Building information modelling in infrastructure projects
14 March 2017
Arup has recognised that the way we carry out our business is constantly evolving, particularly with the now widespread adoption of building information modelling (BIM) processes. The emergence of advanced modelling technologies offer us the ability to deliver high quality, information rich deliverables to our clients as well as greatly improving the way we interface with all other project stakeholders.
In recent years, BIM has become a fundamental strategy and the status quo in the vertical world of buildings. However, the adoption of this new technological approach in infrastructure has been significantly slower.
The challenge has been laid down: to take our multidisciplinary approach to the next level, creating an all-encompassing data base that facilitates seamless collaboration and interfaces, spans across the full suite of design phases and engages all partners in the design, construction and operation and maintenance processes across large multidisciplinary infrastructure projects.
This article explores the use of BIM in infrastructure, the challenges and opportunities and presents the key solutions and techniques Arup have been developing across our projects to meet these challenges and develop these opportunities.
What is BIM?
BIM is well established in Arup and is now being applied to project delivery at all stages on a significant number of our projects. We have been modelling in 3D since the late 1980s.
However, in order to accurately evaluate the challenges that are being faced when applying BIM in Infrastructure, it is worth setting out the following key guideline: BIM is not a software or a 3D model, but rather BIM is the process of efficient integration of 3D models, design tools and other data rich components to increase collaboration and efficiency in the design and delivery process at all stages of our projects.
A significant range of specialist software is required in infrastructure due to the number of specialist disciplines involved in the delivery of infrastructure projects. Disciplines such as highways, bridges, rail, geotechnical, GIS and maritime each use their own specialist software.
The success and efficiency of BIM therefore relies on the interoperability of the software.
The software packages need to be compatible in order to facilitate collaboration, the preparation of confederated models, spatial co-ordination and design efficiencies. Our experience indicates that full interoperability between the various packages can be a significant challenge.
There are ongoing improvements in the interoperability of the software that we use. Given the speed of adoption of BIM, one must assume that this improvement will and must continue. However, there can be reluctance from specialist disciplines to embrace new software to meet the ever-changing requirements of BIM. This is a mindset that must be changed to facilitate true progress.
A significant challenge for infrastructure projects is the modelling of complex geometry in linear alignments. In building engineering, the complexity can often result from having multiple objects input by multiple disciplines.
However for linear infrastructure such as rail, highways, tunnelling and bridges, the complexity can result from having a smaller number of individual but complex elements with topology changing rapidly over the alignment. Rail and often highway alignments have varying radius curved alignments while bridges can have 2D decoupled elevation and plan axis geometry with cross sections changing over the alignment to address rollover and super elevation requirements.
Addressing the challenges
Most software vendors are adapting quickly to address these challenges, however tools maturity for infrastructure projects still remains lower than that of buildings. As specialist disciplines find the best software to meet their individual needs the challenge still lies in the collective search for efficient interoperability between software used by each specialist discipline within often large multidisciplinary infrastructure projects.
As design teams and contractors are up-skilling to take advantage of the benefits of BIM the challenge is to bring our clients on board. The perception around technology use in engineering is that things can be done faster. While technology tools allow efficient manipulation and adaptation of models once set up, there is a lack of appreciation of the upfront time to develop the content and templates within these data rich models.
This needs to be effectively communicated to our clients and a clear understanding of the scope of the project developed from the outset. We must keep in mind that the benefits of BIM in the later stages of projects has to be somewhat balanced by the longer time input required at the earlier stages of a project.
The volume of digital information that is available through the BIM process and ensuring that this is appropriately controlled and effectively shared brings its own challenges.
A fundamental requirement of BIM is to establish a Common Data Environment (CDE) that acts as a platform to facilitate the collection, storage and dissemination of information from all areas of the project. This leads to a requirement for a mindset change in our teams regarding how our projects are administered.
With the above in mind, it is clear that there is a requirement for significant training and up-skilling for teams to effectively work in a BIM environment.
Solutions and opportunities
As with all challenges, there are solutions. At Arup, we are building on our multidisciplinary approach to all projects by developing processes to enhance connectivity between the various activities within the BIM environment. With a robust CDE at the core, the essence of successful BIM implementation is to complete the virtual cycle through the design phases from concept to the operations and maintenance stages with a minimal amount of information lost, duplicated or having to be recreated.
This applies to all aspects of the design process, from setting out the spatial geometry, details, analysis models, costing and design and construction schedules. The following examples demonstrate how we have been developing these processes on a project by project basis to enhance our offering to all phases of the project.
Design and analysis efficiency: Recent projects such as a Canadian Light Rail project have required 3D modelling of complex rail alignments, elevated bridge components, station architecture, structures and MEP. With the alignment extending over 13km through a busy urban environment with heavily congested services the selection of alignment needed to evolve as information and specialist input became available.
The choice of modelling tools was based on the need to ensure easy transfer of information, interoperability between the disciplines, flexibility to easily accommodate change and the ability to feed into the analysis that was being run in tandem. To avoid being restrictive on what software we would use to develop alignments, structural models and analysis models we looked to develop tools to allow the easy transfer of information between the specialist models.
Bentley Projectwise was used as the robust CDE where all the project information was stored. The alignment, containing clothoid spiral curvature to satisfy rail engineering requirements, was developed using Autodesk Civil 3D with Autodesk Revit chosen as the modelling tool for the elevated bridge, station structure, architecture and MEP. Specialist bridge analysis software MIDAS Civil and Arup In-house Oasys GSA were chosen to analyse the bridge and station structures respectively.
The key challenge was to ensure that each model could be set up parametrically to allow efficient adaptation to changes in the alignment. We adopted a mixture of 3rd party scripting tools such as Excel VBA coding and Dynamo to enable the transfer of data between specialist 3D models and analysis models. By creating clever VBA families of modules operating in a hierarchy to pre-process the information we set up a robust, flexible and seamless virtual cycle within the BIM environment.
Spatial co-ordination and clash detection: One of the major benefits that fully implemented BIM brings both to the design teams and to the client is the spatial coordination and clash detection opportunities. By combining the models from the various disciplines in a federated model, full spatial coordination can be carried out throughout the design stages. We have used Navisworks to combine architectural, structural and MEP models on significant infrastructure projects such as underground metro stations. On these projects the design team could produce and review clash reports on a weekly basis. This allowed specialist disciplines to c0-ordinate layouts in real time and set up action plans for working towards a clash resolvable final design for handover to our client.
On complex urban rail projects, we have run clash detection models to combine 3D models of existing and proposed utilities with the foundations of the proposed alignment in order to facilitate coordination of utilities relocation. We have also worked with our contractor clients to space proof areas of congested reinforcement by modelling concreting pipes and tendon ducts to inform constructability decisions before going to site.
Real-time modelling and asset management
The benefit of the upfront time invested to set up the data rich content is the ability to expand the 3D model to 4D to include construction schedules to aid efficient construction sequencing and planning. The ability to generate powerful tools for visualisation and simulation provides endless opportunities to the client to reduce interface risk and increase community engagement.
On the Rastatt Tunnel project, a 4.27kM twin tube tunnel in Germany, we were involved in the development and review of the BIM implementation plan. The plan adopted a “build digitally first” approach by combining the data rich inputs with construction planning to allow the client achieve to early community engagement and reduce the interface risks associated with large infrastructure works of its kind.
Referred to as the 5D element of BIM, cost management can benefit hugely from a joined up, collective approach. On large infrastructure projects such as metro projects we have incorporated quantity evaluation and cost estimation as part of the suite of services offered to the client. Leveraging the information rich models used in the design process we have the ability to extract quantities for cost estimation and management at all stages in the design process. On large scale infrastructure projects this has provided us with the ability to give real time cost projections to the client.
The nature of infrastructural assets is that these are typically unique in terms of design, will have a long life expectancy, require a multi-disciplinary input for design and operation, and can even change in function over time.
ISO55000 (Asset Management System) and its predecessor, PAS55, are two international standards which set clear Plan-Do-Check-Act management mechanisms. These standards aim to realise value from assets in the achievement of an organisations objectives. One of the key elements of this management process is the build-up of information.
As an information-rich tool, BIM has the ability to provide significant efficiencies for the whole life consideration of these assets, and not just at the design and construction life stages. To date BIM 3D (Design), 4D (Scheduling) and 5D (Estimating) are currently more prominent, however 6D (Sustainability) and 7D (Operations) are starting to gain greater traction.
By integrating BIM with Computer Maintenance Management Systems (CMMS) or similar, it can become a powerful management and future planning tool for its owners / users. This allows better informed decisions to be made earlier, thus generating greater cost efficiencies.
While BIM implementation in infrastructure has its challenges, adoption by software vendors, engineering consultancies and contractors alike is facilitating growth of its use. As the infrastructure world follows the Building Sectors our clients are starting to see the real benefit of BIM implementation on their projects. At Arup we have found that the development of staff is key to the effective implementation of this digital work delivery process.
As can be seen from the suite of software available and the requirements to share information between disciplines, staff need to be adaptable to using multiple software packages. The demarcation between the draftsperson and engineer is becoming more blurred. We are certainly enjoying the challenge and witnessing the benefits we see in bringing BIM to our clients as we make it a fundamental part of our infrastructure Projects into the future.http://www.engineersjournal.ie/2017/03/14/building-infrastructure-modelling-infrastructure/http://www.engineersjournal.ie/wp-content/uploads/2017/03/BIM1-1024x580.jpghttp://www.engineersjournal.ie/wp-content/uploads/2017/03/BIM1-300x300.jpgCivilArup,BIM,construction,infrastructure,structures and construction