A BIM-Enabled Workflow for the Rehabilitation of Heritage Steel Bridges
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe text examines the use of BIM in the rehabilitation of historic steel bridges, addressing structural and conservation challenges. It proposes digital workflows to improve information management, create digital twins for predictive maintenance and develop an IDS scheme. It integrates structural assessments and reinforcement strategies into BIM, promoting more efficient decision-making and heritage conservation.
The manuscript is well structured and methodology is clear. Results are well presented.
However, few changes are needed.
• Abstract should be re-structured. The purpose of the research takes up too much space at the expense of the context. It would be appropriate to reduce the explanation of the methodology in order to expand the context. The anticipation of the results and the conclusion are well done.
• In the “introduction section” The integration of BIM and GIS should be explored to improve the study. Effective integration between BIM and GIS could optimize the management and monitoring of infrastructure, such as bridges, in a more comprehensive manner. An example could be: https://www.mdpi.com/2076-3417/14/23/11171.
• In section 2, recent studies dealing with the use of BIM for infrastructure management should be explored.
• Although concepts such as OIR, AIR and PIR are introduced, it would be useful to provide a concrete example of each type of information requirement to clarify how they affect each stage of the project.
• Advanced techniques such as laser scanning and photogrammetry for data collection are mentioned. It would be useful to explore how these technologies integrate with the digital BIM workflow, not only for data collection but also for simulation and prediction.
• Detailing how post-rehabilitation monitoring (with the use of IoT sensors) helps maintain an up-to-date model, allowing for continuous improvements in future rehabilitations.
• Although the text discusses the validation of information, it might be useful to expand on the part concerning quality metrics for validation and how the different validation phases integrate with project design and execution. For example, the quality of information gathered during the design phase could influence decisions during construction or maintenance.
• It would be useful to conclude with a reflection on the importance of long-term visions in information management, especially in contexts such as historic bridges, where modern techniques can ensure optimal preservation and management over time.
Author Response
Abstract should be re-structured. The purpose of the research takes up too much space at the expense of the context. It would be appropriate to reduce the explanation of the methodology in order to expand the context. The anticipation of the results and the conclusion are well done.
The abstract has been revised to better balance the context and the purpose of the research. Specifically, we have expanded the context to emphasize the challenges and significance of rehabilitating heritage steel bridges, including their historical and structural complexities, and the transformative potential of digitalization and BIM workflows in addressing these issues.
In the “introduction section” The integration of BIM and GIS should be explored to improve the study. Effective integration between BIM and GIS could optimize the management and monitoring of infrastructure, such as bridges, in a more comprehensive manner. An example could be: https://www.mdpi.com/2076-3417/14/23/11171.
We would like to thank you this suggestion. Further information was integrated into the section citing a series of recent research. Please refer to lines 40 – 61. Additional information was also provided in section 2.3.
In section 2, recent studies dealing with the use of BIM for infrastructure management should be explored.
A new sections, “2.3 BIM for infrastructure management” was introduced, further explaining BIM use for infrastructure management.
Although concepts such as OIR, AIR and PIR are introduced, it would be useful to provide a concrete example of each type of information requirement to clarify how they affect each stage of the project.
We agree that practical examples can enhance understanding and bridge the gap between theory and implementation. However, it is important to note that currently, most (avoiding to say all) authorities lack a functional BIM system, including foundational elements like OIR, AIR, and PIR. In some specific projects, an Employer's Information Requirement (EIR) is developed, typically poorly defined, limiting the overall effectiveness of BIM processes.
To address this gap, subsequent sections of the paper provide a generic set of requirements for each document—OIR, AIR, and PIR aiming to guide authorities in defining and implementing these critical components of a BIM framework. By offering this structured foundation, the paper aims to support the gradual adoption of functional BIM systems and improve the alignment of project objectives with information requirements.a
Advanced techniques such as laser scanning and photogrammetry for data collection are mentioned. It would be useful to explore how these technologies integrate with the digital BIM workflow, not only for data collection but also for simulation and prediction.
Additional information was provided to underline the added value of BIM for simulation and prediction. The section at lines 433 – 447 was added to support this.
Detailing how post-rehabilitation monitoring (with the use of IoT sensors) helps maintain an up-to-date model, allowing for continuous improvements in future rehabilitations.
Additional information, please refer to lines 474 –494d was added.
Although the text discusses the validation of information, it might be useful to expand on the part concerning quality metrics for validation and how the different validation phases integrate with project design and execution. For example, the quality of information gathered during the design phase could influence decisions during construction or maintenance.
Additional information was added to address the mentioned topic. Please refer to lines 695 – 720.
It would be useful to conclude with a reflection on the importance of long-term visions in information management, especially in contexts such as historic bridges, where modern techniques can ensure optimal preservation and management over time.
The revised conclusion reflects the importance of adopting long-term visions in information management, particularly for historic bridges. By emphasizing the integration of modern techniques such as BIM and digital twins with proactive strategies, the rewritten section highlights how these tools support optimal preservation, efficient resource allocation, and sustainable management over time. This approach ensures that both functional and cultural values are preserved for future generations, aligning with the intent of the comment.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript is focused on the use of Building Information Modelling (BIM) characterised for historical steel bridges. The manuscript is well-written and clear. However, it lacks in novelty contents and appropriate revisions are needed.
It seems that the methodology section 3 discusses issues and protocols which can be adopted for whatever bridge type. This does not reflect the title in which the authors claim that the focus of the work is on heritage steel bridge. This section should be revised by commenting issues characterising the application of BIM for historical steel bridges.
The authors generally mention historical steel bridges, while not reporting any definition of the investigated bridge type. Indeed, historical steel bridges can exhibit different structural schemes with beam-type or truss-type superstructures, and can be characterised by various substructure schemes. Please clarify.
The authors should focus on the geometric or structural model implementation for specific historical bridge type. Indeed, the implementation of geometric models in BIM environment can be challenging for not-conventional bridge types such as steel truss bridges (composed by many elements for which specific information should be inserted).
The authors should discuss the issue of connecting BIM-type models and finite element models for structural analyses.
The title of section 2.1. should be revised. Indeed, such section discusses not only bridge inspection strategies, but also monitoring and management strategies. In addition, this section should report references for using AI and drones for bridge inspections (L195) (e.g. https://doi.org/10.1016/j.autcon.2018.06.006). Also, satellite-based methods should be listed as new technologies for bridge monitoring (https://doi.org/10.1155/2024/8978782)
Author Response
The authors would like to thank the reviewers for your insightful feedback regarding our paper. Please find below our reply to each of your comments.
It seems that the methodology section 3 discusses issues and protocols which can be adopted for whatever bridge type. This does not reflect the title in which the authors claim that the focus of the work is on heritage steel bridge. This section should be revised by commenting issues characterising the application of BIM for historical steel bridges.
When it comes to information management, many of the steps employed for information management are similar to all bridges, unrelated to the material. Nevertheless, considering our extensive experience in steel bridges and limited experience with other kind of structures, we’ve decided to focus more on steel bridges and do not tackle the general case, since we might miss some important details specific to concrete, timber or other kind of structures.
The authors generally mention historical steel bridges, while not reporting any definition of the investigated bridge type. Indeed, historical steel bridges can exhibit different structural schemes with beam-type or truss-type superstructures, and can be haracterized by various substructure schemes. Please clarify.
When it comes to information management, many of the steps employed for information management are similar to all bridges, unrelated to the material. Specific information requirements are part of the AIR and PIR documents, which cannot be derived in detail without the support of a bridge custodian contribution. The bridge shape, structural details and many more are part of the 4th chapter, Case study for the Savârșin heritage steel bridge.
The authors should focus on the geometric or structural model implementation for specific historical bridge type. Indeed, the implementation of geometric models in BIM environment can be challenging for not-conventional bridge types such as steel truss bridges (composed by many elements for which specific information should be inserted).
The authors focus on the information framework that facilitate the information flow, from design to operation. The main objective is to underline the importance of ‘starting with the end in mind’, while having a clear information process from information requirements definition, information development, validation and information use. The model transfer from structural analysis to detailing, or from an initial AIM model to a PIM model is, in itself, a large topic that can be addressed independently. On this line, the article does not go into details related to the geometric or structural model of the bridge.
The authors should discuss the issue of connecting BIM-type models and finite element models for structural analyses.
We appreciate the suggestion to discuss the connection between BIM-type models and FEM for structural analysis, as it is indeed a crucial aspect of digital workflows in bridge rehabilitation projects. The issue of interoperability and information transfer between applications at various stages is a significant topic and a current challenge, particularly with regard to Industry Foundation Classes (IFC) and BIM Collaboration Format (BCF) standards. These file formats, while widely used, often encounter limitations in representing detailed structural models and facilitating seamless data exchange across platforms. This challenge is acknowledged and briefly addressed in Section 3.4 of the paper, where the Information Delivery Specification (IDS) is introduced. The IDS aims to establish a clear and standardized approach to defining and validating data exchanges, ensuring that both geometric and non-geometric data required for FEM are effectively integrated within the BIM environment.
The title of section 2.1. should be revised. Indeed, such section discusses not only bridge inspection strategies, but also monitoring and management strategies. In addition, this section should report references for using AI and drones for bridge inspections (L195) (e.g. https://doi.org/10.1016/j.autcon.2018.06.006). Also, satellite-based methods should be listed as new technologies for bridge monitoring (https://doi.org/10.1155/2024/8978782)
The section title was change to “Traditional methods and emerging technologies for bridge inspection, monitoring and management” to better reflect the content. It was also completed with additional information related to suggested work (please refer to lines 249 – 268)
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article has been revised to provide a more complete and accurate representation of the topic. The addition of new data provides a clearer picture of the current state of research in this field. References have been implemented. All these changes together make the article ready for publication.
Reviewer 2 Report
Comments and Suggestions for AuthorsNo further revisions are needed.
