We are pleased to announce our involvement in another exciting project, this time in Italy, where we are contributing our software to analyze data from the Serra Cazzola bridge spanning the valley of the same name. The project is managed by Italian ANAS and involves ESSEBI Srl. and Dewesoft.

The Serra Cazzola viaduct, in the province of Agrigento, represents one of the main works of the State Road 640 of Porto Empedocle, which connects Agrigento to Caltanissetta, passing through the famous archaeological site "The Valley of the Temples" recently recognized by UNESCO as an asset of global interest. The bridge is nearly 1000 meters long, with the maximum height reaching 70 meters above the valley floor at the central part. The bridge has 12 spans with lengths of 55 m, 70 m, three spans of 90 m, 120 m, three spans of 90 m, two spans of 70 m, and 55 m, totaling 980 meters in length.

This project is groundbreaking in many ways, and with recent bridge collapses, the motivation behind it is clear.It is well-known that much of Italy’s infrastructure dates back to World War II, making it essential to test new and innovative methods for monitoring and maintenance. This project aims to do exactly that.

For the measuring part, a total of 85 accelerometer modules have been installed on the bridge for the project, all provided by Dewesoft. This includes exactly 71 IOLITE 3xMEMS modules, 10 IOLITE 3xMEMS of the waterproof type, and four E-g-meters.

The measurements from these modules are sent directly to ESSEBI Srl, where they are analyzed in real-time. It is in this part of the process that we have been given the opportunity to assist by analyzing data from the bridge using ARTeMIS Modal Pro, which is specifically designed for this type of output-only analysis

The measurements were analyzed by ARTeMIS Modal Pro version 8.0. The project consists of 249 channels simultaneously recorded. To reduce data redundancy six projection channels were used which significantly increased the performance of the estimation techniques. The measurement were decimated down to a Nyquist frequency of 2.5 Hz. A high-pass filtering was made to get rid of large DC components in the data.

Both the Enhanced Frequency Domain Decomposition (EFDD) estimator and the Extended Unweighted Principal Component Stochastic Subspace Identification (SSI-UPCX) estimator were used. EFDD provided a quick overview of most of the modes and works well in this case due to the lightly damped modes of the bridge. SSI-UPCX automatically found 26 modes ranging from 0.6 Hz to 2.3 Hz.

Additional modes were estimated by SSI-UPCX but were subsequently deleted due to their high correlation with other modes. The level of correlation was determined using the Modal Assurance Criterion (MAC). When deciding which of the two highly correlated modes to delete, the one with the highest mode shape complexity was chosen for removal. This post analysis was made in the Validation Task in ARTeMIS Modal Pro.

SSI-UPCX Operational Modal Analysis of the Serra Cazzola Bridge.

Validation of modal results using the Validation Task in ARTeMIS Modal Pro.

ESSEBI Srl will be using ARTeMIS Modal Pro with its SHM plugins to study the long-term development of the dynamic behavior of the bridge until complete management is fully handled by ANAS with its interoperability network.

More information will be provided later. Don't forget to subscribe to our newsletter and stay tuned for exciting updates on this and other projects!

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