Clients / MTO 2001-0022

Location: QEW – Hwy 420 Niagara Falls
Description: Highway and Bridge Rehabilitations, Construction of New Bridges

7- Bridge 7 - New ConstructionThis project included grading, drainage and granular base, hot mix paving, structure rehabilitation, replacement and illumination. The structural components of the project included the complete demolition of three existing bridges, the new construction of two pre-cast girder bridges, a rigid frame bridge, and a complete bridge deck removal and replacement with a new post tensioned deck and six additional post tensioned bridge deck rehabilitations.

This project included complete jacking design and procedures and details for four different size post tensioned bridges. Design solutions included three different types of support systems using 100T hydraulic jacks to fit the actual site condition. For one of the bridges, the design included supports with different heights of structural steel columns to transfer the jacking load directly to the footings. Each individual column had to be checked for its compression capacity with respect to the slenderness ratio. He also designed temporary support for the jacks utilizing heavy-duty brackets, checking the shear and tension capacity of brackets as well as the pin capacities. The third system was with the installation of different size and shape recesses on the face of the abutment. The designs for these bridges included jacking and repair procedures for all different rehabilitation methods.

One of the post-tensioned bridges involved the rehabilitation of the deck, ballast walls, barrier walls, and expansion joint. This part of the project was particularly challenging because the original design provided by the MTO, to perform localized structure rehabilitation, was amended by a change proposal to completely reconstruct the bridge superstructure. The change proposal involved bridge deck demolition saving the existing four pier columns and abutment substructure. The replacement deck consisted of new post-tensioned bridge deck construction.

During these operations, several design calculations for structural steel falsework with an 18.0m span for a 1.2m thick concrete deck including mudsill arrangement for the shoring system between the pier columns and the abutments were required and completed. The design included detailed deflection calculations for the beams to maintain the necessary clearance under the falsework and to determine the required camber adjustment on the beams.

Other design included temporary roadway protection designs for Highway 420 and for the QEW extension as well. The roadway protection at highway 420 had 8 driven piles with a wood lagging system parallel with the center pier footing – providing a safe working area as well as the required support for the highway. The other side of the road, the roadway protection had three drilled piles with a cast in place concrete footing. Both systems were monitored for any movement with survey equipment.

Also included were various types of formwork design for barrier walls on post tension bridges, and pre-cast girder bridges and on wing walls.  Including calculations for formwork and falsework for pre-cast girder bridges. He prepared the design calculations for sizing and spacing of the structural members to support the applied loads (loading due to construction activities, dead loads of materials, and loading due to the new concrete deck).