Colemans Bridge Strengthening and Maintenance Review of Environmental Factors Roads and Maritime Services | June 2019
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Colemans Bridge Strengthening and Maintenance Review of Environmental Factors Roads and Maritime Services | June 2019 BLANK PAGE Colemans Bridge Strengthening and Maintenance Review of Environmental Factors Roads and Maritime Services | June 2019 Prepared by GeoLINK and Roads and Maritime Services RMS. 19.1275 ISBN: 978-1-925891-51-5 Copyright: The concepts and information contained in this document are the property of NSW Roads and Maritim e Services. Use or copyi ng of this document in whol e or in part without the written permission of NSW Roads and Maritime Services constitutes an infringement of copyright. Document controls Approval and authorisation Title Colemans Bridge Strengthening and Maintenance review of environmental factors Accepted on behalf of NSW Michael Youngberry Roads and Maritime Services by: Project Manager Signed: Dated: 28 June 2019 Document status Document status Date Prepared by Reviewed by Draft 1 25/03/19 David Havilah Jacob Sickinger Draft 2 24/05/19 David Havilah RMS Version 3 18/06/2019 David Havilah RMS Version 4 28/06/2019 David Havilah RMS Executive summary The proposal Roads and Maritime Services (Roads and Maritime) proposes to undertake bridge truss strengthening and maintenance on Colemans Bridge (B2594), on Union Street (MR544) over Leycester Creek, Lismore within Lismore City Council Local Government Area. Colemans Bridge spans over Leycester Creek, approximately 70 metres north-west of Wilsons River. The Leycester Creek and Wilson’s River sub- catchment forms part of the larger Richmond River catchment of northern NSW and drains to the sea at Ballina. The work is required to improve the structural capacity of the bridge in order to keep Colemans Bridge serviceable. Colemans Bridge is a critical link in the road infrastructure of the Lismore area. It is approached by Union Street (to the south-west) and Bridge Street (to the north) and in combination with Fawcett Bridge, provides an important link between the Lismore Central Business District (CBD) and South Lismore (as well as allied townships and farmland to the south and west). Colemans Bridge is listed as a heritage item of State significance on the State Heritage Register. Accordingly, application will be made to the NSW Heritage Office for a Section 57(2) exemption to facilitate the Project prior to works on bridge. The proposal will include the following aspects: • Establishment of a site compound on the north-eastern side of the bridge (same site compound to be used for Fawcett Bridge maintenance). The site compound will be used for site facilities (site offices and amenities) and materials storage • Construction activities are required above and below the deck and on the embankment eight metres either side of the bridge. Construction works are not required within the water however access to the underside of the bridge may be required via the water with the use of a barge and elevated work platform. If required access for this work would be undertaken from a public boat ramp near Ballina Street Bridge. • Construction activities above the deck include: - Re-stressing of the stress laminated timber (SLT) deck - Strengthening of the top chord of the dare trusses with new truss lateral sway brace - Replacement of the existing traffic barrier - Replacement of the bridge wearing course - Minor footway repairs - Repainting of the bridge truss with hand tools to restore the appropriate heritage bridge colour scheme (steel elements black, timber elements white). - Minor localised painting of the bridge in appropriate bridge heritage colours. Localised painting for repairs to the steel bottom chords will remain grey. • Construction activities below the deck include: - Localised steel bottom chord corrosion repairs and repaint - Timber trestle pier repairs • Minor vegetation clearing within eight metres of the bridge will be required to facilitate works around timber trestle piers • Minor earthworks will be required to provide access to timber trestle piers and below deck work areas • Elevated (hung) scaffolding will be required to conduct work for the SLT deck re-stressing and localised repairs to the steel bottom chord and girders. Weather permitting, construction is expected to start in late 2019 and will take approximately eight months to complete, weather permitting. To minimise the period of disruption to the public, the bridge would be closed to traffic on some weekends during the extent of the project and occasionally on the Monday following weekend closures. At all times during closures alternate detours would be available in the order of Colemans Bridge upgrade i Review of Environmental Factors between 2.8 km and 3.7 km, depending on the route taken, origin and destination. During the project pedestrian access on one side of the bridge would be maintained at all times. Need for the proposal Colemans Bridge is one of 26 bridges identified for conservation in the Roads and Maritime Services Timber Truss Bridge Conservation Strategy, which was developed in consultation with the Heritage Council of NSW. The strategy was developed to address the long-term management of these structures and aims to establish a balance between infrastructure provision and heritage conservation. Given its heritage value, Colemans Bridge was identified to be retained and upgraded to meet the current vehicle load standards while preserving its heritage features. The NSW Government is funding the Colemans Bridge upgrade as part of its $145 million-dollar Bridges for the Bush commitment to improve road freight productivity in regional NSW by replacing and upgrading bridges resulting in fewer bridge closures. Colemans Bridge is a critical link in the road infrastructure of the Lismore area. It is approached by Union Street (to the south-west) and Bridge Street (to the north) and in combination with Fawcett Bridge, provides an important link between the Lismore CBD and South Lismore (as well as allied townships and farmland to the south and west). It is important to Roads and Maritime that the bridge remains in a serviceable condition at all times. Appraisal of the bridge by Roads and Maritime has found it requires maintenance and strengthening to improve safety, amenity, capacity and longevity in the short to medium term. The required work includes: • Strengthening the Dare-type trusses • Upgrading the extant crash barrier (thrie beam) which is in poor condition • Repairing and resealing the extant SLT decking which is damaged and uneven • Repairing modern crash barriers and fencing on the bridge approaches • Replacing a trestle post on one timber pier on the western bank • Repainting the bridge. The timber truss will be painted with; timber elements in a white colour scheme and steel elements in a black colour scheme. Localised painting for repairs to the steel bottom chords will remain grey. Previous painting on the bridge involved the removal of lead paint, therefore there is no lead paint removal required as part of this proposal. The proposal is required to: • Ensure Colemans Bridge remains serviceable and complies with current road safety requirements • Maintain safety for road users and pedestrians • Protect the heritage values of the bridge. Proposal objectives and development criteria Strengthening and maintenance works are required on Colemans Bridge to improve safety and increase the service life of the bridge whilst retaining its heritage value. The objectives of the proposal are to: • Improve the structural capacity of the bridge through strengthening • To support bridge longevity and maintain a safe connected road network • To reduce future maintenance. The works would be carried out in accordance with: • Australian Bridge Design Code (Standards Australia, 1996) • Australian Standard AS5100- 2017 Bridge Design • Roads and Maritime Services Technical Directions and Specifications • Roads and Maritime Timber Truss Bridge Conservation Strategy (2012a) Colemans Bridge upgrade ii Review of Environmental Factors • Roads and Maritime Services Timber Truss Bridge Overarching Conservation Management Plan (2018). Options considered The following options were considered for the proposal: Option 1: Do nothing This option involves not undertaking any maintenance work and would lead to further deterioration of the bridge. The ‘do nothing’ option therefore does not meet the objectives of the brief or Roads and Maritime Timber Truss Bridge Conservation Strategy and the New South Wales Government’s Bridges for the Bush program. Option 2: Proposal with full bridge closure This option involves maintenance works on the bridge being undertaken as proposed under full bridge closure which would allow the project to be completed in four months. Option 3: Proposal with some weekend and occasional Monday closures This option involves maintenance works on the bridge being undertaken as proposed with the bridge closed to traffic on some weekends during the extent of the project. There may also be odd occasions where the bridge will need to be closed on Mondays following the weekend closures. This option would allow the project to be completed in approximately eight months. Option 3 - Proposal with some weekend and occasional Monday closures - is the recommended option to meet the proposal objectives whilst aiming to minimise impacts of the project on local residents, businesses and motorists by reducing bridge closures on Mondays - Fridays. The number of weekend closures would be up to 20 over the duration of the project. This option allows heritage values to be retained