Pattullo Bridge, Surrey, Canada

Description

Crossing the Fraser River, the Pattullo Bridge is a key connection between New Westminster and Surrey in British Columbia. The bridge, which is more than 80 years old and does not meet modern design standards, is being replaced with a new bridge that will improve safety and reliability for drivers, cyclists, and walkers, as well as goods movement.

ULMA solution

ULMA participated in this project by offering its concrete forming systems: Special MK Truss, ENKOFORM HMK, and VR Tables. 

MK Truss:

• Two cast-in-situ concrete cross beams are connecting the Pattullo Bridge tower legs at +39.00m and +107.00m elevations.
• The lower cross beam is 7.00m wide, 5.50m high and 31.00m long.
• The upper cross beam is 5.50m wide, 6.50m high and 28.00m long.
•  A special MK Truss is designed to carry these extreme loads and transfer them to the tower legs.
• Most of the items used in the design are part of the regular MK Structures material family which allows them to be used for future formwork applications.

ENKOFORM HMK:

• For the first and second stages of pouring, formwork for the bottom slab and the exterior wall of the cross beams are designed to be assembled as a single unit on the ground and lifted to their location on the MK Truss.
• Single unit formwork is eliminating the need for alignment and the related safety concerns while working at heights.
• MK-120 steel walers which create the MK Truss are being used again for the formwork with VM-20 timber beams as the support for the plywood surface.

VR Tables:

•  For the last stage of pouring, VR Tables are designed to provide formwork for a top slab of the cross beams.
•  Assembly will be done on the ground and will be lifted to their location without the need for any adjustments afterward.
• ALUPROP is providing adequate working space under the formwork in a tight area by having fewer components than regular shoring systems.   

The project is being carried out in four Phases:

• Phase 1: MK Truss and formwork assembly for Lower Cross Beam at +39.00m elevation.
• Phase 2: Dismantling and lowering of the MK Truss and formwork together from Lower Cross Beam using strand jacks.
• Phase 3: MK Truss and formwork assembly for Upper Cross Beam at +107.00m elevation.
• Phase 4: Dismantling and lowering of the MK Truss and formwork together from Upper Cross Beam using strand jacks.