The technical causes of the collapse of Annone overpass on SS.36 (original) (raw)
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In the last four years, Italy experienced the collapse of five road bridge: Petrulla viaduct (2014), Annone (2016) and Ancona (2017) overpasses, Fossano viaduct (2017) and Polcevera (2018) bridge. Although for deeply different reasons, the collapses occurred can all been gathered into the same common cause: the (lack of) knowledge of the effective structural condition, a serious problem that affects existing constructions. As it will be shown in the paper, different problems such as missing of the as-built designs, an appropriate construction and movement precautions, a heavy vehicle checking, and a material decay monitoring can nevertheless be addressed as an inadequate knowledge of what is happening to/in the structure. In the first section, the paper will report a short description of the failures for the five bridges, while in the second part a main set of problems involved in bridge safety and maintenance will be discussed. Finally, in the third part, a review on innovative and peculiar investigation and monitoring techniques will be illustrated. The collected results can shed new light on future perspectives for the Civil Engineering sector, sector that has to be ready for facing the challenges of preservation, restoration and/or replacement of the existing infrastructural constructions, worldwide.
Relevant outcomes from the history of Polcevera Viaduct in Genova, from design to nowadays failure
Journal of Civil Structural Health Monitoring, 2020
Failures of structures are often tragic events, however represent an opportunity to improve the understanding of phenomena. In this paper, after the review of Bridge collapses, on August 14, 2018, the history of Polcevera Bridge is presented, starting from aging considerations done by its designer Riccardo Morandi in 1981, analyzing the outcomes of inspections in the years from mid '80s with references to Italian Regulations on inspections, the interventions done during bridge life, and finally some considerations on its collapse. The case is certainly a reference for reinforced concrete bridges built just after the 2nd world war in a highly corrosion-prone environment due to nearby sea and industrial as well as chloride pollution. Large reference is done to data included into the Report of the Commission of Italian Ministry of Infrastructures for the failure of Polcevera Bridge. Monitoring for assessment of performance decay due to corrosion is discussed with reference to the meaningful example considered.
Lecture Notes in Civil Engineering
Bridges are crucial elements in the transportation networks. The failure of one of these structures causes generally important economic and social consequences on the whole road network. However, the current state of preservation of bridges and the recent collapses happened in the Italian territory shows that the level of attention of the stakeholders and managers on these structures was not sufficiently high. However, the numerosity of the existing bridges, the variety in terms of geometrical and material characteristics together with the limited technical and financial resources make impossible to analyze in a suitable amount of time all the bridges present in the Italian territory. With the aim of overcoming such difficulties, the Italian Ministry of Infrastructures and Transport (MIT) published unified guidelines for the classification and the risk management, safety evaluation and monitoring of existing bridges. The guidelines propose a multi-level approach, organized in different levels of analysis. To each level corresponds an increasing level of commitment, in both economic and technical terms, for the knowledge of the structures and of the aspects influencing the possible sources of risk. The paper illustrates the multilevel approach for the classification of the existing bridges proposed by the ministerial guidelines and presents and discuss all the background information and methods adopted to develop this multilevel classification.
Infrastructures
Bridges are essential for guaranteeing the functioning of transportation systems since their failure can cause serious threats to the safety, well-being and economy of modern communities, especially in emergency conditions. Following recent bridge failures, among which include the Morandi bridge in 2018, specific guidelines on risk classification and management, safety assessment and monitoring of existing bridges have been issued in Italy by the Minister of Infrastructure as a mandatory code. They pay particular attention to the evaluation of the residual life span of critical transportation infrastructure dating back to the 1950s and 1960s of the last century. Being a newly issued tool, the Guidelines need to be applied and tested in order to find possible drawbacks and to point out the main factors influencing their results. Therefore, in this study, after a short description of the Italian Guidelines, pointing out some differences with other approaches adopted worldwide, some ad...
Dynamics and causes of the collapse of the Morandi viaduct in Genoa
2019
The mistaken conjectures formulated for the collapse of the Morandi viaduct in Genoa may have been formulated in the sudden search for a scapegoat or, perhaps more painfully, for economic and political reasons: but the data collected, the studies carried out, the elements reported in my analysis do not prove the structural collapse as the cause of the fall of the viaduct on Polcevera. The collapse was tragic and perhaps could have been avoided: the road managers, with a high-level weather warning system and an electric storm warning in extraordinary circumstances, should have put in place all the security procedures. The study presented here, with precise photographs and analyzes, explains how the impacts of climate change with the inability to predict risk have led to the collapse of the viaduct Figure 1 The collapse of the Morandi viaduct in Genoa on the photo taken by the Guardia di Finanza helicopter 1. Description of the bridge status Polcevera viaduct has been continuously inv...
Infrastructures
The Italian infrastructure network of roads and bridges is one of the most complex in the world due to the territory orography. Italy is strongly interested in seismic and hydrogeological hazards, and, in addition, degradation and obsolescence phenomena are common in infrastructures nowadays approaching the end of their nominal life. Furthermore, these infrastructures are subjected to continuous traffic load increase over time. In 2020, the Italian Ministry of Infrastructure and Transport (MIT) published the guidelines for risk classification and management, safety assessment, and monitoring of existing bridges (LG2020) as an attempt to unify the multiple procedures of inspection, monitoring, and maintenance of infrastructures. The multilevel approach proposed in the Italian guidelines for the management of the complex existing system of bridges is herein discussed and investigated, focusing on an operational methodology to evaluate the impact of structural defects on the risk asses...
Discussion. Structural Accidents and Their Causes
Proceedings of the Institution of Civil Engineers, 1978
Since the completion of the Paper we have investigated the backgrounds of structural failures in two quite diverse industries. One concerned the collapse of the 22 storey block of flats called Ronan Point, in May 1968. The other case history featured the break-up in mid-air of the airship R38 in August 1921. 51. It was found that broad similarities in the pattern of development of geometric scale, in the absence of experimental research, were present in both the incidents and, indeed, linked them to the four bridge histories outlined in the Paper. Thus, the conclusions we present are quite general to structural engineering and not confined to bridge construction. We would like to emphasize that only one category of structural failure has been discussed in the Paper, but also it is felt that much could be done to avoid similar incidents in the future.
Seismic Vulnerability of the Italian Roadway Bridge Stock
Earthquake Spectra, 2014
This study focuses on the evaluation of the seismic vulnerability of the Italian roadway bridge stock, within the framework of a Civil Protection sponsored project. A comprehensive database of existing bridges (17,000 bridges with different level of knowledge) was implemented. At the core of the study stands a procedure for automatically carrying out state-of-the-art analytical evaluation of fragility curves for two performance levels—damage and collapse—on an individual bridge basis. A WebGIS was developed to handle data and results. The main outputs are maps of bridge seismic risk (from the fragilities and the hazard maps) at the national level and real-time scenario damage-probability maps (from the fragilities and the scenario shake maps). In the latter case, the WebGIS also performs network analysis to identify routes to be followed by rescue teams. Consistency of the fragility derivation over the entire bridge stock is regarded as a major advantage of the adopted approach.
Once upon a Time in Italy: The Tale of the Morandi Bridge
Structural Engineering International, 2018
On 14 August 2018 at 11:35 AM, a relevant portion (about 243 m) of the viaduct over the Polcevera river in Genoa collapsed, killing 43 people. The bridge was designed in the early 1960s by Riccardo Morandi, a well-known Italian engineer, and opened to the public in 1967. The collapsed part of the bridge essentially comprised an individual self-standing structure spanning 171 m and two simply-supported connecting Gerber beam systems, each spanning 36 m from the self-standing structure to the adjacent portions of the bridge. This paper aims to reminisce the complete story of the bridge, from the Italian construction boom in the 1960s to some of the issues that soon arose thereafter: the strengthening intervention in the 1990s, the subsequent structural monitoring and, finally, the strengthening project never brought to fruition. Potential reasons for the collapse are discussed, together with some of the possible inadequacies of the bridge, its maintenance and loading history based on critical reflection, comparison with specific features of bridge construction practice today and results obtained using numerical models with different levels of refinement. Since the entire matter (specifically the debris) was considered classified by the investigating magistrate in the immediate aftermath of the bridge collapse, this work is based entirely on publicly available material.
History of a Faulty Retrofitting: The S. Sebastian Bridge in Loano (Italy)
2016
Masonry bridges are well inside the European monumental heritage; even though protected by the Preservation Authorities, their retrofitting does not always follow rational approaches. In this paper, the case study of the S. Sebastian Bridge in Loano (Italy), a pedestrian bridge dating back to 1691, is discussed. The collapse of the aedicule, and the subsequent collapse of the armilla, are found to be the result of several causes: i) poor and non-rational original design; ii) degradation of poor materials due to environmental actions; iii) wind-induced fatigue collapse of some material; iv) thermal stresses due to the dilatation of a modern concrete pavement. The retrofitting criteria proposed for this case are discussed comparing their effectiveness and the conservation of the monumental value of the bridge