The implementation of automatic diagnostics and monitoring towards diagnosis-aided historic building information modelling and management

The technical and scientific debates agree considering the refurbishment project a challenging process that requires an efficient organization and analysis of the knowledge about the historic artefacts. It is very critical as a result of ambiguities of workflows and information exchanges, dispersion of documentation and the use of inadequate tools to reduce risks caused by these issues. The heritage organisations and professionals are more and more interested in experimenting with innovative methodologies and operative methods to deal with the uncertain context. In the last ten years, discussions and experiments have been undertaken among experts in digital representation of existing buildings about the use of the Building Information Modelling (BIM) approach, whose conceptualization dates back to the seventies. Nevertheless, this approach has implications and developments in the building, infrastructure and manufacturing domains especially in the present and in projection to the future, thanks to the evolution of the digital tools and methodologies of Industry 4.0 that improve the related methodologies. The most recent studies concern with verifying the feasibility of methods and tools for solving the critical issues inherent in the process of managing the building refurbishment project, in order to reduce the risks of errors in the assessment of the conservation status, firstly, and then in the decision about intervention strategies. The proclivity is towards the search for a holistic approach able to manage a variety of resources generating data and information and different analytic methods for knowledge consolidation, in order to understand the specificities and the complexity of the instances of built heritage. This interest has invested the academic and professional environment at international scale and it is in line with the specific needs and problems linked to the refurbishment project at national level. In practice, interest has been transformed into legal obligations as previously occurring in the English context and now in the Italian one. In effect, the CIC (Construction Industry Council) and the British Government led the program to support the formation of the actors within the construction process in the optics of implementing the government's mandate that projects in the public sector would have been managed with the BIM methodology by 2016. In Italy, the Ministerial Decree 560, 1st December 2017, implementing the Procurement Code (Legislative Decree No. 50/2016), defines the methods and timing of the transition to the BIM of the contracting authorities, administrations and economic operators, the obligatory methods and specific electronic tools. This paradigm shift also involves the refurbishment of existing buildings, prompting a more adequate configuration of the BIM approach. In this case, the reverse engineering has no longer the purpose of translating the geometric survey by photogrammetry or laser scans into 2D plants, elevations and sections, rather being a starting point for three-dimensional modelling, aspiring to move from the solid modelling to parametric objects, geometrically and semantically described. Although significant progress was made in research and development of commercial products for automating this process in presence of objects with simple primitive geometries, further investigation is still needed about architectural elements with complex morphology. In this regard, research lines are exploiting the potential of NURBS (Non Uniform Rational Basis-Splines) and meshes in order to accurately represent elements such as vaults and free-form objects, such as sculptural groups. Some studies have underlined, first of all, the need to disseminate a library of parametric objects of architectural components, continuously updated. However, it is only in the last four years that the need to fill a gap in the HBIM approach emerged, because it could be effectively used in the refurbishment process. This gap concerns the integration of methods of performance evaluation, diagnostics an monitoring within a structured system for quality control of the project, in terms of optimization of time, costs and limitation of errors in diagnosis and choice of the intervention line. Therefore, the current research began to investigate the methods for the semantic enrichment of the model during some important phases of the refurbishment process, in order to achieve the appropriate Level of Development in terms of information content, as introduced by the UNI EN 11337: 4-2017 standard in the restoration project. The doctoral studies are being directed towards investigation concerning the representation of knowledge, methods and tools for connecting the different sources of data and information (original paper documentation, geometric survey, diagnostic tests, structural and environmental monitoring sensors, etc.), with a propensity to develop systems devoted to automate diagnosis and support the choice of design, made possible by the versatility of BIM tools based on advanced information technologies (relational databases and cloud platforms, highly customizable). In this perspective, a methodological proposal DA-HBIMM (Diagnosis-aided Historic Building Information Modelling and Management) is introduced, with the aim of automating the diagnosis process by means of algorithms of reasoning, based on a solid Knowledge Base about the phenomena of degradation and failure, and supporting designers in choosing coherent interventions. The damp and crack patterns, so the degradation phenomena, are mapped in 2D and 3D views and the related database shows the semantic attributes about description of damages and building pathologies, images, potential causes, and further data and information. The model is updated through monitoring activities. This specific model, related to the building in a state of decay, can be connected to the 4D-HBIM, the temporal simulation of the transformations and interventions over time, implemented with intervention, in order to support the detection of damages connected with previous human activities. The innovation of the approach is based on the possibility of visualizing, through interrogation tools, the object in the model and its selected properties, to obtain the most efficient sharing of knowledge for all the stakeholders involved (designers, contractors, owners and potential users). In particular, the damp/crack patterns and degradation instances can be isolated and analysed in their informative contents, maintaining their topological relationships within the model. Furthermore, the repository can manage the information obtained from in situ and laboratory tests aimed at the accurate material and technical characterization of the building and its components. The originality of the DA-HBIMM method in supporting the diagnosis may allow the reduction of further damage to the structure and direct the choice of the most coherent solution for functional recovery, structural consolidation and energy retrofit. Hence, the research was planned by objectives: first, the critical review of the state of the art inherent to the existing methods and tools of BIM applied to refurbishment aimed at identifying gaps in knowledge, organizing the state of the art for typology of intervention (energy retrofitting and structural reinforcement); subsequently, the tests of some processes, identified in the literature, were performed and new methods were presented in order to overcome the gaps recognised in the current methodological approaches and to propose a methodological approach. The applications presented in the research area are diversified in order to test the flexibility of the methodology that can be configured according to the specificity of the case in question, since it is a methodology that finds applicability at international level, therefore in building contexts and infrastructures diversified by building culture, social needs and building systems. The next step is the implementation of a HBIM platform, completely dedicated to the refurbishment and management of the building for the real-time inst umental monitoring and the visualization of in-use conditions of the building. In this case, the management of existing buildings during the operation phase is fully possible, before and after refurbishment operations. In this way, reports and suggestions about mitigation activities can be provided when the thermo-hygrometric conditions do not meet the reference thresholds for occupant comfort, energy consumption must be reduced, or health and safety are at risk. The proposed methodological approach is devoted to be developed towards the automation of inferential reasoning by exploiting the potentials of computational systems, methods of image processing and surface analysis in the direction of the implementation of artificial intelligence, promoting the transition from a file-based collaboration to a data-based type, representing a Level 3 BIM maturity and greater interoperability.