Suspended pedestrian connection between the public prosecutor’s offices and the court house in Naples
The activity involved providing scientific consulting services to support the design of a suspended pedestrian walkway connecting the buildings of the Public Prosecutor’s Office and the Palace of Justice in Naples, for which AICI ENGINEERING S.R.L. was the structural designer [1].
In particular, the structural body of the walkway consists of metal trusses, with upper and lower chords in HEB profiles, uprights and crossbars in HEA solid wall profiles, crossbars in IPE profiles supporting the corrugated sheet metal forming the walking surface, and a roof in corrugated sheet metal panels with an interposed layer of polyurethane insulation. The substructure consists of two piers spaced approximately 25 m apart, made of reinforced concrete, and foundations consisting of plinths on piles. Each pier consists of two columns of the same height, connected by a pulvinus, also made of reinforced concrete. A structural discontinuity is planned between the superstructure and the substructure through the creation of an insulation interface.
3D Model View – Architectural and Structural
This interface is created using isolators, i.e., special support devices characterized by low stiffness with respect to horizontal movements and high stiffness with respect to vertical movements. The seismic protection strategy adopted allows the motion of the superstructure to be decoupled from that of the substructure so that the deformations of the superstructure are concentrated essentially at the isolation plane. In this way, during a seismic event, the superstructure behaves like a rigid body oscillating on the isolation level [2].
The isolation system involves the use of FIP-SI type elastomeric isolation devices. The elastomeric isolators of the SI series are reinforced rubber supports consisting of alternating layers of steel laminates and hot-vulcanized rubber. These devices are characterized by low horizontal stiffness, high vertical stiffness, and adequate damping capacity.
These characteristics make it possible to increase the fundamental vibration period of the structure, to resist vertical loads without appreciable settling, and to limit horizontal displacement in seismically isolated structures.
Detail of type of insulator used
Given the potential significance of the structure and the volcanic/seismic/geotechnical conditions of the site, the project involves the installation of a monitoring system consisting of accelerometers and inclinometers, as well as a thermal probe. This will make it possible to characterize the dynamic response of the structure under operating conditions, monitor its response under seismic conditions, monitor any inclinations of the piers, and check for thermal variations in order to assess their relevance to the structural response.
Summary diagram of the monitoring network
The planned monitoring network uses the Dewesoft platform [3] for dynamic data management, as it represents an integrated solution for the acquisition, analysis, and real-time control of structural and environmental data. It is complemented by the Leica Geosystems platform [4], which is dedicated to the acquisition, analysis, and management of static data.
Robust technologies based on very low noise dynamic sensors (accelerometers), normally used in complex industrial contexts, have been adopted. These devices guarantee high reliability, as well as the possibility of expansion and rapid reconfiguration in the event of changes in real conditions.
Schematic layout of the Dewesoft acquisition chain
The Dewesoft acquisition chain guarantees microsecond data synchronization, ensuring high accuracy of signals generated by all channels. Each unit is also certified to operate in environments with high electromagnetic interference and in contexts where high robustness and reliability are required, making it ideal for critical applications such as the railway, industrial, and aerospace sectors, where signal reliability is essential.
View acquisitions using the Dewesoft platform
In addition, the static devices integrate laser distance meter and triaxial clinometer functions, allowing the monitoring of any relative movements or deformations between the pairs of piles and the underlying foundation plinths on piles. Furthermore, a thermal probe will be installed in order to monitor environmental conditions.
The monitoring system will essentially consist of the following types of sensors and devices:
– WiSenMeshWAN Omni Tilt&Distance Node: these are nodes with integrated sensors, specifically with triaxial inclinometer and distance meter functions (they can measure the distance from any surface up to 100 m without the use of reflectors). The node includes a temperature sensor, wireless transmitter via external antenna, and power autonomy of up to 5 years;
Omni Tilt&Distance Node
– IOLITEiw-3xMEMS-ACC-8g-T: Accelerometro MEMS triassiale impermeabile con interfaccia EtherCAT integrabile con un sensore di temperatura esterno ed integrato di dispositivo di conversione Analogico-Digitale.
IOLITEiw-3xMEMS-ACC-8g-T
BIBLIOGRAPHY
[1] AICI ENGINEERING s.r.l. was founded in September 2005, combining the experience gained in over fifteen years by the professional association A.I.C.I., which, due to changing market needs and the expansion of its activities, has brought in new professionals who are experts in various fields of architecture, engineering, and services in general. https://www.aiciengineering.it/. Under the guidance of architect Valentino Tropeano, who has always been a strong believer in teamwork, the company brings together the skills of professionals with extensive experience in architectural, structural, plant engineering, and environmental design, construction management, and accounting in the public and private construction sectors, restoration and conservation, urban redevelopment and regeneration, and seismic vulnerability assessments of strategic buildings. The group, which is actively involved throughout Italy, has twenty years of experience in reconstruction work in the Campania and Basilicata regions, as well as in assessing the seismic safety of public buildings used by law enforcement agencies, offices, and schools.
[2] B. PALAZZO – L. PETTI “Aspects of structural vibration passive control.” International Journal of MECCANICA Vol. 32 No. 6 Dec. 1997.
[3] Dewesoft is a company that supplies measurement and testing instruments. Its headquarters are located in Slovenia, https://dewesoft.com/it. Design, manufacturing, and testing are carried out directly at the headquarters; system calibration is performed by internal laboratories certified according to ISO 9001 and ISO 17025 standards. The main fields of application are industrial, automotive, aerospace, acoustic, civil, and electrical. The plug-and-play instrumentation offers the possibility of creating complex analysis systems that are easy to configure, with high accuracy and precision, and the acquisition software can be used for real-time or post-acquisition data analysis.
[4] Leica Geosystems has been revolutionizing the world of surveying for over 200 years with comprehensive solutions for professionals around the globe, https://leica-geosystems.com/it-it/. The company is known for its premium products and for developing innovative solutions for collecting, analyzing, and presenting spatial information. That is why professionals in many industries, such as surveying and GIS, construction and machine control, manufacturing, aerospace, and public safety, rely on Leica Geosystems. Leica Geosystems stands for precise instruments, modern software, first-class service and support, and comprehensive services. Leica Geosystems is a leading provider of measurement solutions. Through its internal ISO9001:2008 quality standards, the company ensures that every product, wherever it is manufactured, meets the highest quality requirements.
Please visit the link below for further informations on monitoring system: https://biblus.acca.it/modello-operativo-pozzuoli-monitoraggio-dinamico-mediante-accelerometri-di-fabbricati-campione-a-pozzuoli-na/