OWNER  Kiewit Flatiron GP

COMPLETED  June 2012



The Fraser Heights Wetlands Viaduct is an integral component of the new South Fraser Perimeter Road and Port Mann Highway 1 projects which connect Deltaport to the Golden Ears Bridge and Highway 1 corridor.


GIG completed this very unique design-build segment of the overall Port Mann Highway 1 Project. This $17 million bridge consists of two 500m long separated parallel structures crossing a very environmentally sensitive wetland eco-system. Heavy equipment was not permitted in the bridge right of way or surrounding wetlands area; therefore some innovative solutions had to be found in order to build the structures.




This project was built using a “top down” construction method; meaning that the structure itself was used to support construction loads with no heavy equipment on the ground. The original design of the bridge accounted for these extremely large loads which meant that the structure was significantly overdesigned for the final service design loads imposed on it.  During the design optimization phase of the project, GIG developed a construction methodology solution which would remove construction loads from the permanent structure thus streamlining the design and reducing construction costs significantly.


The work involved driving 610mm diameter pipe piles to depths in excess of 30m, filling the piles with concrete and reinforcing steel, installing prefabricated structural steel pile caps and girders and placing of precast concrete deck panels for the finished roadway. Work on both parallel structures was carried out from the North structure only. The work also included construction of abutments and end fills incorporating MSE retaining walls. Due to the environmental red zone classification of the site, all clearing activities were done by hand work using small tools and light equipment only. A detailed Quality Management Plan, which had to align with the very strict overall Quality Plan for PMH1 Project, was implemented on the project. 


The Gateway Infrastructure Group was contracted to:

  • Constructing a 70m long by 28m wide rail bridge to accommodate 6 new railway tracks across Lynn Creek

  • Constructing a 28m long extension of the Brooksbank Ave Underpass including extensive cast-in-place retaining walls for the underpass approaches

  • Providing Fisheries compensation by the creating new riparian and instream habitat

  • Relocating and expanding District of North Vancouver Parks facilities including additional hiking trails and parking for Harbourview Park

  • Relocating and upgrading Port Metro Vancouver and municipal underground services

  • Installing sheetpile and anchor piling support of adjacent existing rail bridge

  • Dewatering

  • Constructing a cofferdam and excavating for abutment construction

  • Stabilizing river bank

LOCATION  North Vancouver, BC 

OWNER   Port Metro Vancouver

COMPLETED  January 2012

VALUE  $16.3M


As part of improvements to rail capacity in the North Shore trade area, six track widening of the existing railway bridge over Lynn Creek and the existing rail/road grade separation at Brooksbank Avenue was required.  Port Metro Vancouver (PMV) coordinated this multi stakeholder infrastructure improvement project, with GIG being awarded the contract through a combined prequalification and competitive bid process.


The multi discipline nature of the Lynn Creek/Brooksbank Project perfectly suited GIG’s skill set.  The GIG partners provided the expertise to complete the major construction elements:  all cofferdams, dewatering, foundations, structural concrete, bridge deck precast, earthworks, underground utilities, environmental protection, earthworks and road construction.


The GIG project management team successfully scheduled and coordinated this work with that of specialty contractors to ensure completion of the  project on time and on budget.

Extensive construction staging was required to provide continuous access to port facilities and local businesses.  By first constructing the new railway bridge over Lynn Creek, the railway bridge was temporarily used as a vehicle bridge, as part of an elaborate detour, allowing for an extended closure of Brooksbank Avenue for the underpass construction.




LOCATION  Vancouver to Langley, BC 

OWNER   Kiewit Flatiron GP

COMPLETED  June   2012



Since the beginning of construction in 2009, GIG was involved as a preferred subcontractor to the Kiewit Flatiron GP (KFGP) Design-Build team, for the replacement of the original Port Mann Bridge and upgrading of 37km of Highway 1 from Vancouver to Langley.  Primary activities included the construction of replacement overpass structures across Highway 1 at 160th Street and 104th Ave in Surrey.  Additionally, GIG has provided utility protection and relocation services throughout the Port Mann/Highway 1 (“PMH1”) corridor, including relocation of City of Surrey trunk sanitary sewers and watermains for the environmentally sensitive 176th Street and 104th Avenue intersection reconstruction.


As a provincial design-build project, the Project was required to develop and administer a comprehensive Quality Management Plan covering all aspects of design and construction.  GIG was required to adhere to this plan and provide all documentation and third party QC testing to satisfy project requirements.


In order to keep the existing overpass structures open to traffic until completion of the new overpasses, the new structures were designed to be built immediately adjacent to the old. This required development of site specific temporary shoring to support the 50 year old overpasses while bridge end fills and abutments were constructed for the new structures, arm’s length from the existing.


The project required construction of MSE walls for abutment support immediately next to an operating freeway. This required coordination of traffic staging and detours to allow for safe placement of precast bridge deck girder over top of existing highway.



Project Innovations

  • combining various temporary retaining wall designs to allow for protection and support of existing structures during construction

  • use of custom concrete and galvanized steel split casings to protect in service municipal utilities to allow for highway widening

  • staged deep foundation peat excavation and replacement with light weight fills to allow for replacement of municipal trunk utilities under roadways avoiding the cost of piled foundation


GIG was required to comply with the stringent project-wide Environmental Management Plan, specifically sediment control, and control and treatment of concrete wash.  The two overpass structures bookend a fisheries watercourse which required regular monitoring and protection. Further, GIG adhered to the PMH1 safety program developed for the project by KFGP to specifically address the safety concerns of working in close proximity to high volume traffic.