The construction of Brussels' new metro line 3 has been complicated for several months, as a 120-metre-long tunnel must be dug underneath the iconic Palais du Midi building along Boulevard Lemonnier. But as the underground is not ideal, substantial improvements have to be made.
The tunnel – which should have been finished by now – is needed to connect the planned 'Toots Thielemans' metro station with the existing 'Anneessens' one. However, it would pass through the old bed of the Senne river, where the still soggy soil poses a lot of problems for construction, La Libre reports.
The supporting pillars that are supposed to form the tunnel walls, for example, do not go straight into the wet ground but at an angle – meaning they do not form a watertight seal. Since mid-2021, works have therefore been halted.
"Two options for this problem are now on the table," Brieuc de Meeûs, CEO of Brussels public transport company STIB, told Bruzz.
An extra €170 million?
The first one is to continue with the same technique, but using heaving posts. "However, the consortium is asking an extra €170 million for this, which is about as much as what the entire stretch between Gare du Midi and Anneessens costs," said De Meeûs.
The deadline would then be pushed back by eight years, which is "unacceptable" he added. "Continue using the same technology is certainly an option for us, but only at a reasonable price and timing."
A second option would be to partially demolish the Palais du Midi, De Meeûs added. "The facades can remain, but the roof of the eastern part (with the sports hall) must be removed. We can then drill wells in the middle of the building, fill them with reinforced concrete and excavate the tunnel in between."
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What this option would cost and how long it would take is not yet known, but as there is a possibility that a building permit must be requested, De Meeûs fears that this would also take a lot of time. Importantly, the intention is to rebuild the Palais du Midi afterwards.
The Palais dates from 1880 and is listed in the inventory of the Brussels architectural heritage, but is not protected. The building also houses the francophone college Francisco Ferrer, which may have to move during the works.
For De Meeûs, there is no preferred scenario yet. "We are waiting for a clear price and plan."