A new structural surveillance model for the safety of the building heritage: an innovative methodological approach applied to six school buildings of the Municipality of Salerno

The management of the school building heritage currently represents one of the main challenges for public administrations. A large part of the buildings used for educational purposes was constructed between the 1950s and the 1980s and requires continuous monitoring of its state of conservation, not only in relation to exceptional events, but above all from the perspective of planned and informed maintenance.

Within this context, the project developed by the DICIV of the University of Salerno, in collaboration with the Edil-Test Laboratory, is introduced. The service, scientifically coordinated by Prof. Luigi Petti as Scientific Coordinator and Prof. Rosario Montuori as Scientific Contact Person, was commissioned by the Municipality of Salerno to design and implement a structural surveillance and monitoring system aimed at defining a priority scale for maintenance interventions on six municipal school buildings.

The programme, entrusted through Executive Determination No. 6834 of 22 December 2025, was established with a clear objective: to support the management of the buildings during the period preceding the design and implementation of seismic upgrading interventions, while ensuring the monitoring of the evolution of degradation phenomena and safety conditions.

However, the most innovative aspect of the initiative does not lie in the inspection activity itself, but rather in the methodological approach adopted. The developed model transfers to school buildings the surveillance methodologies already tested in recent years for strategic infrastructures such as bridges, viaducts, and tunnels, integrating them with the specific requirements of the school building heritage. This represents a significant paradigm shift: the objective is not merely to capture the state of conservation of a building at a given moment, but rather to establish a permanent observation system capable of tracking the evolution of degradation phenomena over time and supporting administrative decision-making processes on the basis of objective and continuously updated data.

The monitoring plan, in fact, involves the analysis of the evolution of phenomena such as reinforcement corrosion, concrete cover spalling, concrete deterioration, crack patterns, and deformations affecting floor slabs and roofs, allowing interventions to be scheduled according to priority criteria and economic sustainability.

The project involves six school buildings distributed throughout the municipal area, classified as follows: De Vecchi School (ED01), Medaglie d’Oro School (ED02), Calcedonia School (ED03), Giovi-Piegolelle School (ED04), Giacomo Costa School (ED05), and, subsequently, also the De Filippis building complex (ED06), integrated into the programme as it is structurally connected to the Calcedonia complex. Each building presents different construction characteristics: load-bearing masonry structures, reinforced concrete framed buildings, multiple blocks separated by structural joints, and buildings including gymnasiums and functionally distinct units. This heterogeneity required the definition of an operational model sufficiently flexible to adapt to the different structural configurations while maintaining, at the same time, consistency in inspection procedures and in the assessment of critical issues.

The first phase of the work involved the complete structural decomposition of each building. Each school was divided into independent structural units, subsequently organised according to the different levels and, finally, into the individual construction components. A unique coding system was developed for each element, allowing its position, typology, and function to be unequivocally identified. Floor slabs, beams, columns, walls, staircases, masonry piers, roofs, suspended ceilings, partitions, and infill walls thus form a true digital map of the building, developed through a BIM model that represents the information framework on which all monitoring activities are based. This organisation makes it possible to locate with extreme precision every anomaly detected during inspections and to track its evolution over time, ensuring consistency in assessments even across different inspection campaigns.

For the purposes of the activities envisaged by the Surveillance and Monitoring Plan, the school buildings are subdivided according to their structural, functional, and architectural organisation, as follows:

– ED School Building;

– CP Structural Units;

– LI Levels;

– ES Structural Elements;

– ENS Reference Non-Structural Elements.

Where necessary, school buildings are subdivided into structural units, generally identified by the presence of structural joints and/or different functions and/or non-compact geometric layouts in plan (L-shaped, H-shaped layouts, etc.). Structural units are numbered as follows:

– CS01: Single structural unit;

– CS01, CS02, CS03, …, CS0n: Multiple structural units.

Each structural unit can also be subdivided into levels, starting from the foundation level, as follows:

– LI00: Foundation level;

– LI01: Ground floor;

– LI02, LI03, and so on: First floor, second floor, and so on.

Each structural unit is subdivided into the following types of elements:

– ESPi Columns;

– ESTr Beams;

– ESSe Structural walls;

– ESPa Walls;

– ESSo Floor slabs;

– ESSs Slabs;

– ESSc Staircases;

– ESMM Masonry piers;

– ESFP Spandrel beams.

For each structural unit, considering the actual conditions, some of the following non-structural elements may also be taken into account:

– ENSTO Infill walls;

– ENSTR Partitions;

– ENSCO Roof structures;

– ENSCR Suspended ceilings;

– ENSAL Other elements.

Ultimately, each element composing a generic school building is uniquely identified as follows:

ED01.CS01.LI00.ESPi

The operational model is based on a system of periodic inspections structured into ordinary and extraordinary surveys. The former are carried out according to a predefined schedule and aim to verify the state of conservation of the structures through standardised inspection forms; the latter are activated in the presence of specific events or whenever situations arise that require further investigations.

For each inspected element, detailed information is collected regarding its state of conservation, accompanied by photographic documentation, a description of the anomalies, and an assessment of the detected defects. The entire process is supported by classification criteria that allow interventions to be prioritised on the basis of the severity of the observed critical issues and their potential evolution over time.

The monitoring report produced at the end of each inspection cycle therefore does not constitute a simple descriptive document, but rather a technical tool through which future maintenance activities can be planned in a rational and systematic manner.

 

Alongside visual inspections, the plan also includes instrumental monitoring activities dedicated to the main crack patterns present in the buildings. Where necessary, electronic monitoring systems with periodic reports have been envisaged and/or implemented to control the evolution of the existing conditions, including, for example, the development of crack patterns.

The integration between direct observation, also carried out through infrared surveys, and continuous data acquisition makes it possible to distinguish between stabilised phenomena and processes that are still evolving, improving the ability to interpret the structural behaviour and reducing the risk of either unnecessary interventions or, conversely, the underestimation of potentially critical situations.

The first monitoring cycle represented the phase in which the so-called “baseline” was established, namely the initial knowledge framework against which all future inspections will be compared. The activities systematically involved every structural component identified in the six buildings, making it possible to document the initial conservation conditions and classify the observed degradation phenomena according to homogeneous criteria.

This initial assessment is of fundamental importance because it allows subsequent monitoring campaigns to evaluate not merely the presence of a defect, but rather its evolution over time. It is precisely this ability to compare homogeneous data collected at different moments that transforms monitoring from a simple inspection activity into a genuine tool for structural risk management.

From a management perspective, the model also makes it possible to overcome a traditionally reactive approach to maintenance, based on intervention following the occurrence of emergency situations. The periodic acquisition of information allows the early identification of the onset of degradation phenomena, the monitoring of their progression, and the planning of interventions before critical conditions reach levels capable of compromising the functionality and safety of the structures. In this way, maintenance takes on a predictive character, enabling a more effective allocation of economic resources and improved planning of interventions by the municipal administration.

The experience gained from the Salerno case study highlights how the methodologies developed in recent years for the management of major infrastructures can be effectively adapted to public buildings as well, contributing to the definition of new standards for the management of existing building assets. The availability of digital models, standardised inspection procedures, objective criteria for defect classification, and continuous monitoring systems makes it possible to transform structural assessment from an occasional activity into a permanent knowledge-based process.

From a broader perspective, an approach of this type could be extended not only to school buildings, but also to hospitals, strategic buildings, and public properties, contributing to the dissemination of a culture of preventive maintenance based on systematic observation, data analysis, and intervention planning.

This is, most likely, the main innovation introduced by the project: not merely a set of inspections, but a methodological model designed to support a more efficient, informed, and sustainable management of the structural safety of public assets.