Digital construction

Steel and digital construction


Digital processes have impacted significantly and positively on the complete supply chain for delivery of a finished steelwork structure, resulting in improved speed, safety, constructability and quality.

Outlined below is a range of solutions either currently implemented or being rolled out. 

Building Information Modelling (BIM) 

“Building information modelling is a process involving the generation and management of digital representations of physical and functional characteristics of places. Building information models are files which can be extracted, exchanged or networked to support decision-making regarding a building or other built asset.” (source: Wikipedia). 

Digital interoperability through the complete supply chain is facilitated by implementation of BIM and the Industry Foundation Classes (IFC) data model intended to describe building and construction industry data. 

While BIM and IFC can flexibly model all construction products and facility types, the object-oriented nature of the 3D spatial models utilised are a natural fit for structural steelwork, paralleling the inherent level of prefabrication utilised across the construction of steel structures. 

BIM adoption in Australia is becoming well entrenched, supported by initiatives such as the: 

Computer-aided Design / Computer-aided Manufacture (CAD/CAM) 

Advanced 3D detailing software supports steelwork construction modellers (detailers) with creating the rich 3D models that exactly and precisely describe the structural steelwork required to be fabricated for the project. The detailing software can accept as input the IFC files generated by the BIM software and create conventional detail drawings of each steelwork part and assembly. It can also create electronic files that are used to drive Computer Numerically Controlled (CNC) fabrication machinery that can variously and automatically cut, hole, cope and weld steel members to create the final prefabricated components and assemblies. 

Automated welding of plate web girder.

3D laser scanning 

A 3D scanner analyses 3D objects and returns information about the object, usually to enable the geometric shape to be calculated, but also possibly its appearance (e.g. colour). 3D laser scanners are typically used to scan larger area data, such as buildings and their environment, utilising typically time-of-flight laser range finding.

The distance to the closest object is measured one point at a time over the entire measurement field. The result is a so-called ‘point cloud’ of data points. Modelling software can be used to reconstruct the primary 3D shapes from the point cloud, or the point cloud superimposed on 3D models for the purposes of clash detection, assessing site placement of new structures or the like. 

New construction superimposed on existing 3D scanned structure. Courtesy Watkins Steel.

Augmented Reality (AR) and Virtual Reality (VR) 

Augmented reality (AR) and Virtual Reality (VR) are at the early stages of adoption at various points in the supply chain for steel structures. The potential, in particular, to interpret existing site conditions and constraints, in combination with 3D laser scanning, can facilitate better and safer outcomes for retrofitting in existing facilities. 

AR and VR have been trialled and/or implemented for a number of use cases, such as the following: 

  • Augmented reality has been used to guide fabricators during manual fabrication, utilising headsets to superimpose images of the intended finished article onto the work piece. See, for example, this Spiral stairs Hololens video illustrating the superposition of the 3D spiral stair model on the stair unit during fabrication.

Operator using VR headset during fabrication. Courtesy Watkins Steel.
 

  • Clash detection of 3D models against 3D laser-scanned site models 

3D model of arbour structure superimposed on 3D laser scanned site, with clash of arbour structure against existing building indicated. Courtesy Watkins Steel. 

Arbour structure during construction. Courtesy Watkins Steel.

Resources


The National BIM initiative

The Australasian BIM Advisory Board

The Australasian Procurement and Construction Council

The Australian Construction Industry Forum

AISD – Australian Institute of Steel Detailers (Watch this site for rebranding coming later this year)