Civils Demolition

PHOTO: DELSAN-AIM

DELSAN-AIM

COUNTRY Canada

PROJECT Champlain Bridge Deconstruction

CLIENT Jacques Cartier and Champlain Bridges Inc

The Champlain Bridge spanned the St Lawrence River in Montreal, measuring 3,441 m long from abutment to abutment. It was decommissioned in 2019 after a new bridge was opened and Delsan-AIM and its partners were contracted to dismantle it.

The old structure presented significant engineering challenges due to its massive size, environmentally sensitive location, and the presence of a vital shipping channel and a major highway below.

The contractor removed 36, 2,000-t concrete spans and the 2,200-t main span section using a strand-jack system on a barge that was positioned 33 m below it. Delsan-AIM also performed the mechanical demolition of an overland section that required 20 excavators and a 50-hour closure of a major highway that was situated below.

The three-and-a-half-year project achieved a recycling and materials reuse rate of 96%. ■

PHOTO: DEMEX

DEMEX

COUNTRY Australia

PROJECT Pacific Motorway M1 Palm Beach to Tugun Upgrade

CLIENT Seymour Whyte Construction

Demex was contracted to demolish seven bridges in a 5-km stretch of the Pacific Motorway (M1) in Australia’s Gold Coast over 14 months.

A mechanical deconstruction approach was adopted. Minimising disruption to road users posed logistical challenges as all works had to be staged at night, with the site cleaned and validated safe by an independent structural engineer, by the start of morning traffic between 3.30 and 5.00am.

The works were complicated by the nature of the working hours and the strict deadline for reopening each morning. Additionally, when expanded polystyrene was identified in core bridge decking, safe removal processes had to be developed on the job.

Project planning required a flexible, solutions-oriented approach to overcome the engineering challenges the project presented due to the variability in bridge design and location. ■

PHOTO: THOMPSONS OF PRUDHOE

THOMPSONS OF PRUDHOE

COUNTRY United Kingdom

PROJECT A1 Highway Improvement Scheme

CLIENT Costain

Thompsons of Prudhoe was contracted to design and deliver the safe removal of end beams, edge beams, and coping beams from multiple highway bridges, facilitating future extensions of existing bridge decks as part of a major road widening scheme in northeast England.

The critical challenge was to preserve the longitudinal bars in the retained portion of each bridge deck, ensuring their reuse in the new, extended bridge decks.

The works required highway closures, including full and lane closures, with a significant amount of the works being carried out at night.

Through successful collaboration with the principal contractor and a network of trusted specialist subcontractors to safely and effectively remove the bridge beams and perform associated works, all tasks were completed ahead of schedule with zero accidents or incidents. ■

PHOTO: DESPE

DESPE

COUNTRY Italy

PROJECT Charmaix Viaduct

CLIENT Societe Francais du Tunnel Routter du Frejus

Despe’s demolition of the viaduct, which was located in mountainous terrain next to another viaduct, included the creation of access roads for haulage trucks, manoeuvring areas and a lay-by for the assembly and operation of a 1,900-tonne crane, as well as the creation of plotting areas for the bulkiest parts of the Liebherr 11350 crane.

Despe used long booms, diamond disc cutting and wire cutting, and performed 16 consecutive lifts of over 210 tonnes each, which combined lifting with two cranes. ■

PHOTO: GRUPO MITRE

GRUPO MITRE

COUNTRY Argentina

PROJECT Cementerio Stage 2

CLIENT Gobierno de la Ciudad de Buenos Aires

Located in a Buenos Aires neighbourhood with high levels of criminal activity, the Flores Cemetery required crucial restoration due to corrosion and structural damage threatening its integrity.

The location meant the contractor's team was subject to occasional armed confrontations and a hostile atmosphere.

Following a partial collapse, Grupo Mitre preformed urgent demolition, reinforcement and waterproofing of the cemetery’s slabs.

Diagnostics, 3D structural scans and BIM technology ensured optimal work methods that would preserve the site's history. ■