SMi took part in one of the biggest challenges of the Turcot project
The KPH Turcot team performed the dismantling of the railway tunnel located under Sainte-Anne-de-Bellevue Boulevard (Route 138) around the access ramps to highway 20. The dismantling of this tunnel was one of the biggest challenges facing the demolition team since the 4 Canadian National (CN) railway tracks had to remain operational at all times.
Credit: KPH Turcot
Mandated by the Ministry of Transport of Quebec and KPH Turcot as the independent certifying body, the team of specialists from SMi was responsible for issuing design work certificates of the dismantling. During construction, SMi / Arup will conduct daily inspections to ensure compliance with the technical contract requirements in relation to the certificates issued previously. Subsequently, SMi / Arup will issue certificates specifying the degree of progress for supplier’s payment purposes.
Out of the three methods of execution presented to the KPH Turcot team, it is the gantry crane lifting method that was retained due to the fact that this method limits the impact of the work on the residents. Moreover, this method is the one that presented the fewest risks to the CN.
Credit: The S.M. Group International Inc./Arup
Briefly described, the work consists of cutting the tunnel in several sections, which will be moved outside of the railway area using the gantry cranes to then dismantle the sections in a work area south-east of the tunnel, away from the residential area.
The first step has already been completed and consisted of removing the 13 box girders of the east part of the tunnel while the crane is positioned on the south side of the tunnel. The second step is the dismantling of the tunnel arches which were separated from the foundation elements using a diamond wire saw. To accomplish this, holes were perforated under each arch to allow the installation of the anchors of the lifting system.
A self-propelled transport module will be mobilized and then assembled in order to be used as a gantry crane.
In all, 9 sections, with a length of 11,3 meters each, including the arches and the walls, will be moved to be dismantled on the work area. The total weight of one section is roughly 1100 metric tons which means that a grand total of 4500 cubic meters of concrete will be demolished and recycled as road foundation materials.
A demolition challenge which, with the expertise of SMi’s specialists, was overcome while still meeting all the conformities of the mandatory technical requirements.