The topping-out ceremony was held last month for the project, which will form part of the Parisian Macao resort being developed by Sands China, a subsidiary of resorts giant Las Vegas Sands Corporation.
Aurecon has provided full structural engineering consultancy on the job, and helped manage the difficulties of maintaining an authentic design while addressing the challenges caused by extreme weather, a congested construction site, and the anticipated high number of visitors.
At the project’s outset, Aurecon provided a model of the tower using Revit software, which allowed the team to represent the complicated design connections in 3D for easier detection of any potential challenges or clashes.
“The key to recreating this iconic landmark has been strong team work and the close collaboration between the design and construction teams,” said Dr Alecs Chong, Aurecon’s project leader on the Macau Eiffel Tower.
Chong said that the close co-operation between the design and construction teams started at the earliest stages of the project, and has delivered efficiency improvements from the beginning.
“The original structural performance criteria for this project were specified at an early stage and were largely based on the criteria commonly used for conventional office or residential buildings,” he said. “However, given that the tower behaves as a slender, open-lattice structure, some of the serviceability performance criteria were too conservative and after consultation with stakeholders, these were subsequently relaxed. So, clear communication between the design and construction teams, supported with sound technical evidence, delivered an outcome that would allow the design team maximum flexibility.”
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Among the biggest challenges for the design team was addressing the issue of typhoons, which occur seasonally in Macau. In particular, the design team had to ensure it made the correct critical wind loading calculations for the tower in the event of a direct hit from a typhoon.
A further challenge was accounting for the very high number of visitors the attraction is likely to draw. In particular, the designers focused on the footbridge that will connect the tower with an adjacent casino complex. “As a result, we adopted an acceleration-based vibration assessment method to review the bridge’s design taking into account the loading caused by crowd walking,” said Chong. “We used superposition to look at responses caused by various vibration modes to get to an overall vibration response, which we then established was within acceptable human comfort levels.”
Outside of the challenges directly linked to the tower’s design, Aurecon and its partners also had to contend with practical difficulties related to the construction work. Specifically, how to get the large steel sections needed for the tower’s construction to the site and, once there, how to assemble them.
“The port of Macau is neither large enough nor deep enough for the vessels that would normally deliver the oversized steel sections needed,” says Dr Chong. “As a result, the job had to request shallow-hulled vessels, but this limited delivery capacity. This, in turn, meant we had to plan the size of the delivery racks, to maximise delivery capacity and minimise delivery costs, which were estimated as being anything up to a quarter of the overall material cost.”
There was also a challenge in selecting the tower crane. “On a traditional concrete building the tower crane is attached to the construction as it climbs, offering lateral rigidity so the crane can be raised higher and higher,” he says. “But because the replica Eiffel Tower is such a slender structure, the support for a regular tower crane is not there.”
The solution came in the form of a luffing jib crane, which can articulate its jib between the horizontal and near vertical angles. Using such a crane, and fitting it with a shorter jib, meant less of the lifting force was distributed laterally and more was directed down the crane’s mast.
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