The Morandi Bridge (Polcevera Viaduct) in Genova

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The Morandi Bridge (Polcevera Viaduct) in Genova

The highway bridge spanning over the river Polcevera, linking Milano and Genova with the Riviera dei Fiori and France, was designed by Riccoardo Morandi and opened to traffic in 1967. The bridge is approximately 1200 meters long, divided into 11 spans of different length; the longest being 207 m. On 14 August 2018, a 210-metre section of the viaduct collapsed during a rainstorm on 14 August 2018. 43 people died

Purpose and content

The aim of the studies presented on this site is to explain construction principles, to document the pre-collapse appearance of the bridge, and to understand collapse dynamics as more public evidence appears.

Guiding question

Which structural element(s) first failed, and triggered the subsequent collapse?

Motivation

The very special static construction of this viaduct triggered my curiosity since my childhood. I finally started documenting Morandi bridge first in 2007 [here], and later more exhaustively in 2015 during my visit on-site [here].

The failure of the bridge on 14 August 2018 motivated me to first learn about the Morandi's concepts and construction principles [here], and subsequently investigate about the collapse.

Limitations

This study is mostly based on curiosity, hopeful good-sense and educated guessing. I do not claim scientific soundness.

Method

The study is an ongoing attempt, strongly relaying on a number of frame-by-frame analysis and aggregation of CCTV footage that “appeared” over time in public one-by-one.

A first private smartphone video was published right after the event, showing the collapse from the distance, nourishing a wide variety of hypothesis about collapse dynamics and causes.
August 20, 2018: Authorities subsequently released further CCTV footage, but none of the two new video clips showed significant parts of bridge decks or pylons. Thanks to a thorough frame-by-frame anaylsis [here] of the bridge shade on the wet ground surface, collapse dynamics became a little bit more clear, this enabling some very first educated guess about the structural parts that initially failed.
August 24, 2018: By aggregating the two most recent videos with the previous one, I could show first evidences about collapse dynamics [here]. At that time, it was not (publicly) known yet, which of the four prestressed beams of pylon 11 first failed. In fact, trying to assess post-incident images of bridge debris did not allow for a coherent understanding of collapse dynamics. Questions like which parts failed first or in which sequence the complex structure came down, remained controversially unanswered.
July 9, 2019: Only more than 10 months after the incident, Italian Authorities released another seized CCTV video. Finally, this footage framed entire pylon 11 and bridge decks coming down. Due to the nature of the CCTV system in place, many frames were missing or duplcates, resulting in a stuttering video hard to follow. Therefore, I reworked the footage into smaller clips. This finally opened the way to answer the main question by localizing the root spot [here] that initiated the collapse, high up on the southeast beam on pylon 11.

Morandi Bridge: anaylsis of the Ferrometal CCTV video clip in six enhanced sequences

On July 1st, 2019, Italian authorities finally a long announced and valuable CCTV footage, showing the bridge structure while it collapsed. The following study is based on evidences taken from this video. The study suggests that the root cause of the failure sequence is given by the rupture of the south-eastern concrete cable stay in proximity of the top of the A-pylon.

>> Read: Morandi Bridge: anaylsis of the Ferrometal CCTV video clip in six enhanced sequences <<

Analysis: July 8th, 2019 *Update*
Analysis: July 4th, 2019 *Initial Version*

(IT) La dinamica del crollo - Videocamere aggregate (video) .

Grazie alla sincronizzazione di tre videocamere che hanno ripreso il crollo, diventa parzialmente possibile di sintetizzare la dinamica del crollo. Il video basso di origine è stato stabilizzatè con buona cura i parametri dell'immagine ottimizzati frame per frame per massimizzare dettagli utili.

>>La dinamica del crollo - Videocamere aggregate"<<

Analisi video: Agosto 30, 2018 *Aggiunto simulazione collasso*
Analisi video: Agosto 24, 2018 *Versione iniziale*

Analysis of collapse dynamics: The Mirror Cinema

On August 20, 2018, authorities released a first security camera video of the bridge collapsing. Unfortunately, the field of view includes only the road level of pillar. While it gets submerged in dust and falling debris. However, a blurry image of the bridge deck reflecting on the wet roof of a building reveals more, especially relating to the important first instants of the collapse.

>>Read "Video analysis of collapse dynamics: The Mirror Cinema"<<

Analysis: August 21, 2018 *Update*
Added Section 6: a simplified 3D perspective field of view analysis.
Analysis: August 20, 2018
Initial version.

Understanding Morandi's design choices

Article: December 15, 2021 update

After bridge collapse a few days ago, many Experts appear to know about design flaws or lack of maintenance of this bridge. For my part, I am first interested to understand the design choices that determine the very special configuration of this bridge.

Why has Riccardo Morandi opted for this kind of structure? What are the ideas behind it?
So I went through a number of articles with scientific or engineering approaches dealing with Morandi-type bridges, and wrote down a first modest explanation about the (in-)famous post-stressed concrete stays that characterize the bridge statical layout.

>> Read the first part of "Understanding Morandi" (*updated* December 21)

Comment on this page...

14: Guest - 6.6 years ago	Aug 22, 2018, 2:41:35 PM
The final report of the restoration done the the stays of pine number 11 in 1993 can be found on Facebook. Search: AICAP '93- Risanamento Stralli Polcevera- Ing.pisani

13: Guest - 6.6 years ago	Aug 21, 2018, 9:47:31 PM
and here a link to the paper from Morandi about long term behavior and corrosion, 1979: https://webapi.ingenio-web.it/immagini/file/byname?name=riccardo-morandi-durabilita-ponte-pp.pdf

12: Guest - 6.6 years ago

Aug 17, 2018, 8:43:28 AM

Non avevo letto quanto scritto dall'amministratore qui sotto.
Mi scuso.

Note by the Admin:
I am sorry, the article you correctly state is not available on this site, it
was public by mistake, but was intended as an internal resource only. After the
bridge collapse I stepped through the public documentation on this page and
discovered and corrected my mistake. I preemptively apologize to Prof. Giovanna
Franca for having published her work on my site without her consent. No further
conspiracy theories apply (referring to a comment below)

11: Guest - 6.6 years ago	Aug 17, 2018, 8:24:04 AM
Una copia del documento è presente anche su "Wayback machine"

10: Guest - 6.6 years ago	Aug 17, 2018, 8:22:31 AM
Avevo pubblicato un post in cui indicavo che il documento "scomparso" era ancora presente nella cache di Google: perchè è stato rimosso il mio post ?

9: Guest - 6.6 years ago	Aug 15, 2018, 1:04:12 AM
thanks Rino very interesting reading!

8: Guest - 6.6 years ago

Aug 14, 2018, 11:27:02 PM

The article "Il consolidamento del Viadotto sul Polcevera" from Prof.ssa
Giovanna Franco is still available via the "Weblink" at the end of the german
page of Wikipedia about the Polcevera viaduct.
Rino

7: Guest - 6.6 years ago	Aug 14, 2018, 11:03:57 PM
Credo fosse tratto da "Il consolidamento del Viadotto sul Polcevera" di Giovanna Franco. Giovanna G.

6: Guest - 6.6 years ago	Aug 14, 2018, 10:47:00 PM
thanks for explanation, Angelo

5: Guest - 6.6 years ago	Aug 14, 2018, 10:46:45 PM
Anch'io vorrei rileggerlo, grazie.

4: Guest - 6.6 years ago

Aug 14, 2018, 6:30:27 PM

the author of the article was prof. Giovanna Franca (Genova University). Title:
“il consolidamento del 
viadotto sul Polcevera” 
Unfortunately is not available anymore

Note by the Admin:
I am sorry, the article you correctly state is not available on this site, it
was public by mistake, but was intended as an internal resource only. After the
bridge collapse I stepped through the public documentation on this page and
discovered and corrected my mistake. I preemptively apologize to Prof. Giovanna
Franca for having published her work on my site without her consent. No further
conspiracy theories apply (referring to a comment below)

3: Guest - 6.6 years ago

Aug 14, 2018, 5:59:58 PM

Mi associo alla richiedta, l’articolo è stato cancellato poco dopo le 15:00
era molto interessante e dettagliato sulle opere di ristrutturazione con una interessante descrizione 
tecnica degli ammaloramenti della struttura, penso l’articolo fosse del 2015, purtroppo non ricordo la 
firma dell’autrice. C’è da chiedersi perché sia stato cancellato. Sarebbe interessante poterlo 
rileggere alla luce di quanto successo. Grazie.   Franco

2: Guest - 6.6 years ago	Aug 14, 2018, 5:03:01 PM
buonasera. mi associo alla richiesta del signor Angelo. Lo avevo letto e lo avevo trovato molto interessante. cordialmente, Francesca

1: Guest - 6.6 years ago

Aug 14, 2018, 4:22:09 PM

the long technical article about the Morandi Bridge in Italian was cancelled from this site just after the 
collapse, it was an interesting article, it’d be of interest to have it back here, 
hope to read it again,  thanks, Angelo