Publications

Real-world applications of BIM and immersive VR in construction

Year: 2024
Author(s): Mikael Johansson, Mattias Roupé
Publication Type: Journal article

The integration of immersive Virtual Reality (VR) and Building Information Modeling (BIM) has many applications within the Architecture, Engineering, and Construction (AEC) industries. In this context VR is often highlighted for its ability to convey scale and details, especially when compared to non-immersive visualizations. However, despite being an active area of research, there is currently a lack of real-world studies exploring immersive VR in a construction-oriented context. In addition, there are still technical challenges and barriers for an efficient integration, such as rendering performance and interoperability issues. This paper addresses these issues by investigating the use of immersive, single- and multi-user VR within the openBIM ecosystem. The contribution is two-fold: (a) an in-depth presentation of algorithms and technical details of a multi-user VR application for immersive visualization of large and complex BIMs and (b) an evaluation of this VR system on several real-world construction projects. In all cases the VR visualization has been directly realized from the design teams IFC-models and the multi-user sessions has been performed both co-located as well as fully remote. The results show that multi-user VR improves communication, understanding, and collaboration, and by letting staff with knowledge and experience from construction production review the project in VR, design errors and constructability issues can be identified and resolved before reaching the actual production stage. Moreover, the use of VR is helpful regarding sequencing and planning, and to identify alternative design solutions.


A Review and Case Study of Neural Network Techniques for Automated Generation of High Level-of-Detail 3D City Models

Year: 2023
Author(s): Vasilis Naserentin, Georgios Spaias, Anestis Kaimakamidis, Nikos Pitsianis, Anders Logg
Publication Type: Paper in proceeding

The growing interest in creating digital twins of cities has sparked a surge in the development of detailed 3D models. In this paper we examine the current state-of-the-art in generating high-resolution 3D models of cities using neural network techniques. Additionally, we showcase the outcomes of two case studies that demonstrate the practical applications of these techniques in 3D city model generation. The first case study focuses on rooftop segmentation using publicly available Swedish cadastral data, while the second case study explores façade feature extraction using Google Street View data.


Total BIM on the construction site: A dynamic single source of information

Year: 2023
Author(s): Oliver Disney, Mattias Roupé, Mikael Johansson, Johannes Ris, Per Höglin
Publication Type: Journal article

Digital technologies are rapidly transforming the construction industry, offering new opportunities to improve site work performance. Traditionally, site workers take information from static construction documents such as 2D paper drawings. However, in the Nordic region, a dynamic approach known as Total BIM has gained interest. Total BIM is a model-based approach to construction where BIM replaces 2D drawings as the contractual and legally binding construction document, and site workers use production-oriented, cloud-based BIM, on mobile devices to extract construction information. By having a dynamic single source of information, site workers face new demands as they independently extract construction information directly from BIM. This paper investigates the impact of Total BIM on site work methods through four real-life case studies, site visits, workshops, seminars and semi-structured interviews. The findings indicated that Total BIM provided site workers with a more dynamic construction process where the mobile BIM-viewer software became a central communication and management platform. Key digital Total BIM features were investigated that site workers used to perform new work methods, including measuring, filtering, visualizing, communicating, checklists, and requests for information. By using Total BIM instead of static 2D drawings, site workers interacted dynamically with BIM on mobile devices, changing the process of how work was implemented on the construction site. The practical implications of these findings can be used to support the on-site implementation and strategy work of Total BIM. Furthermore, this paper contributes practical concrete examples of on-site Total BIM use and addresses issues commonly found in state-of-the-art BIM projects.


Towards a framework for railway network assets management based on BIM/GIS integration

Year: 2023
Author(s): Mattia Mangia, Carla Di Biccari, Mattias Roupé
Publication Type: Paper in proceeding

Complex infrastructures such as railway networks face increasing challenges related to resource allocation, external events, constraints, and demands. Therefore, it is crucial to optimize the Asset Management (AM) phase to ensure the value and functionality of the assets. The integration of Building Information Modelling (BIM) and Geographic Information Systems (GIS) can support this phase, but it can only yield benefits with a comprehensive approach that considers and addresses the specific needs and resources of the assets and their AM organization. The main benefits include improved data management, manipulation, information visualization and optimized resource allocation. This study describes an intermediate step towards developing a BIM/GIS integration framework for AM that can guide both researchers and practitioners. The framework aims to bridge theory and practice by incorporating insights from literature reviews and case studies. Its main objectives are to provide a comprehensive multi-stakeholder view and methods for effectively integrating BIM and GIS in this context. To develop the framework, the study employed focus groups, interviews, and practical BIM/GIS tests, which provided insights reported in this article. Furthermore, the study provides research directions for effective BIM/GIS integration in infrastructure AM.


A Grid-Based Methodology for the Assessment of Timedependent Building Damage at Large Scale

Year: 2023
Author(s): Pierre Wikby, Ezra Haaf, Ayman Abed, Lars Rosen, Jonas Sundell, Minna Karstunen
Publication Type: Preprint

Leakage into underground constructions can result in groundwater drawdown and time-dependent settlements in soft clay. In urban areas with spatial variability in geologic stratification, groundwater conditions and soil compressibility, differential settlements may occur, causing damage to buildings. Current methods for damage assessment tend to rely on 1D empirical formulations for settlement prediction, which are not representative for drawdown-induced settlements in heterogeneous environments. In this paper, 2D deformations were first computed using a coupled hydro-mechanical finite element model, simulating the time-dependent pore-pressure reduction in a confined aquifer. An advanced constitutive model was used to account for both creep and consolidation. The results were employed to train a metamodel, which considered spatial variability in stratification, resulting in time-dependent vertical settlements computed as a grid. Based on these results we propose an approach to integrate spatially distributed, grid-type settlement data into building damage assessments at city scale. The approach was applied to 215 buildings in central Gothenburg, Sweden by simulating scenarios of 10 kPa and 40 kPa pore pressure drawdown in the lower (confined) aquifer. The proposed methodology offers an effective way for damage assessments at a large scale, so that further investigations and mitigation measures can be targeted to the buildings at highest risk for damage.


Evaluation of social facilities coverage: A case study of Sofia city

Year: 2022
Author(s): Stoyan Boyukliyski, Dessislava Petrova-Antonova, Sanjay Somanath
Publication Type: Paper in proceeding

In order to aid the decision making process related to the provision of public services as to maximize the benefits for society, it is crucial to evaluate the current social facilities demand in terms of spatial distribution and access. The paper aims to solve this problem by proposing a method for automated assessment of the coverage of public services within an urban region using a capacitated graph. The methodology abstracts residential buildings into demand nodes and public service buildings into supply nodes within a graph and then uses shortest distance calculations in order to balance the two, while prioritizing residential buildings based on distance. The paper is focused on creating a general pipeline that can be used on any type of public services, as long as a certain geospatial and demographic data are available. The method is described without referencing specific tools, but focusing on the general procedure. The procedure is then applied to the whole city of Sofa, focusing on assessing the coverage of kindergartens using the 15 minutes walking distance, followed by a brief discussion of results.


Pathways towards carbon neutrality: A participatory analysis of the Gothenburg’s energy plan

Year: 2022
Author(s): Daniela Maiullari, Alvar Palm, Holger Wallbaum, Liane Thuvander
Publication Type: Paper in proceeding

Among International Energy Agency members, Sweden is one of the upfront countries in implementing energy policies to achieve zero net emissions. Despite having the lowest share of fossil sources in its primary energy supply, becoming carbon neutral by 2045 is a challenging target. To meet the national goal, cities’ roadmaps and strategic plans have a leading role in facilitating the implementation of energy efficiency measures and renewable production systems. However, succeeding in city energy transitions requires envisioning and understanding of risk and vulnerability levels of the new socio-technical energy system. This study presents a review of the City of Gothenburg’s Energy Plan 2022-2030 and discusses potential challenges
for its implementation. Based on a document study, stakeholder workshop, and interviews the research identifies four key aspects: i) the coordination between energy and urban planning, ii) the future stability of district heating and cooling, iii) the balance in electrification of the buildings and transport, iv) communication and tools in decision-making processes. Finally, the study suggests new measures that should be allocated in the plan to guarantee the development of instruments and analysis for addressing the identified challenges.


Using the Octree Immersed Boundary Method for urban wind CFD simulations

Year: 2022
Author(s): R. Mitkov, M. Pantusheva, Vasilis Naserentin, P. O. Hristov, Dag Wästberg, F. Hunger, Andreas Mark, D. Petrova-Antonova, F. Edelvik, Anders Logg
Publication Type: Paper in proceeding

This paper describes the initial steps in a larger effort to perform verification and validation (V&V) of wind simulations in an urban environment. The presented work uses data from wind tunnel experiments on a simplified urban area to assess the performance of the steady-state RANS octree immersed boundary flow solver IBOFlow (R). Verification and validation activities are indispensable in computational modelling, because they address the issue about the trustworthiness of models directly. This is particularly so in the modelling of complex systems such as urban environments. The results of the early V&V work are presented, together with a discussion on different aspects of the experimental and modelling settings. A key contribution this work, which is planned as a first in a series of V&V publications, is the identification of concrete future actions to address the issues of trust in urban wind model predictions. Copyright (C) 2022 The Authors.


Digital Twin Cities: Multi-Disciplinary Modeling and High-Performance Simulation of Cities

Year: 2022
Author(s): Anders Logg, Vasilis Naserentin
Publication Type: Magazine article

The digital twin concept has virtually exploded in recent years, as
evidenced by the exponentially growing number of scientific articles
making use of the concept.

The concept originates from the manufacturing industry where the use
of CAD models enables the creation of exact digital replicas of
components and products. The earliest use of the term dates back to
2003 and is often credited to Grieves and Vickers, but earlier references to
the concept can be found; certainly, the understanding that mathematical
and, more recently, digital models of physical systems are of enormous
importance to both science and engineering dates back centuries.

The concept has since spread from the manufacturing industry to other
disciplines, such as agriculture, electricity, vessels, manufacturing,
construction, cities, healthcare, aerospace, waste, water, transport,
and automotive.

In this short note, we present an overview of the use of digital twins
in the built environment; that is, digital twins of cities and
buildings. In this context, the term digital twin is closely linked to
the concept of smart cities (or smart buildings). The
relation between a digital city twin and a smart city is that the
digital twin is the enabling technology for making a city smart. Even
if a digital twin is not a sufficient condition for making a city
smart, it is a necessary condition.


Mot koldioxidneutralitet: Göteborgs stads energiplan

Year: 2022
Author(s): Liane Thuvander, Daniela Maiullari, Holger Wallbaum
Publication Type: Magazine article

För att uppnå det nationella målet att bli koldioxidneutral till år 2045
spelar städernas färdplaner för energiomställning en viktig roll inte minst
genom energiplaner. Hur kan dessa effektivt implementeras och vilka är
de potentiella flaskhalsarna?


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