Design Solutions for the Royal Alexandra Bridge

DESIGN SOLUTIONS FOR THE ROYAL ALEXANDRA BRIDGE

FOR: PUBLIC SERVICES & PROCUREMENT CANADA

EXSPAN STRUCTURAL

CONSULTING SERVICES

CHRISTOPHE CHAN SING HENNY DUONG KINGTON CHU SOFIA AN

JULY 22, 2019

Christophe Chan Sing ExSpan Senior Project Manager 200 University Ave West Waterloo, Ontario Canada N2L 3G1 July 22, 2019 Dr. Nadine Ibrahim Senior Project Engineer Public Services and Procurement Canada 140 O'Connor Street Ottawa, Ontario Canada K1A 0S5 Dear Dr. Nadine Ibrahim: The Royal Alexandra Interprovincial Bridge is deteriorating and multiple rehabilitations have taken place over the last decade in an effort to extend the bridge’s service life. These constant rehabilitations have been costly to both the federal government and the local communities of Ottawa and Gatineau in terms of overall construction expense and traffic congestion. Our scope of work for Phase I of this project include an evaluation of possible design options related to either reconstructing the existing bridge or constructing a new complementary bridge. The evaluation was performed by analyzing and comparing in a weighted decision matrix each design option’s life cycle cost, innovativeness, construction impact, traffic flow, excess strength, and ability to preserve the existing bridge’s heritage. It was determined that constructing a box girder bridge to complement the existing bridge is the preferable option over reconstructing or continuing to rehabilitate the current bridge. Therefore, it is recommended that the complementary box girder bridge is chosen for Phase II of the project where it will undergo detailed design, be structurally analyzed, and have construction plans produced for it. Our technical advisor, Dr. Maria Anna Polak, was a great resource in guiding us through the first phase of this project. This technical report was written by our team at ExSpan and has not received academic credit at the University of Waterloo or any other academic institution. Yours sincerely,

Christophe Chan Sing Henny Duong Senior Project Manager Technical Analyst

Kington Chu An Su Hyun Structural Analyst Structural Designer

DESIGN SOLUTIONS FOR THE ROYAL ALEXANDRA BRIDGE

EXSPAN STRUCTURAL CONSULTING SERVICES

CHRISTOPHE CHAN SING HENNY DUONG KINGTON CHU AN SU HYUN

JULY 2019

Summary The Alexandra Bridge is a steel truss cantilever bridge that spans over the Ottawa River between Ottawa and Gatineau. It was originally built in 1900 by the Canadian Pacific Railway. The bridge has been subjected to several rehabilitation programs in the past ten years due to its age. The constant construction work and road closures have had a negative impact on the traffic around the bridge. The main problem is the fact that the traffic on the bridge is continuously increasing while the bridge is deteriorating rapidly and will need more rehabilitations in the future. ExSpan was brought in as a consultant to assess the problem and come up with a solution. Three alternatives were proposed as potential solutions. The first one is to demolish the Alexandra bridge and reconstruct a new bridge in the same location. The new designs that were considered are an extradosed bridge, tied-arch bridge, and cantilever truss bridge. The second solution is to repurpose the existing bridge and build a complementary bridge, which is a box girder bridge, in the same area. The third solution is to continue the existing rehabilitation programs to help strengthen the existing bridge. The four new designs and the continued rehabilitation were compared using a weighted matrix. The criteria that were used in the comparison are the Bridge Life Cycle Cost Analysis (BLCCA), heritage conservation, innovation, construction impact, traffic flow, and excess strength. The box girder obtained the highest score according to the weighted matrix and was thus chosen as the final design for Phase II of the project. A detailed design of both the superstructure of the bridge and its foundations will be performed using various codes and regulations. Structural drawings and construction plans will also be produced.

Acknowledgements Special thanks to our technical advisor, Dr. Maria Anna Polak, for her contributions during Phase I of this project. In addition to providing technical guidance along the way, Dr. Maria Anna Polak also assisted in the brainstorming of possible design concepts for both the reconstruction of the Alexandra Bridge and the construction of a complementary bridge.

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Table of Contents 1 Introduction ...... 1 1.1 Background ...... 1 1.2 Project Requirements ...... 2 1.2.1 Demolition and Reconstruction ...... 2 1.2.2 Repurposing and Complementary Bridge ...... 2 1.2.3 Retrofitting and Rehabilitation ...... 3 1.3 Scope of Work ...... 3 2 Design Constraints ...... 4 2.1 Heritage Conservation ...... 4 2.1.1 Design or Conceptual Values...... 5 2.1.2 Materialistic Values ...... 6 2.1.3 Holistic Contextual Values ...... 6 3 Feasibility Analysis ...... 8 4 Bridge Life-Cycle Cost Analysis ...... 9 4.1 Material and Construction Cost...... 9 4.2 Maintenance Cost ...... 10 4.3 Economic Benefit ...... 10 4.4 Net Present Value ...... 11 5 Traffic Flow Impact ...... 11 5.1 Vehicular Traffic ...... 12 5.2 Light-Railway Transit Traffic ...... 12 5.3 Pedestrian Traffic ...... 13 6 Construction Impact ...... 13 7 Conceptual Designs ...... 14 7.1 Cantilever Truss Bridge ...... 15 7.1.1 Design Values ...... 15 7.1.2 Contextual Values ...... 16 7.1.3 Traffic Flow ...... 16 7.1.4 Innovation ...... 16 7.1.5 Cost ...... 16 7.1.6 Construction ...... 17 7.1.7 Strength ...... 17

7.2 Extradosed Bridge ...... 17 7.2.1 Design Values ...... 18 7.2.2 Contextual Values ...... 18 7.2.3 Traffic Flow ...... 19 7.2.4 Innovation ...... 19 7.2.5 Cost ...... 19 7.2.6 Construction ...... 20 7.2.7 Strength ...... 20 7.3 Tied-Arch Truss Bridge ...... 20 7.3.1 Design Values ...... 21 7.3.2 Contextual Values ...... 21 7.3.3 Traffic Flow ...... 21 7.3.4 Innovation ...... 22 7.3.5 Cost ...... 22 7.3.6 Construction ...... 22 7.3.7 Strength ...... 22 7.4 Box Girder Bridge ...... 22 7.4.1 Design Values ...... 23 7.4.2 Contextual Values ...... 23 7.4.3 Traffic Flow ...... 24 7.4.4 Innovation ...... 24 7.4.5 Cost ...... 24 7.4.6 Construction ...... 24 7.4.7 Strength ...... 25 7.5 Rehabilitation of Existing Bridge ...... 25 7.5.1 Design Values ...... 25 7.5.2 Contextual Values ...... 25 7.5.3 Traffic Flow ...... 25 7.5.4 Innovation ...... 26 7.5.5 Cost ...... 26 7.5.6 Construction ...... 26 7.5.7 Strength ...... 26 8 Weighted Decision Matrix Comparison ...... 26

9 Conclusions and Recommendations ...... 27 10 References and Appendices ...... 29

Table of Figures Figure 1: Scope of Work (Google Maps, 2019) ...... 4 Figure 2: Canadian Museum of Civilization (Porter, M., 2015) ...... 7 Figure 3: Approximate Locations for Complementary Bridge (Google Earth, 2019) ...... 8 Figure 4: Tentatively Proposed Lane Arrangement ...... 13 Figure 5: Cantilever Truss Bridge Design – Elevation Profile ...... 15 Figure 6: Extradosed Bridge Design – Elevation Profile ...... 17 Figure 7: Extradosed Bridge Design – Cross-Section Profile ...... 18 Figure 8: Tied-Arch Bridge Design – Elevation Profile ...... 20 Figure 9: Tied-Arch Bridge Design – Cross-Section Profile ...... 21 Figure 10: Box Girder Bridge Design – Cross-Section Profile ...... 23

List of Tables

Table 1. Weighted Decision Matrix ...... 267

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1 Introduction 1.1 Background The Royal Alexandra Interprovincial Bridge, hereby addressed simply as the Alexandra Bridge, is an approximately 560-metre-long steel truss cantilever bridge originally constructed in 1900 by the Canadian Pacific Railway. The bridge is notably asymmetric and is of a main cantilever span and three additional truss spans.

Spanning across the Ottawa river between the cities of Ottawa, Ontario, and Gatineau, Quebec, the Alexandra Bridge was originally designed for electric trolley and rail use until the closure of the Ottawa Union Station in the late 1960s, where it was rehabilitated to accommodate vehicular and pedestrian traffic.

In 1970, the Canadian Pacific Railway turned over ownership of the bridge to the National Capital Commission and was ultimately taken over by the Government of Canada under Public Services and Procurement Canada (PSPC). In 1995, the Canadian Society for Civil Engineering designated the bridge as a Canadian National Historic Civil Engineering Site, where it remains as one of Ottawa and Gatineau’s local heritage icons (CSCE, 2017).

Since the start of the 21st century, the Alexandra bridge has been a part of multiple 1- and 2- yearlong rehabilitation programs focused on restoring piers, girders, portions of the main deck, and steel members surrounding the piers for the purpose of extending the bridge’s service life. Each rehabilitation project has included traffic management in the form of temporary and/or permanent lane closures.

The Alexandra Bridge is currently responsible for approximately 15% of the total vehicular traffic and 40% of the total pedestrian traffic between Ottawa and Gatineau. The pedestrian traffic across the Alexandra Bridge is the most out of all interprovincial bridges between Ottawa and Gatineau (PSPC, 2018).

The objective of the designs is to provide alternative options and decide the most feasible solution to reduce future expenses, improve the structural strength, traffic flow, and preserve the heritage of the bridge. Each design has a different purpose and background which has been used in a weighted matrix to determine the best solution for the project.

1.2 Project Requirements The lanes closures on the Alexandra Bridge associated with the structural rehabilitation projects detrimentally impact the immediate flow of traffic between Ottawa and Gatineau and causes congestions both on the Alexandra Bridge as well as on the other four (4) existing interprovincial bridges. In order to address the deteriorating structural integrity of the bridge as well as the ever- increasing traffic demand (DCN News Services, 2019) says that there has been a 15,000 vehicles/day increase across the bridge since 2015 and is expected to continue to rise in the future), ExSpan has identified three possible alternatives and are as follows:

1. Completely demolition and reconstruction of a bridge in place of the Alexandra Bridge; 2. Repurposing the existing Alexandra Bridge and building a complementary companion bridge within the immediate vicinity; and, 3. Continuing the existing retrofit and rehabilitation programs planned for strengthening the bridge

All three (3) proposed plans listed above have the major overarching objectives of minimizing the need for future rehabilitation programs, improving the increasing traffic demand and congestion, and finally to preserve and honour the local heritage and identity of the Alexandra Bridge.

1.2.1 Demolition and Reconstruction The demolition and reconstruction of a new bridge in place of the existing Alexandra Bridge will be able to greatly extend the service life of the bridge. The reconstruction of the Alexandra Bridge could accommodate rail systems for future plans of the major Ottawa-Gatineau LRT project planned for 2028. While the reconstruction of the bridge would retain major identity visuals, traffic demand would be accommodated by adding in additional lanes for vehicular and/or pedestrian traffic, thereby eliminating the need for occasional alternate-lane switching.

1.2.2 Repurposing and Complementary Bridge Building a complementary bridge has a focus on relieving the traffic demand across the Alexandra Bridge without drawing attention away from the historic structure; the companion bridge would be built to accommodate for the majority of vehicular traffic while the Alexandra Bridge would be repurposed for pedestrian and cyclist use. The companion bridge would be built with complementary aesthetic appeal without detracting from the Alexandra Bridge.

1.2.3 Retrofitting and Rehabilitation The rehabilitation will expand upon the current structural rehabilitation planned for the bridge. PSPC expects there to be 2-3 more rehabilitation programs aimed at repairing the steel girders, metal deck, and other structural steel members in the next 3 years (PSPC, Communications, 2019). The major rehabilitation plan will be focused on a holistic rehabilitation of the entire bridge aimed at expanding the service life of the existing bridge until any planned future bridges are erected in other locations (Department of Finance, 2019).

1.3 Scope of Work The scope of work on the existing Alexandra Bridge will be limited to the portion spanning the Ottawa River and joining the cities Ottawa and Gatineau, constrained by Laurier Street to the west and Sussex Drive to the east. All options will consider the structural and geotechnical components of any additional retrofitting or construction. Associated roadwork rehabilitation and hydraulic engineering analyses will be considered outside the scope of the project. The repurposing of the existing bridge and construction of a complementary bridge has additional specific portions to the scope of work and includes construction zones for the complementary bridge limited immediate local vicinity of the Alexandra Bridge, bounded by the Macdonald- Cartier Bridge to the north and the Portage Bridge to the south-west. In order to not develop increased local scour to adjacent bridges’ piers, the companion bridge will be built within approximately 150 m out from the existing Alexandra Bridge. Figure 1 below illustrates the surrounding geography of the Alexandra Bridge:

Figure 1: Scope of Work (Google Maps, 2019)

2 Design Constraints 2.1 Heritage Conservation In Canada, ‘heritage conservation’ addresses the desires to identify with, protect, and promote the connections of tangible or intangible assets to Canadian historical roots. Heritage conservation can be largely broken down into three main ideas, including the cultural importance and value of: 1. a design idea or concept; 2. a specific material or artefact; and, 3. a contextual view based on a holistic approach of the surrounding environment.

The basis of the three above ideas have been stripped from three fundamental heritage conservation case studies of Canada and can be found in further detail in Appendix A.

The Alexandra Bridge boasts a colourful history for holding the title for the longest-spanning Canadian cantilever bridge at its time of construction in 1901 (“Alexandra Bridge”, n.d.) until the completion of its sister, the Quebec Bridge, in 1919 (“Quebec Bridge”, n.d.). Unlike the Quebec Bridge, the Alexandra Bridge is not designated as a cultural heritage value or interest under Part IV of the Ontario Heritage Act, and is furthermore not designated as a National Historic Site of Canada (PSPC, n.d.). While the bridge enjoys moderate support as a National Historic Civil Engineering Site of Canada from 1 of the 12 objectives listed by the Canadian Society for Civil Engineering (CSCE, 2019), its sole status as an interprovincial bridge connecting Ottawa and Gatineau provides no explicit restriction against any potential alteration, modification, or outright demolition of the bridge.

However, ExSpan recognizes the local cultural significance of the Alexandra Bridge and its core identity as the iconic bridge situated just off the banks of the Rideau Canal and beside Canada’s parliament, Capital Hill. Its close proximity to multiple legal government buildings as well as popular tourist sites has cemented itself as one of the defining infrastructural features of Ottawa. ExSpan is intent on honouring its identity by applying Canadian principles of heritage conservation while addressing the current structural and traffic needs surrounding the Alexandra Bridge.

2.1.1 Design or Conceptual Values The major design value that the Alexandra Bridge possesses is its long cantilever truss span design. It is expected that any major reconstruction of this bridge would include, at minimum, its iconic structural cantilever. Further efforts to conserve original history would be to include a replica of the structural design, though is not required in lieu of Case Study I found in Appendix A.

2.1.2 Materialistic Values In lieu of Case Study I found in Appendix A, the steel used to build the original the Alexandra Bridge has been established to not be of any major historical significance and may be omitted from consideration. There was found to be no other materialistic values of significance associated with the bridge. Thus, materialistic values will not be considered for any of the design options.

2.1.3 Holistic Contextual Values The contextual values of the Alexandra Bridge are multi-pronged, and includes the original intent of the bridge, the various uses of the bridge, and its architectural stylistics when compared alongside the urban architecture of both Ottawa and Gatineau on the embankments of the Ottawa River.

2.1.3.1 Original Intent Originally designed to carry Canadian Pacific Railway trains, local trolley services, and carriage traffic, the bridge was eventually modified and now only offers vehicular and pedestrian traffic (PSPC, 2018). Honouring its original intents could see a new design offering light-railway transit carrying capabilities through Ottawa and Gatineau as desired by Gatineau’s mayor, Pedneaud- Jobin (Brown, D., 2018), Quebec’s Premier Couillard, and Ottawa’s mayor, Watson (CBC, 2019).

2.1.3.2 Current Use The Alexandra Bridge currently allows for the passage of heavy vehicular traffic and pedestrian traffic (PSPC, 2018). It is a designated official route between Gatineau and Ottawa for the Trans Canada Trail, established in 1992 (“Ottawa River Pathway”, n.d.). Future designs should consider the ability to carry pedestrian, cyclist, and equestrian traffic. Additionally, the Alexandra Bridge notably links major bike routes throughout both cities, including the Voyageur Pathway, connecting the Aylmer and Gatineau Sectors, and the River Pathway, connecting Carling Avenue and the downtown core (“Sentier des Voyageurs Pathway”, n.d.).

2.1.3.3 Architectural Style The architecture in Ottawa tends to be formal and functional. Standard governmental buildings are typically complemented by Ottawa’s sub-architectural styles, including Gothic and Celtic picturesque aesthetics stemming from the Romantic era. The vast majority of original historical buildings developed with the initial founding of Ottawa in the early 19th century has been demolished or renovated during the transformation in the early 1960s, and outside of significant structures like the Parliament Hill building, institutional government buildings typically adhere to a late 20th century style (Carleton University, 2016). In recent years – most recently with the appointment of Pierre Trudeau as Prime Minister – government buildings surrounding Parliament Hill has experienced a shift to embrace modernism with the construction of the Place du Portage and Terrasses de la Chaudière in Quebec. Around the government buildings are structures with internationally acclaimed architectural success in a postmodern style, and includes three of the most dominant buildings associated with the Alexandra Bridge: the Canadian Museum of Civilization, the National Gallery of Canada, and the Canadian War Museum. Figure 2 below depicts the architectural style of the Canadian Museum of Civilization:

Figure 2: Canadian Museum of Civilization (Porter, M., 2015)

It is apparent that the current trend of Canadian architecture in the capital is shifting to embrace contemporary or even post-modernist styles that complement the structured, formal atmosphere of traditional government buildings (Leblanc, D., 2018).

3 Feasibility Analysis A feasibility analysis on the construction of a complementary bridge was conducted and includes engineering proximity due to piers and the surrounding use and local heritage. Based on the completed studies, three (3) locations were found suitable for the construction of a complementary bridge. The feasibility analysis conducted may be found in full in Appendix B.

Figure 3 below depicts the suitable locations established by the feasibility analysis:

Figure 3: Approximate Locations for Complementary Bridge (Google Earth, 2019)

Marked in blue are the property parcels of either protected heritage sites or sites of local significance, both hatched in red. The three tentative locations have been marked in black, and are detailed as follows:

1. Location (1) offers a starting point on Nepean Point, at the same location as the start of the existing bridge. This location will allow the two bridges to share one merge point. 2. Location (2) joins the middle portion between the Parliament Hill buildings and the legal buildings at a lower elevation than the nearby roadwork. It joins Gatineau at a similar elevation near an existing factory plant. 3. Location (3) is similar to location 2 but offers the ability to construct a pier on an existing island in the midsection of the Ottawa River.

4 Bridge Life-Cycle Cost Analysis The cost of a bridge is an important factor when deciding which design option is best for the cities of Ottawa and Gatineau. Costs beyond just the initial construction need to be considered as well. A bridge life cycle cost analysis (BLCCA) includes the cost of constructing and maintaining a bridge during its life cycle (National Academies of Sciences, Engineering, and Medicine, 2013) and is necessary to evaluate how economical each option is in the long-term.

4.1 Material and Construction Cost Each design was composed of unique styles and materials to incorporate innovation, heritage conservation, total cost, and strength. Quantity take-offs were performed using CAD to estimate the amount of material that is required for each design option. All planning and design costs were calculated using a bridge construction cost aid (WSDOT, 2019). In addition to the construction cost aid, a research study was used to find the unit cost of steel cables (Kris Mermigas, K., 2008). The parts of a bridge that cost the most to produce and construct were considered in the estimate including the concrete, steel, girders, cables, and parapet walls.

4.2 Maintenance Cost Regular maintenance is necessary to preserve the service life and overall structure of a bridge. High priority maintenance items and associated costs were determined using:

 Municipal Bridge Inspection Report (RJ Burnside, 2016)  Inspection and Maintenance of Bridge Stay Cable System (NCHRP, 2005)

The frequency of each maintenance item was determined using:

 Texas department of transportation (TxDOT, 2019)  University of Purdue (Yanez, 2015)

The frequencies range from annually to every 10 years depending on the inspection results using the bridge condition index (BCI). The cost of maintenance for a design option was estimated by taking the cost of that maintenance item for an existing bridge and scaling it to match the design option. General cleaning of the bearings, connections, and substructure; removal of vegetation; and erosion control of the substructure were scaled by the total width of the bridge. This is because these maintenance items generally occur near the abutment and the abutment generally spans the width of the bridge. On the other hand, the cleaning of seals, wearing surfaces, and deck top as well as the routing and sealing of the decks were scaled by the total area. This is because for these maintenance items, an inspection of the entire deck is required to locate cracks, holes, and the accumulation of debris in expansion joints. For designs containing cables, the maintenance cost used for the cables was a single cost identified for testing a set number of cables per bridge regardless of how many more cables the bridge has.

4.3 Economic Benefit Both the reconstruction of the Alexandra Bridge and the construction of the complementary bridge have an added economic benefit of reducing traffic congestion as a result of the increased number of lanes in the designs. By considering this economic benefit, the present value of each design’s life cycle cost analysis can be more accurately compared to the cost of continuing to rehabilitate the existing bridge than if only the expenses were considered.

A study on the traffic congestion between Ottawa and Gatineau was performed by Transport Canada Environmental Affairs. It was found that the total cost of congestion ranged from $39.6 million to $88.6 million after considering delays, wasted fuel, and greenhouse gas emissions (Transport Canada Environmental Affairs, 2007). It is assumed that total congestion will reduce by 20% as a result of the increase in traffic capacity brought by the proposed design options.

4.4 Net Present Value To estimate the present value of each alternative, it was necessary to assume a time period and an interest rate for the money invested into construction and maintenance. The life cycle cost of each design was analyzed for an interest rate of 5% compounded annually over a period of 50 years.

A net present value was determined from the difference between the present value of the benefits and costs. A positive NPV from the BLCCA of a design indicates that the project is financially worth pursuing in the long-term whereas a negative NPV indicates it is uneconomical. Therefore, the design with a greater NPV is the financially stronger long-term option.

5 Traffic Flow Impact Since the large increase in population in Ottawa and Gatineau in the mid-1900s, the need for additional infrastructure linking the two cities has also risen. Originally designed to carry no vehicular traffic, in 2009 (Malatest, R., 2009) it was found that the Alexandra Bridge carried approximately 8000 – 9000 vehicles (“Peak Auto Demand Projections”, n.d.) on a daily basis and by 2018, with the rapid development of condos and other residential buildings in Ottawa’s downtown core (Leeuwen, J. V., Minto, 2017), this number has jumped to 22000 (PSPC, 2018).

It is expected with the continued development of Ottawa and Gatineau that this number will continue to rise (“NCR Crossings”, n.d.), and that either additional bridges or modes of transportation between the two cities are required (“Interprovincial Crossings”, n.d.).

Currently, the Alexandra Bridge operates using three (3) lanes, with:

 One (1) 5.5-metre lane for eastbound traffic into Gatineau;  One (1) 7.9-metre lane for westbound traffic into Ottawa; and  One (1) 5.6-metre lane for eastbound and westbound pedestrian and cyclist traffic.

Since the current iteration of the bridge has been retrofitted from the original rail-designed bridge, the current lane widths provided for pedestrian and vehicular traffic is greatly overstated, and as such, new specifications for lane widths will be established.

5.1 Vehicular Traffic Following the City of Toronto guidelines for lane widths, updated in 2017, the average width for a through lane with expected traffic travelling at 60km/hr was taken at 3.25-metres (City of Toronto, 2017). Based on a PSPC-developed traffic studies on the Alexandra Bridge between 2012 – 2016 (PSPC, 2018), traffic is typically much heavier westbound into Ottawa, except during the afternoon rush hour, where traffic evens out.

Keeping this in mind, ExSpan proposes the addition of one vehicular traffic lane, raising the total number of lanes dedicated to vehicular traffic to three. Two of the lanes will be for westbound traffic into Ottawa with accordance to the PSPC traffic study and one lane will be for eastbound traffic into Gatineau. While one additional lane adequately addresses the current need for traffic flow between Ottawa and Gatineau, it does not address the continued need for the expected traffic increase in the future.

5.2 Light-Railway Transit Traffic In order to address the required need for additional traffic, ExSpan has decided to move forwards with plans to adopt Quebec’s proposed light-railway transit plans linking Ottawa and Gatineau through the Alexandra Bridge. It is expected that the two dedicated LRT lanes into Ottawa’s downtown core will entice commuters to choose transit over vehicular traffic, easing up expected congestion on the three bridges in the immediate vicinity of the Alexandra Bridge. By following Canada’s standard manufacturer for light-railway transit, it was established that a lane width of 3.650-metres (“City: Transit Buses”, n.d.) was required for a single LRT lane (Ink, S., 2016).

5.3 Pedestrian Traffic A minimum one-way pedestrian and cyclist walkway was established to be 1.625-metres, subject to change.

With the above criteria established, the tentatively proposed lane arrangement for a replacement of the Alexandra Bridge has been depicted in Figure 4 below:

Figure 4: Tentatively Proposed Lane Arrangement

In order to remain conservative and to account for additional structural components, a 2-metre strip of middle-lane width was added for LRT support, and a further 1.7-metres of various structural components were considered when establishing calculations.

6 Construction Impact The rehabilitation of the Alexandra Bridge or construction of a new bridge should aim at minimizing construction impacts. The time of construction should be reduced as much as possible as diversions impact road users and generate more traffic around the construction area. Construction also impacts the environment as it disrupts wildlife, changes the topography of the area and pollutes the environment. Moreover, the neighbouring area is also affected by construction noises, movement of heavy equipment, and muddy pavements.

7 Conceptual Designs Conceptual designs were produced for the reconstruction of the existing bridge and for the construction of the complementary bridge. The five proposed options to be evaluated in the first phase of this project are:

1) The cantilever truss bridge; 2) the extradosed bridge; 3) the tied-arch truss bridge; 4) the box girder bridge; and, 5) the continued rehabilitation of the existing bridge.

These five concepts will be evaluated based on a set of criteria that are weighed according to their priority to this project. These criteria include:

1) Bridge life cycle cost analysis (30%) 2) Heritage conservation (17.5%) 3) Innovation (17.5%) 4) Construction impact (15%) 5) Traffic flow (12.5%) 6) Excess strength (7.5%)

ExSpan prioritizes cost minimization for the designs because the optimal design needs to be economically feasible for the client to pursue. Therefore, the bridge life cycle cost analysis is the most heavily weighed criteria. ExSpan strives to deliver the most innovative solutions, but the firm also understands that the local heritage needs to be preserved while doing so. As a result, it was determined that striking a balance between the preservation of the local heritage and innovation would be ideal and thus, they are both given equal second priority. Construction impact was deemed to be the fourth greatest priority when evaluating the designs since it negatively affects the locals by congesting traffic and disrupting the environment throughout the duration of construction which can be extremely costly. The traffic flow follows closely as the next priority since traffic between Ottawa and Gatineau has been experiencing growth over the years and greater traffic flow provided by the designs would be beneficial. Finally, the excess strength is the lowest priority. While excess strength may increase the factor of safety of the bridge, the bridges will be designed for a minimum strength with an already high factor of safety

14 that is compliant with the bridge codes in Phase II; therefore, any additional strength would not provide a noticeable effect or financial return.

7.1 Cantilever Truss Bridge A cantilever truss bridge was chosen as a possible design option to preserve the heritage of the existing Alexandra Bridge by mimicking as many features of the original bridge as possible while still incorporating modern techniques and technologies to the new design. A cantilever design allows the bridge to be constructed with minimal falsework and piers (Dublin City Council, 2019) while the inclusion of a steel truss allows for a greater strength-to-weight ratio (Bridge Masters, 2017). Figure 5 below shows an elevation view of the cantilever truss bridge option.

Figure 5: Cantilever Truss Bridge Design – Elevation Profile

In addition to the implementation of new techniques and technologies, the new proposed cantilever truss bridge will also differ from the existing Alexandra Bridge by having fewer piers, a longer cantilever span, and a larger singular truss as shown in the elevation view.

7.1.1 Design Values The reconstruction of a cantilever truss bridge adheres closely to the original design intent of the bridge – a long-spanning cantilever over the Ottawa River joining Ottawa with Gatineau. With new engineering and design practises, ExSpan aims to eliminate the asymmetry of the bridge by removing the original Truss ‘B’ Span and Truss ‘A’ Span and expanding the central span of the new cantilever. Symbolically, this design embodies the relationship between the two sides it connects; there are two main piers and truss superstructures – one on either side of the centre of

15 the river for Ottawa and Gatineau – and there is one central bridge span, representing the long- standing history of the two cities.

7.1.2 Contextual Values As the design retains much of the original bridge’s cantilever truss design, it will fit well with the background of the formal government buildings on both sides of the river. The new, larger piers and cantilever truss superstructure exemplifies the overall growth that Ottawa and Gatineau have experienced in the past century. The bridge will carry both vehicular and light-railway transit. One pedestrian lane will remain open as the official route for the Trans Canada Trail. For the heritage conservation category, the cantilever truss bridge design was given a rank of 8.

7.1.3 Traffic Flow All designs under the reconstruction option aims to address the increasing traffic flow needs by developing a wide-lane multi-use bridge to allow for light-railway transit, ordinary vehicular traffic, as well as pedestrian traffic. For the traffic flow category, the cantilever truss bridge design was given a rank of 9.

7.1.4 Innovation The new cantilever truss design will allow for a larger suspended midspan. For the innovation category, the cantilever truss bridge design was given a rank of 2.5.

7.1.5 Cost The greatest costs for the cantilever truss option were found to be the reinforced concrete steel deck, the steel truss, and the overall maintenance of the structure. The construction cost of the bridge is estimated to be approximately $121 million and the maintenance cost is estimated to be $4.6 million. The estimated net present value of the design option is approximately $20.5 million after considering the design’s benefit in reducing traffic congestion. A more detailed cost breakdown of the estimated cost and net present value can be found in Appendix C. For the BLCCA category, the cantilever truss bridge design was given a rank of 10.

7.1.6 Construction The construction time for the cantilever truss was estimated to be one and a half years based on similar bridges such as the Matthew E. Welsh bridge (Bridges & Tunnels, n.d.), Sewickley bridge (Sewickley Valley Historical Society, n.d.) and Lincoln Trail bridge (Bridges & Tunnels, n.d.).

For the construction impact category, the cantilever truss bridge design was given a rank of 10.

7.1.7 Strength Cantilever truss bridges are strong because loads are distributed across the entire bridge structure by using a metal structure made up of triangular units.

For the excess strength category, the cantilever truss bridge design was given a rank of 10.

7.2 Extradosed Bridge An extradosed bridge design has been selected as one of the possible demolitions and reconstruction design options due to its qualities of engineering innovation, promotion of current architectural trends, and reduction in material cost. As a medium- to long-span bridge, an extradosed is more akin to a combination of a prestressed box girder bridge and a cable-stayed bridge, with its cables act as external prestressing tendons. Compared to a cable-stayed bridge of similar design, an extradosed bridge design sports a much lower overall height. Compared to a box-girder bridge of similar design, an extradosed bridge design is able to retain a lower deck height while still meeting the navigational clearance requirements specified in the Ottawa River.

Figure 6 below depicts a side profile of the proposed bridge design across the Ottawa River:

Figure 6: Extradosed Bridge Design – Elevation Profile

Figure 7 below depicts the tentative cross-section of the proposed bridge at midspan and at a pier:

Figure 7: Extradosed Bridge Design – Cross-Section Profile

Design specifications and all calculations were established or estimated in reference to several completed extradosed bridge designs of similar nature (Sing Pahuja, J., n.d.; Mermigas, 2008). Specifications are subject to change if selected as the final bridge design.

7.2.1 Design Values The extradosed bridge does not retain any of the fundamental components of the original cantilever truss bridge design.

7.2.2 Contextual Values The extradosed bridge design embodies the changing style of Ottawa and Gatineau. As a hybrid combination of a cable-stayed bridge and a box-girder bridge, the extradosed bridge manages to encompass the monotonous, grey, and formal appearance of government buildings using a standard concrete deck combined with contemporary design methods displayed in a fan of low, short-angled cables. While this design does not preserve the original design values of the bridge, the extradosed bridge instead promotes the change from traditional to contemporary views, similar to the current shift in architecture in Ottawa’s downtown core. The bridge will carry both vehicular and light-railway transit. One pedestrian lane will remain open as the official route for the Trans Canada Trail. 18

For the heritage conservation category, the extradosed bridge design was given a ranking of 5.

7.2.3 Traffic Flow All designs under the reconstruction option aims to address the increasing traffic flow needs by developing a wide-lane multi-use bridge to allow for light-railway transit, ordinary vehicular traffic, as well as pedestrian traffic. For the traffic flow category, the extradosed bridge design was given a ranking 9.

7.2.4 Innovation The extradosed bridge utilizes a combination of elements borrowed from both a cable-stayed bridge and a box-girder bridge. Though similar to a cable-stayed bridge, the cables on an extradosed bridge are prestressed in tension and can be considered part of the superstructure of the bridge. It is a new type of bridge and will be the first of its kind in Canada to span upwards of 300 metres. With the tendons installed at central piers, the extradosed bridge allows for an overall height while maintain acceptable navigation clearance by greatly reducing the depth of its box girder at midspan, where the depth can vary to as much as half of its depth at a pier. The innovation of using an extradosed bridge allows for a lower tower height than that of a standard cable-stayed bridge and does not detract from the surrounding environment, while the longer spans created by the prestressed cables mimics the spans of the original bridge.

7.2.5 Cost The extradosed bridge option’s greatest costs are from the reinforced concrete deck, the concrete box girder, and the maintenance costs. The initial construction cost was estimated to be $140.2 million and the present value maintenance cost was estimated to be $4.7 million. The estimated net present value is approximately $1.2 million after considering the reduction in traffic congestion provided by the new design. A more detailed breakdown of the cost and value of this design option is provided in Appendix C. The extradosed bridge design scores 7 for innovation.

7.2.6 Construction The extradosed bridge was determined to take three years to construct based on the Sunniberg bridge (International Association for Bridge and Structural Engineering, 2015), Golden Ears bridge (Structurae, n.d.), and Southern bridge (The Baltic Times, 2008).

The extradosed bridge design scores 10 for construction impact.

7.2.7 Strength Extradosed bridges are similar to box girder bridges except that they incorporate elements of a cable-stayed bridge. This makes the extradosed bridge stronger than the box girder bridge since the cables carry the weight of the deck and reduces the chance of failure at the midspan.

The extradosed bridge design scores 10 for excess strength.

7.3 Tied-Arch Truss Bridge The tied-arch bridge is one of the possible demolition and reconstruction options as it embraces the new, modern and post-modernist architectural styles that are starting to pop up around Capital Hill. The tied-arch bridge is a variant of the arch bridge where the ends of the arches are tied by either the deck or separate tie rods. Thus, the horizontal loads are carried by the deck or tie rods and this reduces the loads on the foundations. The bridge design for this project consists of two spans that cover the entire width of the river with a single pier in the middle. The deck height will be the same as that of the existing bridge while the horizontal clearance will be longer, therefore meeting the navigational clearance requirements specified in the Ottawa River. Figure 8 below shows the side profile of the proposed tied-arch bridge.

Figure 8: Tied-Arch Bridge Design – Elevation Profile

Figure 9 below illustrates the suggested cross-section of the proposed bridge.

Figure 9: Tied-Arch Bridge Design – Cross-Section Profile

7.3.1 Design Values The tied-arch bridge does not retain any of the fundamental components of the original cantilever truss bridge design.

7.3.2 Contextual Values The tied-arch bridge design looks to embrace the new, modern and post-modernist architectural styles starting to populate around Capital Hill, including the National Gallery of Canada and the Canadian Museum of Civilization. By utilizing multiple curved arches for the main spans of the bridge, it complements the existing curved architecture of the National Gallery of Canada and the interior cyclonic design of the Museum of Civilization. Like the extradosed bridge, the tied- arch bridge does not look to preserve the original design values of the bridge and instead promotes the change to contemporary modernist views of the downtown core. The bridge will carry both vehicular and light-railway transit. One pedestrian lane will remain open as the official route for the Trans Canada Trail. The tied-arch bridge design scores 5 for heritage conservation.

7.3.3 Traffic Flow All designs under the reconstruction option aims to address the increasing traffic flow needs by developing a wide-lane multi-use bridge to allow for light-railway transit, ordinary vehicular traffic, as well as pedestrian traffic. The tied-arch bridge design scores 9 for traffic flow. 21

7.3.4 Innovation The tied-arch bridge features cantilever arms on either side of the piers, and is not commonly seen in Canada. The tied-arch bridge scores 2.5 for innovation.

7.3.5 Cost The tied-arch bridge design has a greater initial construction cost of approximately $129 million and a relatively high present value maintenance cost of approximately $4.4 million. The present value life cycle cost was therefore found to be approximately $133 million. The estimated net present value of this design option is approximately $13.2 million after considering the reduction in traffic congestion. Appendix C provides a detailed breakdown of the cost and value of this option. The tied-arch bridge scores 8.3 for its BLCCA.

7.3.6 Construction The time of construction for the tied-arch bridge was estimated to be four and a half years based on the construction times for similar bridges such as the Fort Pitt bridge (Brookline Connection, n.d.) and the Fremont bridge (Dave Knows Portland, 2011).

The tied-arch bridge scores 7 for construction impact.

7.3.7 Strength Tied-arch bridges are stronger than beam bridges because the deck weight is carried by the cables which then transfer the loads to the arch. The ends of the arch are held by either the deck or separate tie rods which transfer the loads to the supports.

The tied-arch bridge scores 10 for excess strength.

7.4 Box Girder Bridge The box girder beam bridge is the design option for the complementary bridge alternative. The existing Alexandra Bridge will be preserved and repurposed as a pedestrian bridge and a box

22 girder beam bridge will be constructed nearby. The aim of this design is to keep eyes on the main Alexandra Bridge as one of the iconic pieces of structural engineering feats between Ottawa and Gatineau. Furthermore, box girders were chosen as a design since the bridge spans along the Ottawa river and is exposed to constant moisture; the girder design helps to reduce moisture and chemical build up from the water and vehicles. The bridge also will meet the navigational clearance requirements, thus the length will be increased and adjusted accordingly. In addition, the cross section of the bridge design is shown in Figure 10.

Figure 10: Box Girder Bridge Design – Cross-Section Profile

7.4.1 Design Values The box-girder bridge retains all of the original design and superstructure, as none of it will be removed with the addition of this box-girder bridge.

7.4.2 Contextual Values The box-girder bridge aims to preserve all of the aspects of the original bridge by not attempting any reconstruction on it. Instead, by building a complementary bridge in proximity to a repurposed original Alexandra Bridge, it aims to preserve and promote the history associated with the original cantilever bridge. Built as a simple beam, it will not detract from the identity of the Alexandra Bridge while fitting in with the rest of the downtown core’s architecture. The bridge will carry both vehicular and light-railway transit. The original Alexandra Bridge will be left open as a pedestrian-only bridge, maintain its official status as a Trans Canada Trail route. The box girder bridge design scores 9 for heritage conservation.

7.4.3 Traffic Flow The box girder bridge aims to address the increasing traffic flow needs by adding a completely new bridge specifically for a light-railway transit alongside ordinary vehicular traffic. Pedestrian traffic will continue to be accommodated by repurposing the existing bridge for pedestrian-only traffic. The box girder bridge design scores 9 for traffic flow.

7.4.4 Innovation The box girder bridge will be constructed as a complementary to the main bridge. The simplistic yet strong design lends itself to allow for the focal point to remain on the existing Alexandra Bridge while simultaneously solving both the required traffic and strength demand currently taxing the bridge. Designed with high performance concrete, the deck of the bridge remains thin, but strong, and allows for a reduced overall bridge height, again allowing itself to blend inconspicuously into the background. This would be the first major complementary infrastructure to any existing historical bridge in Canada and would mark a turning point in historical conservation. The box girder design scores 8 for innovation.

7.4.5 Cost The simplistic features of the box girder bridge leads to a lower initial construction cost and lower long-term maintenance costs. Furthermore, since this design is for the complementary bridge option, the cost of demolishing the existing bridge does not need to be considered. It was found that the construction cost was approximately $99 million and the present value maintenance cost was approximately $3.3 million. The net present value of the box girder bridge option was found to be approximately $43.9 million after taking into account the reduction in traffic congestion. Appendix C provides a detailed breakdown of the cost and value of this design option. The box girder design scores 9.6 for its BLCCA.

7.4.6 Construction The construction of the box girder bridge was approximated to take six years based on the construction times of similar bridges such as the Agas-Agas bridge (The Inquirer, 2015), Árpád bridge (Bridges of Budapest, n.d.) and Gazela bridge (Sika, n.d.).

The box girder design scores 10 for construction impact.

7.4.7 Strength Beam bridges such as the box girder bridge are typically the weakest type of bridge because its midspan is not supported and is prone to failure. The strength of this bridge depends on the materials that are being used and the length of the span.

The box girder design scores 8 for excess strength.

7.5 Rehabilitation of Existing Bridge The continued rehabilitation of the existing bridge is the status quo option. It is assumed that the existing bridge will be periodically rehabilitated as it has been in the past.

7.5.1 Design Values Rehabilitating the bridge will allow it to retain all of its original design, including the main cantilever span and the additional two truss spans. This option will best preserve the original heritage and identity of the bridge as the sole bridge between Ottawa and Gatineau at Capital Hill.

7.5.2 Contextual Values Rehabilitating the bridge aims to preserve all of the aspects of the original bridge by performing an extensive rehabilitation program targeted specifically towards strengthening it. Though this design option will not promote any change or historical background, it will preserve all contextual values associated with the bridge. The rehabilitation option scores 10 for heritage conservation.

7.5.3 Traffic Flow Rehabilitation of the exiting bridge does not address any of the traffic flow issues as the rehabilitation program would be targeted towards strengthening the existing superstructure of the

25 bridge. No additional lanes for light-railway transit, ordinary vehicle traffic, or pedestrian traffic will be created. The rehabilitation option does not address traffic concerns and scores 1 for traffic flow.

7.5.4 Innovation Instead of continuing with several small rehabilitation plans, a major rehabilitation program will take place to systematically strengthen the bridge’s deck and truss components to extend its service life. The rehabilitation option scores 1 for innovation.

7.5.5 Cost It was found that in previous years, up to $7 million was invested every 5 years to maintain, repair, and rehabilitate the existing Alexandra Bridge (Public Works and Government Services Canada, 2019). Therefore, the present value of the cost to continue operating the existing Alexandra Bridge was found to be approximately -$24.9 million. Further details on the long-term costs of maintaining the current bridge can be found in Appendix C. The rehabilitation option scores 1 for its BLCCA.

7.5.6 Construction Continued rehabilitations of the existing bridge are expected to take one year each based on the previous rehabilitations that have occurred.

The rehabilitation option scores 1 for construction impacts.

7.5.7 Strength The existing bridge is in immediate need of structural repair. The rehabilitation option scores 1 for excess strength.

8 Weighted Decision Matrix Comparison The design options are compared in a weighted decision matrix based on the analyses and evaluations in the previous section. Table 1 shows the weighted decision matrix.

Table 1. Weighted Decision Matrix

Criteria Weight Continued Cantilever Extradosed Tied- Box Rehabilitation Truss Bridge arch Girder Bridge Bridge Bridge BLCCA 30% 1 10 5.7 8.3 9.6 Heritage 17.5% 10 8 5 5 9 Conservation Innovation 17.5% 1 2.5 7 2.5 10 Construction 15% 1 10 10 7 8 Traffic Flow 12.5% 1 9 9 9 10 Excess 7.5% 1 10 10 10 8 Strength Total 100% 3.25 8.22 7.18 6.73 9.35

The result of the weighted decision matrix shows that the complementary box girder bridge is the best design option with a score of 9.35 based on the evaluated criteria.

9 Conclusions and Recommendations During Phase I of the project, high-level analyses were completed under various weighted categories in order to establish a dominant construction option and bridge design. With a final score of 9.35 out of a possible 10, it was established that the preferred option of choice was the retrofitting of the existing bridge and the construction of an additional complementary bridge. The complementary bridge design was chosen as a box-girder bridge.

Phase II involves the detailed design of the box girder bridge. The Canadian Highway Bridge Design Code, the Concrete Design Handbook, and the Steel Design Handbook will be used in conjunction with structural analysis software to design the members and connections in detail. The bridge foundations will be designed once the superstructure of the bridge is completed. Structural drawings for the plan layout, elevation views, and section cuts for the final proposed detailed design will also be drafted on AutoCAD. Moreover, construction plans will be produced

27 and will contain general construction notes, structural member schedules, and structural drawings.

10 References and Appendices

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APPENDIX A HERITAGE CONSERVATION

In Canada, ‘heritage conservation’ addresses the desires to identify with, protect, and promote both tangible and intangible connections to Canadian historical roots. Three case studies encompassing the fundamental of Canadian heritage conservation practises has been provided as follows: 1. 1875 Demolition of Quebec City’s Quebec Citadel fortification walls – one of the first heritage conservation projects in Canada’s history, the walls were reconstructed with additional evocative contemporary features. Here, the core of the redevelopment project was the picturesque qualities – that the notion of having walls around a city was the identifying cultural trait, and not actually the exact composition (stone) of the walls. 2. 1927 Façadomy of St. Albert’s Log Chapel – half of the building was outright placed, with the core of the structure further encased in a brick shell. 3. 1990 Historical Infill of Halifax’s Waterfront – a conservation project undertaken to promote the culture of the waterfront. Buildings were rehabilitated, gentrified, and renovated into a heritage precinct. These three case studies (further elaborated below) directly correlate with the three principles that Canadian heritage conservation now follows: 1. Design values; 2. Material values; and 3. Contextual values.

Case Study I: Quebec City’s Quebec Citadel Fortification Walls Gail Yudelik and Yvon Desloges’ case study for the Canadian Encylopedia (2011) states that:

“The (Quebec) Citadel has been an active military base since 1920. The Historic Sites and Monuments Board of Canada designated the uneven star-shaped Citadel as a national historic site in 1946 but its importance was recognized much earlier, and it was one of Canada's first heritage conservation projects.

Québec Citadel National Historic Site commemorates a military fortification built by the British from 1820-31 in Québec City. According to a number of 19th-century authors including Charles Dickens, the Citadel, which crowns a 100 m escarpment named Cap-Diamant, made the city the "Gibraltar of North America." It was built when Québec City was Canada's main port, and its purpose was to protect the city from attack from the St Lawrence River below and from the Plains of Abraham to the west. The fortress could also serve as a last refuge for the garrison if the city was captured by an enterprising enemy.

The Citadel has been an active military base since 1920. The Historic Sites and Monuments Board of Canada designated the uneven star-shaped Citadel as a national historic site in 1946 but its importance was recognized much earlier, and it was one of Canada's first heritage conservation projects. The Citadel comprises 4 bastions, or wall projections, and 3 straight

36 curtain walls, all constructed with locally-quarried sandstone. Within its walls are 24 buildings, including one of the 2 official residences of the Governor General (originally occupied by British garrison officers), the Royal 22e Régiment Headquarters (a former hospital), Dalhousie Gate, an officers' mess and a museum. The buildings are constructed mostly of grey cut stone. The fortifications of Québec were one of the reasons why Québec's Historic District was placed on the UNESCO World Heritage Sitelist in 1985. Visitors are allowed in the Citadel but must be accompanied by a guide before entering in through Dalhousie Gate.

The Citadel replaced or incorporated defence works built during the French regime, eg, the western rampart (still in existence opposite the National Assembly). After the Conquest, 1759- 60, the British considered this rampart inadequate but were more concerned with what was happening in Europe than in Lower Canada. With rising tensions between Britain and the United States, the British began to protect their interests in the interior of British North America by implementing a plan developed by Gother Mann in the 1790s. The present ramparts, encircling the Upper Town cliff, and 4 Martello Towers on the Plains of Abraham, were completed before the outbreak of the War of 1812. The Citadel, the principle element of Mann's plan, was not built for it was too large and costly. Its construction began after the war because the British military felt peace was tenuous and Québec City would be the primary goal of any invasion.

Designed by British engineers on a classical model, the Citadel was somewhat anachronistic, given the recent evolution of European military architecture. It was begun in 1820 and completed in 1831, except for a few service buildings which were completed in 1850. The garrison provided most of the labour. Although the Citadel was designed as an arms, munitions and supplies depot as well as a barracks, only part of the 1000-man garrison was lodged there. Soldiers were also billeted in Artillery Park and in the Jesuit Barracks (the site of the present city hall).

After the mid-19th century, improvements in weaponry, particularly the introduction in 1856 of more precise and longer-range rifled artillery, led the British military authorities to modify their defence system substantially. Military fortifications were then located farther from the city centre. During the American Civil War, the threat of an American invasion encouraged the military to construct 3 forts between 1865 and 1871 on the heights of Pointe-Lévis across the river from Québec. None of these structures was ever subject to assault (other than by tourists).

The British military departed Québec in 1871. The Citadel served as headquarters for one of the artillery schools of the Canadian Army and became the headquarters of the Royal 22eRégiment after World War I. Lord Dufferin was the first governor general to make the Citadel a vice-regal residence (1872). It was Dufferin who persuaded local politicians to save the old French walls from destruction although his plan also included some modifications such as extending the Durham Terrace to the Citadel (1879) and constructing a road around the fortress.”

Case Study II: St. Albert’s Log Chapel Canada’s Historical Sites and Places states that:

“The heritage value of the Father Lacombe Church lies in its association with Father Albert Lacombe, its connection to the early establishment of agricultural settlement and religious institutions in the province, and its architectural style.

Father Albert Lacombe was a pioneer missionary in the Northwest Territories. He arrived in present-day Alberta as a secular priest in 1852 and took his vows to join the Missionary Oblates of Mary Immaculate in 1856. Over the decades he spent in the Northwest Territories, Father Lacombe would become a legendary figure throughout a vast region stretching from the Peace River Country south to the Bow River and east from Rocky Mountain House into Saskatchewan. He was known as the "Man with the Good Heart," renowned for his rapport with Metis and Native communities and his ability to negotiate disputes between these groups and Euro- Canadian settlers, government officials, and business interests. His diplomacy was essential in the settlement and development of the West.

In 1861, Father Lacombe and Bishop Alexander Tache selected a site on the north side of the Sturgeon River for a new mission. Tache named it St. Albert after Father Lacombe's patron saint. For the next three to four years, Lacombe was stationed at the mission and helped develop St. Albert into one of Alberta's earliest and most significant agricultural settlements. The Roman Catholic Church was at the heart of the community. In 1871, the Diocese of St. Albert was created and the settlement became the Episcopal See of a vast territory. From St. Albert, Bishop Vital Justin Grandin directed the religious and social work of priests and members of religious orders throughout present-day Alberta.

The first building constructed in St. Albert was the Father Lacombe Church, built in 1861. It is believed to be the oldest building still standing in Alberta. The church typifies the early architecture of Western Canada. The church's design is simple. It was constructed of indigenous materials. The use of squared timber in a post-on-sill construction was a common feature of early settlement structures. This modest building was the spiritual centre of St. Albert, an important community in the early settlement and agricultural development of the province.”

Case Study III: Halifax Waterfront Canada’s Historical Sites and Places states that:

“The Halifax Waterfront Buildings NHSC comprises a group of former stone and wooden warehouses on the waterfront that have been rehabilitated to serve a variety of commercial

38 purposes including offices, shops and restaurants. The designation refers to these large, two-and three-storey rectangular buildings and to the property on which they sit.

The Halifax Waterfront Buildings were designated a National Historic Site of Canada because the site is the most significant pre-Confederation complex of maritime commercial buildings in Canada.

The heritage value of this site resides in the tight grouping of warehouse-type buildings on the waterfront, in their informal, functionally driven designs, and in their relatively heavy and unadorned construction materials and techniques. Construction of this group of buildings began in the early 19th century and proceeded through the century in an ad hoc process of construction, alteration and addition as needs dictated. The number of buildings, their considerable size and durable construction materials speak to the mercantile wealth that supported Haligonian society during the 19th century. The rehabilitation of the buildings in 1972-1973 returned their exteriors to an approximation of their appearance circa 1900, while developing their interiors for new commercial uses and sanitizing their immediate surroundings.”

APPENDIX B FEASIBILITY ANALYSIS

A major challenge restricting the construction of a complementary bridge exists in the surrounding land use and property of the Alexandra Bridge and is two-pronged: 1. restricted by proximity; and 2. restricted by surrounding heritage conservation. Proximity and Association To comfortably associate itself as a complement to the Alexandra Bridge, it is expected that a complementary bridge would be built closer to the Alexandra Bridge and away from Portage Bridge to the south-west and the Macdonald-Cartier Bridge to the north. Furthermore, based on two studies peer-reviewed and published for the International Water Technology Conference (Mowafy, et al., 2001) and the Institution of Civil Engineers it was found that the “minimum distance between two bridges should be no less than 215 times the bridge pier width” (Wang, et al., 2016) to eliminate the cumulative backwater scouring effect for a series of 8 bridges with multiple piers. With the largest pier size on the existing bridge of approximately 6 meters, the minimum distance to a complementary bridge should be no closer than 160 meters. The acceptable locations for a complementary bridge based on association and engineering design are shown in Figure B1, hatched in green on the following page.

Figure B1: Suitable Areas Based on Association and Engineering Design (Google Maps, 2019) Surrounding Land Use Additionally, the existence of several structures and properties along the embankment of the Ottawa River that holds significant local heritage, or has been outright marked as a National Historic Site of Canada, further restrict the suitable locations for a complementary bridge. As a designation by the federal Minister of the Environment as well as the Monuments Board of

Canada (HSMBC) and Parks Canada, the following sites near the Alexandra Bridge enjoys construction protection under Part IV of the Ontario Heritage Act of 1990, section 33, titled Alteration of Property (“Ontario Heritage Act”, 2018): 1. Royal Canadian Mint; 2. Maison des Autres; 3. Major Hill’s Park Building and property parcel; 4. Rideau Canal; 5. Parliament Hill (property parcel); 6. Victoria Bell Tower; 7. Parliament of Canada; 8. East Block; 9. West Block; 10. Confederation Building; The following sites below are considered local assets of considerable cultural significance, and damage or removal should be avoided if possible unless necessary: 11. Jacques-Cartier Park (property parcel) 12. Canadian Museum of History 13. Canadian Children’s Museum 14. National Gallery of Canada 15. Monument Champlain at Nepean Point 16. Justice Building and associated property parcel; 17. Supreme Court of Canada; 18. Library and Archives of Canada. Wherever applicable, the property parcel associated with the specific site in question is to be considered protected under the most applicable stringent considerations. Figure B2 below depicts the various protected sites hatched in red and associated property parcels marked in blue; the marked number beside each site corresponds with the numbering listed above:

Figure B2: Surrounding Land Use (GeoOttawa, 2019; GeoGatineau, 2019; Google Earth, 2019) Due to the positioning of the (1) Royal Canadian Mint and (2) the Maison des Autres, and the close proximity to (14) the National Gallery of Canada and certain infringement on (11) the Jacques-Cartier Park, there is no suitable location to build a complementary bridge to the north- east of the existing bridge. Furthermore, due to the positioning of (5) Parliament Hill, a large

44 portion of the south-west side of the bridge can no longer be considered a suitable building location. Keeping in mind the engineering proximity and heritage constraints, three approximate locations for a complementary bridge were proposed. Figure B3 below depicts the approximate locations for a complementary bridge:

Figure B3: Approximate Locations for Complementary Bridge (Google Earth, 2019)

The approximate locations have been marked and hatched in black and are detailed as follows: 4. Location (1) offers a starting point on Nepean Point, at the same location as the start of the existing bridge. This location will allow the two bridges to share one merge point.

5. Location (2) joins the middle portion between the Parliament Hill buildings and the legal buildings at a lower elevation than the nearby roadwork. It joins Gatineau at a similar elevation near an existing factory plant. 6. Location (3) is similar to location 2 but offers the ability to construct a pier on an existing island in the midsection of the Ottawa river. In the scenario that a complementary bridge design is selected, evaluation of the three locations must be completed.

APPENDIX C COSTS & QUANTITY TAKEOFFS