The Norwich Street Bridge

Transcription

1 The Norwich Street Bridge Class Environmental Assessment Open House May 17, :30-8 p.m. Guelph City Hall

2 Phase 1 Phase 2 Project File Our Study Process: This study is being undertaken as a Schedule B Municipal Class Environmental Assessment (EA) Two phase planning process under the Ontario EA Act Requires all reasonable alternatives to be considered Primary goal is to minimize or avoid impacts on the community and surrounding environment Phase 1: Problem/Opportunity Description of the problem and/or opportunity to be addressed by the project Phase 2: Alternative Solutions Feasible ways of solving the identified problem(s) or addressing the opportunity(ies), from which a preferred solution is selected (in other words, how can the problem be addressed?) Based on our understanding of existing and future needs of this community, the Problem / Opportunity Statement for this study is: Problem or Opportunity Alternative Solutions Document the Planning Process The City of Guelph plans to explore how to best maintain this heritage crossing while balancing social, cultural, natural environment, technical and economic responsibilities. We are here

3 Study Area About the Norwich Street Bridge: Located on Norwich Street between Cardigan Street and Arthur Street North Connecting link for the Goldie Mill Neighbourhood to the downtown core and downtown trails Steel pony truss structure built in 1882 by the Hamilton Bridge Company and converted into a pedestrian bridge in 2002 Steel and iron portions of the Norwich Street Bridge are designated under Part IV of the Ontario Heritage Act (1990)

4 Review of Public Open House #1 (September 21, 2016) What we heard from you (over 90 attendees): Bridge crossing is a vital part of the community Significant Safety concerns if users were required to use Eramosa Road bridge due to traffic volume / speed and steep approaches to the Woolwich Street intersection Enjoy the quiet atmosphere from lack of vehicles Allows for views of nearby vegetation and river Heritage designation and looks of the existing bridge are important Restoration activities are strongly preferred over complete replacement

5 Parts of the Norwich Bridge Steel Truss Superstructure: Trusses, Deck, Railings, Floor Beams, Stringers Name Plate Steel Beam Guide Rail Wood Deck Vertical Top Chord Diagonal Railing Steel Bracing Pin Connection Wood Stringer Steel Floor Beam Bottom Chord Abutment Substructure: Foundations, Abutments

6 Alternative Solutions Solution Description Photos Use modern techniques to repair Alternative 1: Restoration/ Rehabilitation deteriorated elements Reinforce bridge where required Mimic style of original design Repair substructure Maintain existing trusses as decorative feature that only Alternative 2: New Bridge Structure between Trusses supports its own weight with minor repairs Construct new, self supporting bridge between existing trusses Repair existing substructure Potentially construct new foundations behind existing abutments

7 Alternative Solutions Solution Description Photos Use modern techniques to replace Alternative 3: Replacement the bridge Mimicking style of original design Completely repair or replace existing substructure Original Structure Replacement Structure Alternative 4: Bridge Removal Permanently remove structure Not carried forward to evaluation Site of former steel truss bridge after removal Alternative 5: Do Nothing Leave as-is Not carried forward to evaluation Norwich Bridge partial collapse following heavy flood, 1948 (Guelph Mercury)

8 Evaluation of Alternatives Alternative 2 Alternative 1 Alternative 3 Factor/Criteria New Bridge Structure between Restoration / Rehabilitation Replacement Trusses Socio-Economic Longer-duration closure during Moderate-duration closure during Could require a shorter-duration Environment construction. construction. closure. Property Impacts Maintains path width on current May marginally narrow path width Extended closure would occur if Impacts to bridge. on current bridge. abutments where reconstructed. Businesses and Maintains existing bridge trusses Maintains existing bridge trusses Maintains the existing crossing as a Adjacent Land Uses with moderate restoration. with moderate restoration. connecting link between the Community Major restorations would primarily Appearance of bridge would adjacent neighbourhood and Connectivity and take place below the bridge deck, marginally change with addition of downtown. Mobility including minimizing aesthetic changes that new structure between trusses. Opportunities to widen the Cyclist/Pedestrian are visible. Maintains the existing crossing as a travelled width of the structure can Movement Greater likelihood of additional connecting link between the be explored. Visual Impacts closures in the near future for adjacent neighbourhood and Views of river and surrounding area Public Safety additional repairs to the bridge. downtown. could be enhanced as a part of the Maintains the existing crossing as a replacement. connecting link between the Look of new structure could be adjacent neighbourhood and significantly different from existing downtown. Statements in bold text are considered negative Most Preferred Least Preferred

9 Evaluation of Alternatives Alternative 2 Alternative 1 Alternative 3 Factor/Criteria New Bridge Structure between Restoration / Rehabilitation Replacement Trusses Cultural Environment Retains bridge structure elements Retains bridge structure elements Results in the removal of the Built Heritage that are deemed to have heritage that are deemed to have heritage bridge trusses that are deemed to Archaeological value. value. have heritage value. Potential Major restoration works on Moderate structural repairs to Heritage elements could be heritage elements would need to heritage elements required to salvaged for incorporation into the be reviewed to ensure they are extend life of structure. new structure or to be put on consistent with heritage style of No anticipated impacts to areas display at another location. construction. with archaeological potential. A Stage 2 Archaeological No anticipated impacts to areas Assessment would be required to with archaeological potential. extend the west bridge abutment outside of the watercourse. Statements in bold text are considered negative Most Preferred Least Preferred

10 Evaluation of Alternatives Alternative 2 Alternative 1 Alternative 3 Factor/Criteria New Bridge Structure between Restoration / Rehabilitation Replacement Trusses Natural Environment Minor clearing of vegetation in Minor clearing of vegetation in Minor clearing of vegetation in Aquatic Habitat and vicinity of structure to facilitate vicinity of structure to facilitate vicinity of structure to facilitate Fish Passage works. works. works. Vegetation No permanent changes to in-water No permanent changes to in-water No permanent changes to in-water Wildlife and Habitat footprint or changes to fish footprint or changes to fish footprint or changes to fish Species at Risk passage. passage. passage. Restored bridge may provide New structure may provide nesting New bridge may provide nesting nesting area for birds. area for birds. area for birds. Replacement of abutments, walls and footings would have short term impacts to the river. Opportunities to increase span of structure to match or exceed the width of the river. Statements in bold text are considered negative Most Preferred Least Preferred

11 Evaluation of Alternatives Alternative 2 Alternative 1 Alternative 3 Factor/Criteria New Bridge Structure between Restoration / Rehabilitation Replacement Trusses Technical Environment Scope may expand significantly Existing deck is near the end of its Coordination with Guelph Hydro Design Standards during construction, resulting in useful life. for use of a crane on site would Utilities further delays/costs. Coordination with Guelph Hydro likely be required. Constructability Salting of the bridge (if currently for use of a crane on site would Opportunities to support the Geometry on going) during winter months likely be required. adjacent utilities could be explored. will continue to deteriorate steel May only require surface repairs to New structure can be designed to elements. existing walls if new foundations current standards for pedestrian Minimal impacts to existing utilities. are used. bridge loading. Additional structure is required to Additional structure is required to support utilities south of the support utilities south of the bridge. bridge. Additional strengthening is New structure can be designed to required to meet current design current standards for pedestrian standards for pedestrian bridge bridge loading. loading. Trusses would no longer support pedestrian loads, increasing their remaining life. Statements in bold text are considered negative Most Preferred Least Preferred

12 Evaluation of Alternatives Alternative 2 Alternative 1 Alternative 3 Factor/Criteria New Bridge Structure between Restoration / Rehabilitation Replacement Trusses Economic Capital Cost = $ 580,000 Capital Cost = $ 660,000 Capital Cost = $ 1,100,000 Considerations Moderate maintenance costs Minimal maintenance costs in Largest cost in the short-term, but Capital and Life Cycle initially, would increase short-term, gradually increase over provides opportunity for Costs significantly over time. time. maximized design life. Structure Longevity Next major rehabilitation or Estimated life of new structure of Minimal maintenance costs in replacement estimated in years. short-term, gradually increase over years. Original elements may require time. repairs or replacement in next 25- Next rehabilitation estimated in years. years. CONCLUSION Alternative 2 is the most preferred alternative. Statements in bold text are considered negative Most Preferred Least Preferred

13 Existing Norwich Bridge Plan View Isometric View Cross Section

14 Preliminary Preferred Alternative 2 Proposed Foundation Plan View Isometric View Cross Section

15 Study Recommendations Following the Evaluation of Alternatives, it is recommended that Alternative 2 be carried forward to design and construction. Design should provide minimal obstruction of the existing trusses as well as of views to the Speed River and surrounding vegetation. An additional structure should be built to support the sanitary sewer and watermain. This structure should not be accessible by the public. This structure should be designed to minimize viewing obstructions. Alternatively, the City should consider realignment of the utilities to below the bridge. Restoration works to heritage elements should be reviewed to ensure they comply with allowable works under the Ontario Heritage Act. To learn more about the study, please visit guelph.ca/construction or contact: Andrew Janes, P.Eng. Project Engineer Supervisor City of Guelph x 2338; andrew.janes@guelph.ca Jack Turner, P.Eng. Project Manager GM BluePlan Engineering Limited ; jack.turner@gmblueplan.ca A maintenance plan, which includes mitigating impacts to the natural environment, should be developed for the new bridge structure.