Mackay Pier

Repair the Mackay Pier and the Concorde Bridge by jacking structures in place, securing them, then forming the repairs — all on the same site and within the same season.

The challenge was the breadth of the scope. A single mandate covered the jacking of pier 2 and axis 6, the passive shoring that takes over from the jacks, the securing of the pier, formwork for columns, parapets and architectural walls, and the traffic surcharge allowed during the work. Each part set the conditions for the others.

Jacking of pier 2 — Transfer beams at axes A, B and C, anchored by plates into the existing concrete, with a lateral stabilization device at axis B; the design was reworked over three successive revisions to optimize the anchorages.

Jacking of axis 6 — Lifting structure and sizing of the ground bearing pads, based on the bearing capacity established for each location.

Passive shoring — Passive shores taking over from the lifting structure during the work.

Securing of pier 2 — Anchored horizontal and vertical beams, brackets and point anchor plates.

Formwork — Steel circular columns at axis 6, pier 2, parapets and architectural walls, various concrete repairs and the axis Y beam: form layouts, concrete pressures and sizing of walers and joists.

Traffic surcharge — Verification of girder capacity under a 3 kPa construction surcharge, according to the phasing and the demolition work, based on the girder marking survey for axes 0 to 12.

Temporary guardrails — Verification of the guardrails in service on site.

Certification — Certificates of conformity for the jacking of axis 6 and pier 2.

A project like this one does not break down into specialties: jacking sets the conditions for the formwork, the formwork sets the allowable surcharge, and the surcharge sets the phasing.

Twelve mandates ran in parallel on the same structure, with the same people around the table. That is what a team covering lifting, shoring and formwork makes possible: one point of contact, and interfaces that do not get lost between two firms.

Thanks to ConCreate.