171 make it Australia’s fifth-largest city), pushing the region’s total population to nearly 5 million. Most of these new arrivals will live outside of Brisbane, but within commuting distance. Many of the new jobs, however, will be in the Brisbane central business district (CBD), on the north bank of the Brisbane River. Current rail infrastructure is insufficient to handle the necessary increase in CBD-bound train traffic. Cross River Rail will add 6 kilometers of twin tunnels under the river and four new underground stations. A Bigger, Better Model Soon after the project was announced, the Cross River Rail Delivery Authority, the overseeing agency created by the Queensland government, sought advice from colleagues on the other side of the world. The Crossrail project in London, launched in 2009, has similar aims, creating new tunnels and 10 new underground stations throughout Central London. Crossrail involves construction beneath a metro area even denser than Brisbane’s, with extremely narrow margins to avoid damaging existing underground infrastructure. “They’re like our big brother that we idolize,” said Russell Vine, Cross River’s chief innovation officer. By the time Cross River’s plans were beginning, Crossrail had been under construction for almost seven years. The Cross River team contacted their British counterparts and asked what, if anything, they would do differently if they could start over. “They basically said, ‘We would have built a bigger, better 3D digital model sooner,’” Vine said. The big brother then offered three steps for how to build the perfect GIS-driven digital twin: 1. Create a common data environment. 2. Stipulate that all contractors use the same standards in their 3D architectural models so that they can all combine into a single model for the project. 3. Make the model immersive. An Expansive Mission For starters, Crossrail recommended that Cross River create a common data environment for all work. Any project-related dataset, no matter what the format—GIS, BIM, volumetric, photogrammetry (a three-dimensional coordinate measuring technique that uses photographs), everything—should be in a central repository. This was useful advice. GIS technology has become adept at integrating BIM models and other project-related data formats into a GIS environment. BIM models are 3D architectural models. They describe and depict the actual things being built or dug, whereas GIS adds contextual awareness. Rather than just consider the BIM models as inert objects floating in space, people involved in a project can visualize what’s around them. In GIS, they can see how each structure fits into the infrastructure above ground (such as paths, roads, and light poles), underground (the pipes and lines that connect utility services), and to the natural world Infrastructure A BIM model of Wgabba Station shows the level of detail required to guide construction.
RkJQdWJsaXNoZXIy MjA2NTE0Mw==