Early-stage BIM for CERN s Future Circular Collider studies

Transcription

1 12 TheStructuralEngineer Feature for CERN s Future Circular Collider studies Yung Loo, Arup Matt Sykes, Arup Craig Sturzaker, Arup John Osborne, CERN Charlie Cook, CERN Glossary Back end Beta development Big data Cloud-based Digital elevation model Front end Genetic algorithm Georeferencing Graphical user interface (GUI) Heat map Open-source software Optioneering Representational state transfer (REST) Relational database Technology stack The technology that supports the front end of a website (e.g. a server and database) The second phase of software development in which the software features are complete but likely to contain a number of bugs. Beta testing precedes a full release of the software A broad term for data sets so large or complex that traditional data processing applications are inadequate Applications, services or resources made available to users on demand via the internet A digital model or 3D representation of a terrain s surface (e.g. Earth) created from terrain elevation data A presentation layer or interface between the user and the back end of a software application A search heuristic that mimics the process of natural selection. This is routinely used to generate useful solutions to optimisation and search problems The process of associating an object (e.g. physical map or raster image) with locations in physical space A type of interface that allows users to interact with electronic devices through graphical icons and visual indicators, as opposed to text-based interfaces, typed command labels or text navigation A graphical representation of data where the individual values contained in a matrix are represented as colours Computer software with its source code made available with a licence in which the copyright holder provides the rights to study, change, and distribute the software to anyone and for any purpose An appraisal of the design, specification and management of alternative options A software architecture style consisting of guidelines and best practices for creating scalable web services A digital database which organises data into one or more tables (or relations ) of rows and columns, with a unique key for each row The layers of components or services that are used to provide a software solution or application Introduction Building Information Modelling (BIM) is a collaborative way of working, underpinned by the digital technologies which unlock more efficient methods of designing, creating and maintaining our assets 1. The UK government has mandated the use of Level 2 BIM on all public sector projects by 2016, and published its Level 3 BIM strategy in February In line with these aims, Arup has developed a BIM tool with CERN (European Organization for Nuclear Research) for its Future Circular Collider (FCC) 3 project. The tool has been specifically developed to aid the decisionmaking process for the conceptual planning and siting studies of the potential particle collider tunnel. Its use for this project illustrates how the data-centric collaborative and efficiency aims of BIM are achievable, particularly at the early stage of a project, where there is the greatest potential to guide key decisions. At CERN, physicists and engineers are probing the fundamental structure of the universe. They use the world s largest and most complex scientific instruments to study the basic constituents of matter the fundamental particles. The particles are made to collide together at high energy, close to the speed of light. The process gives the physicists clues about how the particles interact, and provides insights into the fundamental laws of nature. The Large Hadron Collider (LHC) is the world s largest and most powerful particle accelerator. It first started up in 2008, and remains the latest addition to CERN s accelerator complex. The LHC consists of a 27km ring of superconducting magnets to guide the stiff proton beams around the quasi-circular path of the machine, and through accelerating structures which boost the energy of the particles at each turn. Particle physics takes the long-term view. Originally conceived in the 1980s, the LHC took another 25 years to come into being. This accelerator, which is unlike any other, is just the start of a programme which is expected to run for another 20 years. Even now, as the recent restart of the LHC begins the next long period of operation, detailed plans are being hatched for a large-scale upgrade to increase luminosity and thereby exploit the LHC to its full potential. The HL (High Luminosity) LHC is CERN s top priority and will increase the number of collisions accumulated in the experiments by a factor of 10 from 2024 onwards. At the same time, CERN has launched a study for the next-generation proton-proton and electron-positron high-energy frontier particle accelerators. The FCC would be situated in the Geneva area, across the borders of France and Switzerland, and is planned to be housed within a tunnel up to 100km in circumference nearly four times the size of the present LHC. The FCC would use advanced superconducting magnets operating at twice the field or more of those in the LHC. Combining a stronger bending field and larger radius of curvature would thus allow a gain of an order of magnitude on particle energy with respect to the LHC.

2 13 S Figure 1 Tunnel Optimisation Tool (arbitrary positioning of FCC shown) goal for TOT was to create a system that enables maximum value to be extracted out of this early project information, ensuring that the data can be used to their fullest potential to inform the decision-making process. A key part of the early stage of the project has been to determine the alignment corridor for the tunnel. This is a crucial part of any tunnelling project, but particularly so for a tunnel of this length and scale, whereby interfaces and the possible impacts on these are potentially even greater and more varied than usual. These include aspects such as the geological conditions, surface constraints and the particular functional requirements of the collider tunnel. These must all be considered, with attention paid to their individual requirements, when determining an optimum alignment corridor. To incorporate these variables and to facilitate the decision-making process, the project team developed the Tunnel Optimisation Tool (TOT). TOT is an earlystage BIM tool, which integrates the key project requirements and data sets into a single geospatial model to form a userfriendly, web-based dashboard. This allows project team members to work within a common data environment and interrogate the key decision-making interactions in a coordinated and objective manner. The early stage of any project is particularly important in ensuring that the foundations are laid for the project to be steered in the right direction. Critical decisions are made at this stage, and their repercussions are felt throughout the whole lifecycle of the project, from design through to operation and, ultimately, decommissioning. It is at this early stage of a project that the least amount of data exists, yet it is at this point that some of the most important decisions are made decisions on the eventual constructed design, and on the feasibility of the project as a whole. The Tunnel Optimisation Tool A significant amount of information resides within early project data; however, this is not conventionally mined and utilised to its full potential when carrying out site feasibility and tunnel alignment studies. This is due to constraints of time, process and the status quo, which restrict traditional approaches to only fully utilising subsets of the available information. TOT was created to overcome these conventional constraints by designing a smarter system that was able to extract maximum value out of existing data. In optioneering an alignment, conventional approaches follow a broadly linear and manual process to digest the data. This considers different influences and variables separately, before bringing them together to select an alignment. Although this process follows a rigorous methodology and approach, by virtue of the process and tools at hand, there is reduced capacity for a wider appreciation of the full array of possibilities and interactions. This can lead to significant rework and reiteration if information changes. TOT reworks this approach and disregards this linear process. By bringing all the information together in one place, TOT analyses and presents all the relevant information so that decisions can be identified and considered holistically. The information is presented on a web-based dashboard which is accessible to all project Table 1: Key benefits of BIM for Tunnel Optimisation Tool Extraction of maximum value from early project data Streamlining of broadly linear and manual approach to tunnel alignment optioneering Objective, repeatable analysis and comparison of options. Allows for data and knowledge increases and assumption changes, including import/export of options Provides common data environment, single source of truth, and data/user management system for project s global collaborators Cloud-based, integrated, single BIM model, future-proofed for improvements in data maturity and level of detail Open-source development provides flexible and bespoke functionality User-friendly visual interface provides invaluable communication tool and level of detail which is accessible for all project participants and stakeholders Clash detection regional scale: incorporating ground engineering and tunnel system requirements

3 14 TheStructuralEngineer Feature Figure 3 Beta development of 3D model integration within TOT members through a web browser. The front-end display of TOT is illustrated in Figure 1, with its key benefits highlighted in Table 1. A particularly powerful function of TOT is this intuitive user interface which integrates all the project data. This allows any project member to manipulate and analyse an alignment option in 3D space. There is dynamic update of the results of the chosen option, including instant update of the surface and subsurface constraints that the alignment passes through, automatic collation of decision-making outputs, and warning triggers should certain requirements or limits be exceeded. TOT not only ensures that these requirements and constraints are all considered effectively, but the data-centric and graphic nature of the system ensures that analysis and optioneering can be continuously and reliably iterated and clearly communicated. This communication aspect is extended to the nature of the system itself TOT is a cloud-based system, allowing global collaborators to access and share models with other users through the system, and also upload and download bespoke options and analysis results for offline use. TOT streamlines the workflow processes and coordinates the different stakeholder requirements of the wider project team into one system. The overlap of requirements S Figure 2 MacLeamy s curve (adapted from CURT, ) and constraints between the physics, geotechnical engineering and tunnel engineering interests is all managed and analysed through TOT. This coordinated approach allows for standardisation of comparison and multivariate analysis of the competing parameters and priorities. Riskand cost-based metrics are subsequently applied to these options to aid in the determination of an optimum solution. Value principle The value of BIM is in the data that it manages and the efficiencies in process, collaboration and communication which it provides throughout the project lifecycle. These principles are famously represented in MacLeamy s curve 4 (Figure 2). The curve illustrates the opportunities to make the most influential design and cost differences reside at the start of a project. By embracing integrated and collaborative processes through BIM, decision-making processes can be shifted earlier in the project lifecycle, leading to cost savings and efficiency gains. TOT represents a novel example of the implementation of this through the early adoption of BIM on a large tunnelling infrastructure project. Doing so aids the decision-making process while ensuring that the savings and advantages, as illustrated by MacLeamy, can be realised. Technology stack The backbone to TOT is the data which it analyses and the analytics which it applies to these data. The front end to TOT provides access to these analytical functions and visually represents the data through a user-friendly graphical user interface (GUI). The tool has been developed within an open-source technology stack to ensure a high level of flexibility, accessibility and inter-operability between the project collaborators. The stack consists of a front-end web application, a back-end relational database, and a communication and security framework between. Broken down this divides into: Front end An HTML and JavaScript web application, which acts as the access point to the analytical functions and data stored within the database. The GUI is accessed through a secure sign-on facility. Back end An open-source, spatially enabled, relational database. A number of stored procedures have been developed which perform the analytical functions that determine the location of the tunnel alignment and its

4 15 interaction with the other input data sets in a 3D space. Communication and security framework A number of representational state transfer (REST) services are used to expose the data and analytical functions stored within the database. Providing access to the database in this fashion allows the data to be consumed through multiple applications not just the web browser. This enables access through linked systems and other web applications. Determining tunnel alignment corridor To understand the benefits of TOT, it is necessary to appreciate the components that determine an optimum tunnel alignment. Key information for consideration includes: functional requirements of the tunnel system geological and topographic constraints surface constraints These all feed into engineering impacts such as the tunnelling design and methodology itself, environmental issues, and programme and costs. Functional requirements of tunnel system First and foremost, the tunnel alignment needs to be designed to meet the requirements of the system. Typical tunnel requirements may include the radius of curvature of a curved tunnel section, or a maximum gradient to the alignment. Such requirements are needed of the FCC particle accelerator tunnel as well. But there are further project-specific requirements in addition to these. These need to account for the tunnel construction and conventional facilities requirements, but also their impact on meeting key physics requirements, such as those of the cryogenic modules and particle beam delivery systems. In the case of the FCC, the crosssectional axis of the tunnel alignment needs to stay within a plane (the main reason for this is to minimise dispersion of the particle beam), as opposed to following Earth s curvature. This plane could, however, be sloping with respect to the local horizontal, i.e. the tangent to Earth s ellipsoid. There are also constraints related to the interaction of the FCC and the existing LHC, which could be used as a pre-injector to the FCC. These are necessary to ensure that appropriate tolerances are achieved for functionality of cryogenic systems and magnet technology in the associated beam transfer connection tunnels. Various ring-shaped tunnel alignments are also under consideration from circular, to quasi-circular, to oval. These consist of a number of sections, which follow curvatures defined by specific geometric formulae appropriate to particle physics experimental needs. When optioneering these alignments, the spectrum of possibilities of their various threedimensionally rotated forms and positions needs to be accounted for. These requirements have significant engineering implications for the alignment option as well e.g. a maximum vertical deviation in the alignment of about 80m would be achieved between the planar and Earth s curvature solutions. Similarly, even a 1% gradient would have a depth impact on the tunnel of over 300m across a 100km collider ring. Fulfilling all of these requirements and having the ability to manipulate the different options in a robust way has been made possible through the creation of this early-stage BIM tool. TOT both manages the data requirements and models the effects of these requirements as programmed functional operations within the BIM tool.

5 16 TheStructuralEngineer Feature Figure 4 3D PDF showing various early-stage iterations of FCC Geological and topographic constraints The geology and topography across the alignment investigation area are key first-order influences in determining the tunnel alignment corridor. These data are represented through 3D digital mapping information. Digital elevation models (DEMs) produced from space shuttle or airborne flights exist for much of Earth s surface. Highresolution data are increasingly available through government/institution-funded initiatives. These can also be commissioned through collection of specified data over certain areas should the most up-to-date data or particular granularity of data be needed. For TOT, satellite data from the Copernicus European Earth Observation Programme have been used to create the DEM; however, the tool has the flexibility to integrate any standard DEM data set with any granularity of detail. The DEM provides the 3D terrain data across the investigation area. TOT utilises this data set by allowing for the import and 3D manipulation of a tunnel alignment through this, and in doing so creates automatic cross-sections through the terrain for any given alignment. This allows the user to efficiently assess and visualise important tunnelling parameters, such as overburden depths and potential tunnelling conditions. This optioneering is particularly relevant in this project, where elevation variations across the investigation area are over 700m between the plains of the Molasse basin and the mountain belts of the Jura and Pre-Alps. The results can be visualised through summary statistic graphs and numerical data outputs within TOT. Should subsequent post-processing of this data be necessary, there is functionality for export of the data outside of TOT for further usage. The subsurface 3D model has been created from digital mapping of the subsurface rockhead levels of the key geological layers. The project team worked with Géotechnique Appliquée Dériaz S.A. (GADZ) and the French Geological Survey (BRGM) to create these digital layers, through analysis and processing of historic borehole data and regional geophysics seismic data. Other 3D data sets include water bodies, such as Lake Geneva, where 3D bathymetric data of the lake bottom, from Le Système d Information du Territoire à Genève (SITG), has been included in the model. In the same way that TOT utilises and models the surface DEM in the tool, the 3D geological rockhead layers and bathymetry are imported and processed within the model, allowing the user to optimise an alignment based on particular geological conditions. The tool relies on these information sets to provide the data-rich environment for effective manipulation of the tunnel optimisation tools. Nevertheless, it is worth highlighting that the same data sets would need to be obtained, regardless of their use in TOT, during this stage of a conventional feasibility design study. The difference is the way in which these data are used. TOT extracts best use of the available data, integrating the multivariate data sets into a single system, and in doing so allowing for their interactions and implications to be easily observed and assessed. With the move to an ever-more digital environment in all sectors, digital data sets such as subsurface geology and geohazards are increasingly being produced in a georeferenced and attributerich format. There is a drive for this from the main data producers, such as the national geological survey bodies, but also conventional commissions. This provides the opportunity for BIM systems to utilise these data sets in new and useful ways. As the project develops, further layers of data and functionality are necessary. Integration of these through TOT allows for these updates to be made in a consistent manner, as the maturity of data and the granularity of data increases according to the project stages. Surface constraints Collision of particles along the FCC will occur at interaction regions within experimental caverns fed by the tunnel systems. At these locations, shafts to the surface will be needed during construction and operation. Particular focus is necessary in optioneering these site locations in order to minimise impact on settlements and protected areas, to avoid interference with existing man-made features such as underground pipelines and geothermal wells, and to maximise opportunities for connections to access roads etc., which are of benefit during construction and operation. In a BIM model for a building, the clash-detection benefits of BIM relate to detection of where asset components overlap and conflict, such as detection of where a water pipe may be clashing with a heating, ventilation and air conditioning (HVAC) system. However, the clashes of interest at the feasibility stage of a tunnel

6 17 alignment study include more wide-scale interactions, such as when a surface feature may clash with an access shaft. TOT allows for identification of these wide-scale factors through integration of high-resolution satellite imagery. User functionality allows for dynamic update of the model cross-sections and data statistics output while optioneering shaft positioning around potential clashes. Future steps TOT s accessible interface and ease of use have developed into one of its key benefits. Its simplicity belies the fact that the underlying data are multi-spatial and information-heavy, processed through an array of complex analytical procedures. TOT simplifies these components, and presents robust and repeatable results within a user-friendly platform. This creates a shared common-data environment through which effective decisions can be made clearly and accountably by any team member, even for those without any technical BIM capability. As the project progresses and the level of development increases, the open nature of TOT will provide a consistent platform with the flexibility to adapt in line with changing requirements and increasing project demands. Future steps for the development of the tool could include increased automation and intelligence to the decisionmaking ability; mapping of data uncertainty; and creation of the 3D BIM output. Increasing automation and intelligence in TOT would aid in the risk-based identification of potential impacts and their consequences. Genetic algorithms employ artificial intelligence to create optimised solutions to given scenarios. These can be developed on TOT to selfoptimise a solution based on a particular set of constraints and rules, or to simulate outcomes based on different distributions of inputs. As much as TOT creates a central source of truth, understanding and visualising where the limitations to the data lie is important. This will allow for a better informed decision on the confidence of a particular alignment position, as well as identifying where further knowledge is needed to ensure a level of certainty in the data over a particular area or decision. Heat maps of data confidence can be programmed to identify these areas of uncertainty and data improvements. Visual representation of data is a powerful communication mechanism, and needs to be appropriate to the decisions which it is aiming to inform. TOT represents the underlying 3D data in 2D forms and this presentation of data has been a key non-tangible benefit. The visual aspect of the tool has helped with communication of decisions and has provided a platform for understanding of associated issues. Being able to easily visualise the options has improved understanding of the issues involved and has enabled users from all disciplines and levels to interact and develop solutions collaboratively. 3D representation of the model through TOT may become appropriate as the "Being able to easily visualise the options has improved understanding of the issues involved" project requirements change. The opensource technology stack framework and data-centric approach lay the foundations for creation of a 3D representation as the project stages advance. A truly immersive 3D model would need to incorporate information-rich data and functionality beta development of this for the FCC is illustrated in Figure 3. Currently, processes exist to convert outputs into a 3D PDF to aid visualisation (Figure 4). Development and utilisation of 3D modelling and visualisation of geological data are similarly progressive in the mining and petroleum engineering disciplines. These industries have exemplified their application to help identify future production seams and drilling potential. As with other crossover technologies between the mining/petroleum and civil/structural industries, there are many parallels and potential learning opportunities. An example can be seen in the complementary advances in drilling technologies and tunnelling/shaft-sinking techniques. The application of BIM and the push to a big data digital economy present another opportunity. Initiatives such as the British Geological Survey s (BGS) National Geological Model (NGM) and the BRGM s plan for the French Geological Reference Platform (RGF) are initiatives driven by the independent national bodies to coordinate and deliver digital geological information. Pairing this with industry strategies, such as the Digital Built Britain strategy advocated through the UK government s BIM Task Group, presents opportunities for innovation and savings, which will improve cost and efficiencies through the design process. Conclusions The application of TOT to the FCC project at CERN has created a platform for a more effective understanding of the tunnelling issues and their impacts at one of the most influential stages. As digital data, data modelling and analytics become increasingly accessible and developed, BIM platforms such as TOT will help create more innovative and beneficial approaches to manage and handle these early project data and their inherent uncertainty. Much of the BIM discussion has been around its crisp definition and component software and technologies. However, regardless of this, what BIM really enables is a data-centric, collaborative approach, which also improves workflow and efficiency. Through this wider appreciation and an understanding of the tools and mechanisms that can be used to achieve this, TOT has demonstrated how BIM can be successfully applied at an early project stage to create increased value from the existing underlying data, the essence of BIM. Following the use of TOT for the conceptual stage of CERN s FCC project, the data and functionality will be used and improved upon in ongoing phases. A baseline of options has been determined at this stage and the data used are directly feeding into risk and cost models. As the project develops, a compatible level of data maturity will be required

7 18 TheStructuralEngineer Feature to match this. The benefit of TOT is that these areas for increasing data definition can be more easily identified as the model options are distilled and the areas for data improvement and requirement tolerances become selfevident. The current data set-up and organisation within the TOT common data environment also lay the foundations onto which increasing levels of development and detail can be added in the long term through the open-source framework of the system. This central source of data for the Molasse basin also affords the opportunity for data reuse and knowledge sharing on other projects at CERN and in the region. Reuse of the tool itself is also possible for other linear infrastructure projects. This is already planned for a separate project for the International Linear Collider (ILC), where a preferred site for the 30km long particle accelerator tunnel has been identified in Kitakami, Japan. Use of TOT for this project will help identify an optimum location to site this tunnel, and help bring similar efficiencies and long-term benefits to this project. The creation of BIM platforms such as TOT will only help to create more innovative approaches to the use of data. By embracing the opportunities that BIM and digital engineering have to offer, engineers will increasingly be enabled to create smarter solutions to existing and future engineering challenges from the earliest concept, to the more familiar design and delivery stages. References E 1 Department for Business, Information & Skills (2012) BIS/12/1327: Industrial strategy: Government and Industry in Partnership Building Information Modelling [Online] Available at: (Accessed: April 2015) E 2 Department for Business, Information & Skills (2015) BIS/15/155: Digital Built Britain: Level 3 Building Information Modelling Strategic Plan [Online] Available at: government/publications/uk-construction-industry-digitaltechnology (Accessed: April 2015) E 3 CERN (2014) Future Circular Collider Study [Online] Available at: (Accessed: April 2015) E 4 Construction Users Roundtable (CURT) (2004) Collaboration, Integrated Information, and the Project Lifecycle in Building Design, Construction and Operation [Online] Available at: CurtCollaboration.pdf (Accessed: April 2015) The 2015 international Conference is being held in the centre of a thriving structural engineering hub; Singapore. We encourage all professionals within the field to attend the conference, and: Develop and enhance knowledge on range of topics Hear from a selection of world class speakers Network with international professionals Experience the rich culture of Singapore TICKET SALES END 17 JULY Book your tickets now to avoid disappointment! TICKET PRICES: Institution Member ticket: S$930 Non-Member ticket: S$1040 Conference Dinner only: S$160 Grand Hyatt Singapore, 10 Scotts Road, Singapore #Singapore15 With thanks to our sponsors: