Road Koombooloo Creek

14 Fabrication Sites Prefabricated Construction for Single Lift Installation Seres Road Koombooloo Creek

15 Prefabricated Construction for Single Lift Installation Demolition and Installation Seres Road Koombooloo Creek

16 Cowley Creek Rd Bridge Prefabricated Construction for Single Lift Installation

17 Stick Build Construction South Ramleh Road King Road Bridge Delaminating Flanges in the I-Beams Vertically Spiked Deck Cavitated girders and buried girder ends Fruiting Bodies Present

18 Road Closure Detours Stick Build Construction South Ramleh Road King Road Bridge

19 Stick Build Construction Demolition and Installation King Road Bridge South Ramleh Road

20 Versatility of Glued Laminated Timber Before After McFadden Bridge McFadden Bypass Approach and Substructure McFadden Bypass Bridge Francis Rd Bridge Superstructure and Deck King Rd Substructure Francis Rd Bridge and King Rd Abutments

21 Key Issues and Budget Constraints 1. Back road rural bridges often lack the maintenance regimen for the environment they are in. 2. The poor condition offers a lower level of service to the community 3. No alternative access/lengthy detours are all that s available which is expensive or environmentally disturbing should a bypass be required. 4. Lack of knowledge of how to service and maintain these bridges. If rust becomes prevalent, sandblasting and repainting/galvanising becomes a significant cost. 5. Dealing with the different bridge expectations 6. Minimise mistakes from a design and/or construction aspect. 7. Ensure all bridge components are accounted for prior to sending the bridge to site. 8. Environmental issues with heavy excavations. Having the ability to reuse the substructure reduces the amount of site disturbance and level of disruption to the surrounding environment as well as saves costs.

22 Key Issues and Budget Constraints 9. The cost on a per rate payer basis is often expensive due to the amount of people the bridge services. 10. In some cases, a bridge that is put out of service immediately, due to a L3 report or failure, may not have the funds available for quick repair. 11. Complete replacement bridges, inclusive of a new substructure, writes off any residual current value the structure holds. Reusing the substructure or repairing elements in kind saves this residual current value.

23 In Closing Steel I-Beam structures in high humidity, acidic and salty environments require significantly more maintenance than what was once thought. TRS and CCRC work together to assemble and install GLT structures within a timeframe that minimises road closures, reuses what s good in the existing structure, provides cost savings and protects the environment.

24 THANKS FOR COMING. Acknowledgements: