SNC-LAVALIN with: B&B CONTRACTING LTD. DELCAN CORPORATION EBA ENGINEERING CONSULTANTS LTD. FRASER RIVER PILE & DREDGE LIMITED PARTNERSHIP FREYSSINET CANADA LIMITEÉ GEORGE THIRD & SONS LTD. INTERNATIONAL BRIDGE TECHNOLOGIES, INC. LOWER MAINLAND STEEL LIMITED PARTNERSHIP MANSONVILLE PLASTICS (BC) LTD SHANNON WILSON, INC. STANTEC TRANS-WESTERN ELECTRICAL LTD. SNC-LAVALIN COAST MERIDIAN OVERPASS PROJECT PROJECT HIGHLIGHTS Prior to the construction of the Coast Meridian Overpass, span. The team used multiple cable adjustments during the City of Port Coquitlam in British Columbia was the construction process and, to minimize additional divided by Lougheed Highway – a major arterial in loading, placed a sliding deviator block over top of the Metro Vancouver – and Canadian Pacifi c (CP) Rail’s lead pylon for the temporary cable. largest active rail yard in western Canada. The City responded to this need for improved inter-city mobility An Integrated Design-Build Team and accessibility by developing a conceptual design Managing the project’s major bridge and roadway for the Coast Meridian Overpass. Envisioned to relieve construction activities required a design-build team with traffi c congestion, unite the two sides of the city, and a solutions-oriented approach. Together with the City, connect Port Coquitlam with other major regional SLCP implemented comprehensive traffi c management, transportation networks, the Coast Meridian Overpass safety, public communications, and environmental plans was awarded as a design-build project to SNC-Lavalin that minimized impacts to residents and businesses, Constructors (Pacifi c) Inc. SNC-Lavalin Constructors and maintained the project’s overall schedule. The Coast (Pacifi c) Inc. (SLCP) submitted the lowest qualifying bid, Meridian Overpass Design-Build Project was delivered which included a design for a 580-m, hybrid twin box- on time and on budget to the City of Port Coquitlam in girder, cable-stayed bridge with four traffi c lanes and March of 2010. With the Coast Meridian Overpass in facilities for cyclists and pedestrians. place, Port Coquitlam residents enjoy greater mobility between the two sides of the city, and access to other key A Unique Design transportation routes, including the Mary Hill Bypass, SLCP’s integrated design and construction team Trans-Canada Highway No. 1, and the future Evergreen developed a design process that synthesized Line extension. construction and fabrication methods. Limited by pre-defi ned pier locations, access to the rail yard, and an active seismic zone, the Coast Meridian Overpass SNC-LAVALIN used a single line of columns and large-diameter piles with: to navigate these constraints. The unique cable-stayed B&B CONTRACTING LTD. and steel superstructure lightened the overall structure DELCAN CORPORATION and reduced its depth by nearly 2 m. Building on the EBA ENGINEERING CONSULTANTS LTD. advantages of a cable-stayed design, the team used a permanent cable to minimize defl ection during the FRASER RIVER PILE & DREDGE LIMITED PART- longest push-launch process successfully attempted in NERSHIP North America. FREYSSINET CANADA LIMITEÉ GEORGE THIRD & SONS LTD. An Achievement in Construction INTERNATIONAL BRIDGE TECHNOLOGIES, INC. The project’s major challenge was push-launching a LOWER MAINLAND STEEL LIMITED PARTNERSHIP 580-m bridge over an active rail yard. The push-launch construction method succeeded in launching six spans MANSONVILLE PLASTICS (BC) LTD over the CP rail yard and one over Lougheed Highway. A SHANNON WILSON, INC. hydraulic jack pushed the span structures over the south STANTEC embankment on rollers. TRANS-WESTERN ELECTRICAL LTD. Cable supports were carried forward to the erection scheme, where the permanent stay cable and a temporary pair of cables supported the leading edge of the launched CANADIAN CONSULTING ENGINEERING AWARDS 2011 Page 1 Project Description SNC-LAVALIN COAST MERIDIAN OVERPASS PROJECT OBJECTIVES When the City of Port Coquitlam developed a conceptual overpass subsequently became one of TransLink’s major design for a structure spanning an active Canadian Pacifi c road priorities in its 2005-2007 plan. (CP) Rail yard, its goals were unity and accessibility. To achieve these objectives, the City set an aggressive Before the Coast Meridian Overpass, north and south budget and schedule for the Coast Meridian Overpass, Port Coquitlam was divided in two; Lougheed Highway resulting in the largest civil works project the City had and CP Rail’s largest yard in Western Canada were ever considered. Had the bids from the private sector sandwiched between two communities: a residential been above the City’s estimates, the project would have area and an industrial park. Inter-city movement was likely been stalled. The City also needed to negotiate limited to two crossings to the east and west of the yard. an arrangement with CP Rail that would minimize The concept of uniting the two sides of the city was impacts on their operations, despite creating only a short not new. Discussions about crossing the rail yard construction window to complete the work. began as early as 1913 and were re-acknowledged in After reaching an agreement with CP Rail to facilitate regional plans in the 1980s and community and master construction and after fi nalizing a cost-sharing transportation plans in the early 2000s. A third yard partnership with TransLink, the City eventually awarded crossing was deemed a critical access link and necessary the design-build contract to SNC-Lavalin Constructors to improving emergency response times, promoting (Pacifi c) Inc. (SLCP). As the proponent with the lowest multi-modal transportation options, and reducing air qualifying bid, SLCP was given the complex task to pollution caused by idling vehicles. Nor was the City design and build an overpass in and over a yard handling alone in realizing the benefi t of an overpass. TransLink, 3,000 to 3,500 rail cars – including the West Coast Express Metro Vancouver’s transportation authority, recognized commuter rail – each day. As well, all major road work that an overpass would alleviate traffi c congestion on activities had to minimize disruption to local traffi c, Lougheed Highway and would be a key component businesses, and residences during construction. to the region’s growing transportation network; the 2 1. This pre-overpass aerial photo demonstrates how the rail yard divided the community, with only Shaughnessy Street and Mary Hill Bypass as access points. The dashed line indicates the location of the new overpass. 2. The Coast Meridian Overpass expands the road network of the city and provides 1 another connection to the soon-to-be twinned Port Mann Bridge river crossing. CANADIAN CONSULTING ENGINEERING AWARDS 2011 Page 2 SNC-LAVALIN COAST MERIDIAN OVERPASS PROJECT SOLUTIONS AND ACHIEVEMENTS The Challenge The Solution: A Unique, Cable-Stay Design The project, strong in its potential to offer lasting The bid documents included an original design concept benefi ts to the City and surrounding region, came with of the Coast Meridian Overpass as a conventional, steel extraordinary site, construction, and logistic challenges: girder bridge with a 5-m depth, fi ve I-girders abreast, and a composite reinforced concrete deck. But with the pre- • Limited pier spacing. Because of the rail yard determined pier spacing agreed upon by the City and density and congestion with over 50 rail tracks, CP Rail, the limited ground access and vertical clearance the locations available to place piers were limited requirement, as well as the extremely limited footprint and pre-defi ned. This created a long, uneven span for each pier, the original design proved challenging. length arrangement (approximately 102 m-125 m-110 m-125 m-72 m-46 m), which did not give the During initial studies, the design-build team developed structure an optimal load distribution. three distinct concepts. First, the base concept was refi ned to four I-girders instead of fi ve. A fi ve-girder design, • Bending capacity. The footprint for the piers, tucked under various scenarios, proved diffi cult to launch and in between railcars envelopes, would only allow required higher steel quantities. However, the team a single line of piers and piles, compromising the found that even four girders resulted in an impractical bending capacity of the bents. erection process. • Tight vertical clearance. The project requirements Next, the design-build team considered a twin box girder stipulated a minimum vertical clearance of 7.05 m concept that utilized post-tensioning on the longer spans. above the track top-of-rail to accommodate double In order to be feasible, a launched structure requires a stacked railcars. section with constant depth; post-tensioning would allow • Limited site access. Due to rail yard activity, it extra capacity over the piers, whereas a deeper section was not possible to work from the ground or would have been present. While comparable in depth to to provide temporary supports. This forced the design-build team to launch the structure. With the span layout and vertical clearance restrictions, a special structure was required. • Soil and seismic considerations. Located in an active seismic zone, the site’s soil conditions included a deep 20- to 30-metre-deep layer of soft materials with little lateral capacity. 1. The fi xed locations for piers created spans with different load distributions. 1 CANADIAN CONSULTING ENGINEERING AWARDS 2011 Page 3 SNC-LAVALIN COAST MERIDIAN OVERPASS PROJECT the base concept from the City, this option required large An Alternate Design Concept structural elements and revealed logistical challenges SLCP’s integrated design-build team developed a bridge during construction. design for a steel, twin box girder structure with a single The third option saw a single, pre-cast, segmental, plane of stay cables. The structure measured out at 580 concrete box girder with extradosed cables. Constructed m, with four lanes of traffi c and facilities for cyclists and by an overhead truss, this bridge would eliminate the pedestrians. Overall, the design: need to launch the bridge and would reduce contractor • Resulted in a shallower (by 2 m) and lighter risk.