Dossier: the 28 ‘crumble-bridges’ of Flanders
Flemish government is following up 28 of its 2.618 bridges with priority because they need to be repaired or replaced. Knack magazine investigated the list of ‘crumble-bridges’ and found out five of them are on the list for 20 years already.
The problem bridges are listed in the Lijst van de Prioritaire Kunstwerken (a list of priority infrastructures) summing up meticulously all failings. These are numerous: severe concrete damage, corrosion of reinforcements, sagging of the bridge deck, cables rusting away, overloading due to renovation works, general bad condition,…
‘Dangerous bridges’ is not the right description, engineer Paul Meekels, head of the department Examination of Concrete and Steel and expert on bridge safety of the Flemish government says. “All bridges on the list need priority structural repairs. In the mean time they’re being monitored closely. If we’re afraid there is even a minor risk the bridge would collapse, it will be demolished.
“On March 18th 1992 for the last time a bridge in Flanders collapsed: the one over the river Scheldt in Melle”, Meekels says. “Unfortunately a truck was driving over the bridge when it happend. The driver was killed. This scenario won’t repeat itself because we are watching all bridges closely.”
Most of the 2.618 Flemish bridges are in good condition. Depending on the risk, all bridges are inspected very thoroughly and all failings are listed, every 3, 4 or 5 years. Bridges are designed to last 100 years. But in practice, they only last 70 to 80 years, the Flemish government noticed. Steel bridges are prone to metal fatigue, concrete bridges suffer from all kinds of concrete cancer.
The list with problem bridges is actualized every month and categorized in 1st (urgent) and second priority. 16 of the 28 bridges are on the list for more then 10 years. Five of them even 20 years. The latter are all over the E40 in Ghent, Wetteren and Zwijnaarde. “That’s the reason why”, Meekels says. “It is very difficult to work on them without causing a traffic chaos”. By the end of April works on the bridge over the Tij in Zwijnaarde will start.
Knack asked Meekels to calculate the average time bridges were on the list in the last ten years. 58 bridges are removed from the list after repairs. The most urgent ones after 5,5 years, bridges with second priority had to wait nearly 10 years.
No need to panic
Experts of the University of Leuven say there is no need to panic. “Some bridges are in bad condition and waiting for 20 years to repair them is maybe too long”, says Luc Taerwe. “But it is not because the bridge shows some cracks, it is going to collapse. Concrete constructions are very robust in this field and corrosion and other processes are very slow”.
Minister of Mobility Ben Weyts (N-VA) says 2 bridges are being renovated, 7 others are planned in already and for 14 others a timing is prepared. Three bridges are part of larger projects and 1 bridge is classified and requires a phased approach. Weyts decided to raise the budget for the bridges to 16 million in 2017, 36 million in 2018 and 55 million in 2019. Meekels estimates the total cost of renovating the bridges is 170 to 200 million.
According to Wim Moesen, professor governmental finances at the KU Leuven, says the way the problem bridges are tackled are typical for Belgian politicians in the past refraining from investing in the infrastructure. “Belgium always wanted to be a logistic hub, but now we’re loosing that trump card”.