Renewable Matter # 23-24 / September-October

Recommendations After the Collapse of a Bridge

by Federico Pedrocchi

I remember a meeting amongst architects in the early 90s where we addressed the news that reinforced concrete was actually subject to deterioration. It signalled the end of a powerful paradigm. It would be interesting to collect all the times in which “reinforced concrete” has been used to describe something indestructible. Not to mention bunkers, a true synonym of that which can be considered bomb proof. On the contrary, reinforced concrete crumbles. And, the problem is that we put concrete everywhere; with understandable confidence.

In light of this, people should react differently to a tragedy such as that of Genoa’s Morandi Bridge and should be more careful when making statements. It is certainly not appropriate to express positive remarks on the indications that may come from a calamity where the death toll has risen to 43 people and is now creating huge problems for the city. But, within a framework of a quiet confidentiality, commentators, ministers, mayors, and CEOs – as far as I understand and thanks to a few conversations that I have had in the weeks following the collapse – have to accept with no hesitation that performing the necessary checks for maintenance on that structure was essentially impossible because of the way it was built. And this approach should be extended to reflections on many other structures, so as not to trivialise the topic of maintenance. Then, we can discuss the implementation of precautionary measures which, it goes without saying, would have led to a single possible outcome: closing the bridge. 

Easier said than done.

Such smart caution would also have played a key role in this, as well as many other, emergencies. Namely, providing the general public with a more advanced and reflective point of view, away from today’s rampant irrational solutionism, so as to pave the way for a season of sensible planning; devoted to securing Italy’s infrastructure, historical heritage and environmental conservation. An inescapable transversality for a serious and forward-looking plan. 

In order to design new structures, for instance, it is necessary to employ a series of new materials whose performance has already been put under considerable stress during very reliable tests; materials that can withstand heavy loads whilst being extremely light. The Morandi Bridge’s weight was certainly a factor in its collapse, as is the case with any structure. A leaning Tower of Pisa made of graphene would not have leant, although it would not have been as beautiful. There are also interesting experiments where a mix of chipped plastic and cement are providing excellent results.

As for sensors, they can undoubtedly act as a very useful tool, but we should not ascribe them with miraculous qualities. First, the effectiveness of a sensor is strictly linked to the way a structure is built. If components sunk into a cement shell (such as with the Morandi Bridge) have to be monitored, sensors are of little to no use. Even what “breakage” to monitor is a variable that must be taken into consideration. There are crashes that occur after lots of little movements and others where the collapse is sudden, where there is little that can be done.

Having said this, we can certainly carry out inspections and interventions on all existing structures, and as always assessing the potential of new materials.

With regards to inspections, drones do come into play because they allow for very close inspections and produce footage that can be consulted at a later stage. I would like to point out, though, that extreme care is necessary. Flying a drone effectively is nothing like playing videogames. A drone pilot is able to fly the aircraft in any direction only if he/she has sufficient flight hours’ worth of experience. If this is not kept in mind, certain inspections may run the risk of being considered non viable, whereas they could be carried out with more experienced pilots. Italian firemen are building up highly-trained drone teams. Eucentre, a research centre at the University of Pavia, can provide useful advice on drones as a resource. 

 

 

Fondazione Eucentre, www.eucentre.it/?lang=en

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