I-BIM: revolutionizing infrastructures with information modeling

The I-BIM (Infrastructure Building Information Modeling) is the application of the BIM methodology to the infrastructure sector and allows for the digital modeling and management of works such as roads, railways, bridges, tunnels, and technological networks throughout their entire life cycle, from design to maintenance. Unlike traditional BIM, which is building-oriented, I-BIM is specific to linear and horizontal infrastructural works, characterized by high complexity and strong interaction with the territory.

Digitalization is profoundly transforming the way infrastructures are designed, built, and managed. The need to coordinate geometric, technical, and managerial information requires tools capable of ensuring consistency, quality, and continuity of data over time. In this context, Infrastructure-Building Information Modeling fits in, integrating 3D geometric representation with functional and performance data, supporting all phases of the project life cycle.

Through geospatial digital twins, infrastructural models can be managed within their geographical context, improving analysis, control, and management of assets in a smart infrastructure perspective. In the following paragraphs, we will delve into how I-BIM allows for the optimization of processes, coordination, and management of infrastructural works.

The role of BIM in infrastructural projects and how I-BIM expands its capabilities

The Building Information Modeling has progressively extended its scope of application to infrastructural projects as well. However, roads, railways, bridges, and technological networks present characteristics that are profoundly different from buildings, related to the linear development of works, the close relationship with the territory, and the high geometric and functional complexity.

To meet these needs, Infrastructure-Building Information Modeling (I-BIM) was born, an evolution of BIM dedicated to the design, construction, and management of infrastructures. I-BIM introduces specific modeling and data organization methods for extensive and complex works, such as transport networks and territorial-scale infrastructural systems.

Through I-BIM, it is possible to create infrastructural information models that integrate:

• the geometric representation of linear works;
• the technical and functional information of infrastructural elements;
• the data supporting management, maintenance, and monitoring activities of assets over time.

The I-BIM model thus serves as a central tool for the entire life cycle of infrastructures, as it promotes interoperability among the various stakeholders involved and supports Infrastructure Project Management processes in the different phases of the project.

The main advantages of BIM for infrastructures throughout the entire project life cycle

The adoption of BIM in the infrastructural field allows for concrete benefits in all phases of the project life cycle, from planning to long-term management. The I-BIM approach allows for the structuring and continuous use of information in a coherent manner, avoiding data fragmentation between the different phases of the project.

The main advantages of I-BIM for infrastructures include:

• higher quality of design, thanks to multidisciplinary coordination and early verification of technical solutions;
• reduction of errors and interferences, with a positive impact on time, costs, and changes during construction;
• more effective control of the construction phase, through reliable and constantly updated informational models;
• support for management and maintenance activities, through “as built” models that can be integrated with Asset & Facility Management systems;
• enhancement of the infrastructural heritage, through structured data usable for analysis, monitoring, and planning of future interventions.

Advantages of I-BIM

The most common challenges in adopting BIM for infrastructure and how I-BIM addresses them

The application of BIM to infrastructure projects involves certain critical issues, related to the very nature of the works and the complexity of the processes involved. Compared to construction, infrastructure requires the management of extensive models, strongly related to the territory and characterized by a multitude of disciplines and actors.

Among the main challenges, we can identify:

• interoperability between software and different disciplinary models;
• standardization of information, necessary to ensure consistency and reliability of data;
• management of complex linear infrastructures, often developed over large territorial extents;
• integration with territorial data and external systems, such as GIS and asset management platforms.

I-BIM addresses these issues through the adoption of openBIM standards and structured information models, capable of supporting the exchange and reuse of data throughout the entire lifecycle of the work. A fundamental step in this direction has been the overcoming of the IFC 2×3 standard, conceived mainly for construction, in favor of the new IFC 4.3 standard, developed for a more effective representation of infrastructures.

The IFC 4.3 standard introduces a more flexible data structure that aligns with the needs of linear works, improving coordination between disciplines, the quality of information, and the efficiency of workflows. To support this transition, there are software tools to transform an IFC 2×3 model into an IFC 4.3 file, as well as dedicated solutions for complete IFC file editing.

IFC 4.3: A New Standard for Infrastructures

In the realm of I-BIM, the IFC 4.3 format is a significant milestone. This new version introduces a wide range of definitions to represent infrastructural construction projects in a structured and understandable manner.

Critical in this context is the use of Work Breakdown Structure (WBS), which not only enhances the design value but also facilitates understanding and interaction with the project by all stakeholders. Establishing common standards through IFC 4.3 helps simplify processes across the entire project lifecycle, enhancing system adaptability, defining design requirements, validating digital models for various purposes.

The new features of the IFC 4.3 standard include:

• Spatial Structure – Maximum flexibility in creating complex spatial structures as per model use. This differs from the previous version where the spatial structure related to buildings was relatively fixed.
• Alignment (Semantic + Geometric) – Fundamental for defining linear infrastructure, Alignment allows defining the path by breaking it down into its Semantic and Geometric parts, particularly defining horizontal, vertical curve profiles, and cant (elevation).
• Parametric Extrusions along Alignment – Ability to define solids based on predefined profiles (e.g., rails, ballast, sub-ballast, etc.) to and from precise points along the path.
• Linear Object Placement – Ability to define object position not only through its X, Y, Z coordinates in space but also its position along the Alignment, with potential lateral, vertical, and/or longitudinal offsets. This also implements the concept of “stationing,” indicating an object’s kilometric position (e.g., this signal is at km 3+200 along a specific path).

These new concepts, crucial for linear infrastructures, integrate with existing concepts like:

• Assemblies and Decompositions – Useful for deciding the object decomposition level; for instance, a traffic light could be broken down into the pole and the actual light.
• Properties and Groups – Properties define the necessary information level, while groups help create cross-sectional groupings added to spatial decomposition.
• Doors and Connections – Mainly for wiring, sewers, etc., adding further semantic information to the model.

Combining all these elements, along with new IFC classes defined for objects in each infrastructure domain (e.g., sleepers or rails in a railway context rather than signals in a road context), enables creating an IFC model rich in all the necessary information for asset linear digitalization.

The IFC 4.3 standard is currently in the final “FDIS” approval phase to attain international accreditation as an ISO standard. The FDIS voting process is expected to conclude this year, allowing publication by early 2024.

Classification and Definition of Objects in IFC 4.3

Specifically, IFC 4.3 categorizes elements of an infrastructure project into three primary thematic groups:

• Objects (ifcObjectDefinition): Encompass tangible physical objects like structural components, stakeholders, processes, and costs.
• Properties (ifcPropertyDefinition): Information and characteristics that can be associated with objects.
• Relationships (ifcRelationship): Interdependencies and connections between various objects.

IFC Data Schema Composition Diagram

An actual example is ifcProduct, an abstract entity representing any object in a geometric or spatial context, such as physical products, spatial elements, and even non-physical elements like annotations and alignments.

Here’s a video on creating the informational structure of an IFC 4.3 file:

Example of Road Models and their Representation in IFC 4.3

Focusing, for instance, on road models, IFC 4.3 allows describing these complex projects through entities like ifcSpatialElement, ifcElement, ifcLinearElement, and ifcPositioningElement. For example, ifcSpatialElement represents the spatial division of a road project, including elements like roads, bridges, tunnels, allowing project division into different areas or sites.

This division aids coordination among various project stakeholders, from design to construction. Each area encompasses the design and construction of different objects, ranging from tunnels to bridges, railways, roads, buildings, to technical devices.

Physical Components and Annotations in IFC 4.3

Concerning physical components, ifcElement includes elements constituting the physical structure of a road, like pavements, curbs, open ditches, etc. Additionally, IFC 4.3 enriches the representation of these structures, offering the ability to further detail object division through subcategories like ifcBridgePart or ifcRoadPart.

Annotations (ifcAnnotation) play a crucial role in providing supplementary information, like pavement layer edges or other components vital for surveyors and other project-involved professionals.

How IFC 4.3 transforms BIM workflows for roads, railways, bridges, and tunnels

The introduction of the IFC 4.3 standard has a direct impact on BIM workflows applied to infrastructure, as it allows to overcome the limitations of approaches focused solely on buildings. Thanks to new entities and concepts specific to linear works, infrastructure models are more coherent, readable, and usable in the various design and operational phases.

IFC 4.3 significantly improves workflows for roads, railways, bridges, and tunnels because it allows:

• to manage alignments, routes, and artworks as central elements of the model;
• to coordinate different disciplines more effectively, such as geometric, structural, and plant design;
• to maintain information continuity between design, construction, and management;
• to facilitate data exchange between different software without loss of information.

In complex infrastructure projects, these aspects translate into a greater reliability of models, a reduction of inconsistencies, and a better control of interferences. IFC 4.3 makes the IFC model a truly operational tool, capable of supporting decision-making processes and technical activities throughout the lifecycle of the work.

I-BIM for infrastructure asset management: from construction to operation

I-BIM is not limited to supporting the design and construction phases but plays a central role in the management of infrastructure assets during the operational phase. The information model becomes a reliable container of technical, geometric, and management data, usable for planning maintenance activities, monitoring the state of the works, and supporting strategic decisions.

Thanks to I-BIM, the information produced during the design phase does not get lost but remains available and updatable over time. This approach allows overcoming the traditional fragmentation of data among documents, graphic elaborations, and separate systems, promoting a more effective and conscious management of infrastructures.

In the field of asset management, I-BIM allows:

• to associate each infrastructural element with technical, performance, and maintenance data;
• to schedule interventions based on reliable and updated information;
• to reduce costs related to errors, duplications, and lack of data;
• to improve the control of works throughout the entire lifecycle.

The integration between the information model and Infrastructure Asset Management systems makes I-BIM a strategic tool for managing entities, concessionaires, and contracting authorities, allowing them to adopt a more structured and long-term oriented approach.

Use cases and applications of BIM for transport, utilities, and mobility networks

I-BIM finds concrete application in numerous infrastructural areas, where the coordinated management of geometry and information represents a decisive factor. In transport systems and technological networks, the information model allows governing extensive and interconnected works, often characterized by high operational complexity.

In the transport sector, I-BIM supports the design and management of:

• road and highway infrastructures, with control of routes, pavements, and artworks;
• railway and subway lines, with integrated management of tracks, rolling stock, signaling, and stations;
• bridges and tunnels, for monitoring structural conditions and planning interventions.

Regarding utilities and mobility networks, I-BIM allows:

• to model networks for water, electricity, and telecommunications;
• to manage interferences between underground utilities and existing infrastructures;
• to support scheduled and extraordinary maintenance activities.

In all these cases, the value of I-BIM lies in the ability to have a unique, updatable information model over time and usable by different parties, with concrete benefits in terms of control, data reliability, and reduction of operational risks.

Integration between I-BIM and GIS for territorial planning and digital twins

The integration between I-BIM and GIS systems represents a fundamental step for the management of infrastructures at a territorial scale. Infrastructural works, by their nature, develop over large areas and interact directly with the geographical, environmental, and urban context. For this reason, the BIM model alone is not sufficient to describe all the spatial and territorial relationships involved.

The union of I-BIM and GIS allows linking the information model of the infrastructure with geographical, cartographic, and environmental data, making it possible to:

• analyze the route in relation to territorial and environmental constraints;
• evaluate interferences with existing infrastructures and utility networks;
• support decisions in the planning, design, and management phases.

This integration constitutes the basis for the creation of infrastructural digital twins, that is, digital models that coherently represent the work and its real context. The adoption of digital twins in the infrastructure sector represents a significant evolution as these models update in real-time through data collected from field sensors and allow monitoring the state of the work, simulating intervention scenarios, and supporting more effective management and maintenance strategies over time.

How I-BIM supports interference detection and risk reduction in complex infrastructure projects

In infrastructure projects, the presence of numerous interconnected elements and large-scale development increases the risk of interferences between components, underground utilities, and existing works. I-BIM provides effective tools to identify and manage these critical issues already in the early stages of the project.

Through coherent and coordinated information models, I-BIM allows:

• to identify geometric interferences between infrastructural, structural, and plant elements;
• to verify conflicts between new works and existing infrastructures, including technological networks and underground utilities;
• to analyze critical issues related to construction phases, accessibility, and site safety.

Interference detection is not limited to mere geometric verification. I-BIM also allows associating technical and temporal information to the elements of the model, supporting more in-depth analyses of design and construction risks. This approach reduces the number of variations during construction, limits unforeseen events, and contributes to controlling time and costs in infrastructure construction sites. Therefore, I-BIM represents an essential tool for increasing project reliability and improving the overall quality of the work.

Interference detection and risk reduction with I-BIM

Professional Profiles and Training in Information Modeling of Infrastructures

The adoption of I-BIM has stimulated the creation of new professional profiles and the need for specific training: roles like BIM Managers and BIM specialists have become essential to ensure proper usage and efficient data management in infrastructure projects. This evolution demands contracting authorities to have adequately trained staff, not only for effective I-BIM use but also to ensure tendering aligns with the technology’s new requirements and potentials.

A certification for skills validation is therefore essential. This is carried out by specific Certification Bodies upon completion of BIM training and certification courses.

Case Studies and Practical Applications of Information Modeling of Infrastructures

A Practical Case

RFI, Italian Railway Network, expressed the need to digitize an existing railway asset, the Benevento-Cancello line, approximately 50 kilometers, for maintenance purposes, using the new IFC 4.3 standard. To address this need, a working group involving participants from RFI (Italian Railway Network), EAV (Ente Autonomo Volturno), ETS Ingegneria, University of Naples Federico II, and ACCA software was created.

A digitization process was developed using laser scanner technologies for point cloud production, drone usage for textured mesh production of stations and geolocated and 360-degree photos to navigate through.

The next step involved producing an IFC model, starting from the track geometrization obtained from the point cloud and based on the client’s specific requirements: creating a library of reusable objects and typologies, properties and typical characteristics of each entity, as per the information specifications. These decisions were made by the stakeholder and form the basis for connecting and integrating the IFC 4.3 model and the CDE with existing Asset & Facility Management systems.

The project was finalist at the buildingSMART Awards 2021 in the Asset & Facility Management category.

These projects have demonstrated how I-BIM can enhance efficiency, reduce errors, and optimize costs, leading to better infrastructure lifecycle management. Moreover, I-BIM adoption has fostered greater collaboration and communication among the various stakeholders involved in projects.

The Future of BIM for Infrastructure: Automation, Artificial Intelligence, and Predictive Digital Twins

I-BIM represents a significant turning point in the field of infrastructure construction. Thanks to the evolution of standards and digital technologies, the informational model assumes an increasingly central role in improving the efficiency, quality, and sustainability of works.

The automation of workflows allows for increased data reliability and reduced errors and inefficiencies in the various phases of the project. The integration of artificial intelligence into I-BIM processes expands analytical capabilities and supports the planning and management of infrastructure through advanced information processing.

Predictive digital twins mark a further step forward. The connection between the informational model, operational data, and monitoring systems allows for:

• assessing the behavior of the infrastructure over time;
• anticipating critical issues and degradation phenomena;
• supporting more effective and targeted maintenance strategies.

With the gradual maturation of standards and an increasingly widespread adoption of I-BIM, infrastructure projects will benefit from greater integration between design, construction, and management. The advantages will impact both the public and private sectors, with positive repercussions on the entire life cycle of infrastructures.

Read the in-depth article: “openBIM standards”

FAQ – I-BIM

What is I-BIM and what is it used for?

I-BIM (Infrastructure Building Information Modeling) is the application of BIM methodology to infrastructure and allows for the modeling, management, and analysis of works such as roads, railways, bridges, tunnels, and technological networks throughout their entire life cycle, from design to maintenance and asset management.

How does I-BIM differ from traditional BIM?

Traditional BIM is primarily oriented towards buildings, while I-BIM is specific to linear and horizontal infrastructures. I-BIM addresses the greater geometric, functional, and territorial complexity of infrastructures, integrating alignments, technical data, and management information into dedicated informational models.

What types of works are managed with I-BIM?

I-BIM is used for the design, construction, and management of transport infrastructures and technological networks, such as road and railway infrastructures, bridges, tunnels, metro lines, and utility systems, characterized by large-scale linear development.

Why is the IFC 4.3 standard essential for I-BIM?

IFC 4.3 introduces a data structure specific to infrastructures, overcoming the limitations of IFC 2×3, which was designed for buildings. Thanks to concepts like alignment, linear positioning, and stationing, IFC 4.3 allows for a more coherent and semantic representation of infrastructural works along the route.

How does I-BIM support the management and maintenance of infrastructures?

I-BIM allows for the preservation and updating over time of the information produced during the design and construction phases, making it available for asset management. The informational model supports the planning of interventions, monitoring the state of the work, and integration with Infrastructure Asset Management systems.

What is the role of integration between I-BIM and GIS?

The integration between I-BIM and GIS allows for the management of infrastructures within their geographical context, linking the informational model to territorial, environmental, and cartographic data. This integration is the basis of infrastructural digital twins and supports analysis, planning, and control of works at a territorial scale.

How does I-BIM help reduce interferences and risks in infrastructure projects?

Through coordinated information models, I-BIM enables the detection of geometric and functional clashes among infrastructure components, utilities, and existing assets. By integrating technical and scheduling data into model objects, it minimizes design changes, unforeseen issues, and risks throughout both the construction and operational phases of the project.