Niall Brady (Digital Engineering Lead) and Jarred Dickson (Senior Highway Engineer) of Arup Sydney addressed the delegates of our 2018 12d Technical Forum recently about an exciting project they’ve been working on – Stage 1 of the Parramatta Light Rail.
The Client for the project is Transport for NSW. Stage 1 of the Parramatta Light Rail will connect Westmead to Carlingford via the Sydney CBD & Camellia. It will consist of a two-way track spanning roughly 12km, with both on-line (through urban streets) and off-line sections. The track is due to open in 2023.
Parramatta is in the west of Sydney. The areas that were discussed in this presentation are Enabling Works Packages in Sections 1 and 2 – along Church Street and O’Connell Street (moving traffic off Church street onto O’Connell Street to allow for the construction of the light rail), and Section 3 (along George Street – moving traffic off Macquarie Street onto George Street and changing George Street from one lane to two in each direction). This will also involve a section along Hawkesbury Road – adjacent to the upgrade of Westmead Hospital.
The scheme is currently in the Tender Review Stage. Stage 2 has been announced and is in its early design stages.
Arup needed to be able to deliver all three Enabling Works Packages in 16 weeks – a very quick turnaround – to submit to a contractor to be constructed before the main works commenced. It was necessary for a high level of Digital Engineering to be applied. This led Arup to develop a 3D Federated Model, applying Work Breakdown Structure and Naming to enable 4D BIM Cost, 5D BIM Cost, and 6D BIM Asset Management. They also used a model for Design Coordination and Stakeholder Engagement.
So what is Digital Engineering? According to Arup, it is a “collaborative way of working using digital processes to enable more productive methods of planning, designing, constructing, operating, and maintaining assets. This is achieved by creating a Common Data Environment (CDE) that aligns digital information systems – including CAD, controls (time, cost, risk, etc.), asset data, and other data systems.”
Digital Engineering in 12d Model
The design tools the Arup road design team used to reduce the amount of rework, documentation, etc., and ideally get design right first go, included:
The team tried to limit the number of manual inputs into Snippets that could result in errors, so the Snippets had the code embedded or hard-coded in, or referenced project details, attributes, etc. to create consistency across the project. The theory was that if the design models are consistent, the output models should then be consistent.
In addition to design elements, they drew upon other Snippets – e.g. vertical clearance envelopes, modelling clear zones within 12d (this meant they could design barriers on the fly without needing a review process afterwards). Other disciplines were also using these outputs – e.g. clear zones to landscaping teams so they knew what they could plant where.
Snippets worked in the background to embed attributes into trimeshes, so when they sent IFC models out to other packages, they could interpret the designs straightaway without asking questions – this sped up coordination between disciplines.
Standardised/transferable chains. One source meant one chain could be run multiple times, taking advantage of parameter files. This meant they could make tweaks to outputs easily and then get consistent outputs across disciplines and packages.
The team also filtered 12d data to geographical regions and attribute data, and used this to connect models across all systems to apply cost and time for construction.
They took that a bit further and, rather than using chains with parameters, they wrote macros (e.g. Automating Road Furniture – Line Marking, Kerbs, Traffic Signs, Scheduling; Design Verification – Aquaplaning; Design Verification – Swept Paths, Sight Lines – for e.g. mapping 3d survey model to actual 3d objects, HGL to Trimesh) – this mean they didn’t need to upskill others on parameter files; the macro provided a user-friendly interface. This saved a lot of time in documentation, training, etc.
All this was done “on the fly” (including conformance checks) so there was less checking at the end.
Utilities are critical, especially in an inner-city environment – they can be high-risk on projects such as this. The Arup team worked with transport and other consultants to set up a better process for coordinating utilities.
The UUS Schema, Utility Specification, Surveyed Information, and DBYD (GIS Data) were read into a 12da file (single source of information), which then populated the Navisworks 3d Model, GIS Portal, and 12d Model, which in turn created the Utility Design, Rail Design, Drainage Design, and Road Design.
The Utility Schema was based on the AS 5488 Classification of Subsurface Utility Information (SUI). Additional attributes were added and standardised to simplify GIS setup, 12d Mapping (long sections and cross sections), and Federated Models properties. Every utility had approximately 70 attributes for type, clash, risk, and treatment.
Utility Coordination – 12d Workflow:
- Digitise the Dial Before You Dig data in 12d Model
- Identify additional utility survey required
- Import 12da file from Surveyor
- Apply unique ID (GOID) using a macro
- Apply attributes using a string filter
- Apply remaining attributes from Register
- Apply attributes from mapfile
- Apply pipe diameter from ‘pipe size’ attribute
All this was automated in a Standardised Chain
- The model was then exported to IFC for GIS and Federated Models
The team was pleased to note that when you select a string in 12d Model and view its properties, you can take that forward and see that exact information in the GIS Portal and in Navisworks; this powerful functionality was a great help to them on this project. Their deliverable was a full set of drawings – longitudinal and cross sections, so there was much to be done.
The GIS Web Platform doesn’t require software – users can just click on the utility portal. They were also able to provide access to contractors.
Federated Model – IFC Files
Along Hawkesbury Road, a number of different consultancies, as well as disciplines, were involved. These were brought together in 12d Model. All files were exported as IFC.
Arup delivered this entire detailed design in just 16 weeks. They delivered the 3D BIM model with attributes for 4D, 5D, and 6D, as required. They also delivered a full set of drawings for all disciplines. This was all done with a small full-time team – 3 engineers, 1 designer, 1 CAD person. By using a model in stakeholder engagement and speaking frequently to client RMS they reached ‘Agreement’ on departures (trees in clear zone/sightlines).
They could not have achieved these results without 12d and adopting Digital Engineering processes.