**5.2 Use-case 2: infrastructure (operation and maintenance phase)**

The project used for the second use case is an already completed infrastructure project - a new bridge (**Figure 6**) over the Savinja River in Marija Gradec, near Laško. The bridge is 123 m long and up to 12 m high and designed as an anchored containment structure. The bridge construction started in mid-July 2019 and was opened for traffic in February 2021.

The use case clearly addresses the use of AR in the operation and maintenance phase (7D, see also **Figure 2**) of the life cycle [26, 27]. BIM model (3D geometry only) was available and correctly georeferenced via the mobile platform used [6]. This made it possible to obtain real-time architectural visual interaction and communication. Another important point for the choice of this site as a case study is precisely the counterpoint that apart from the 3D model BIM in IFC format as basic information, no other accessible database is available, which imposes major limitations for its use and visualization in augmented reality. Overall, it is possible to check the 3D model BIM and compare the same coordinates on Google Maps as shown in **Figure 7**.

Key takeaways: (1) it is essential for the of AR system, that BIM model includes additional information to basic 3D geometry, (2) positioning/scaling of BIM model in AR system possible due to available reference points, (3) difficult to use tablets/ smart phones in bright sunlight.

**Figure 4.** *The stand point 1 (a) and the stand point 2 (b).*

*Using Augmented Reality in Different BIM Workflows DOI: http://dx.doi.org/10.5772/intechopen.99336*

#### **Figure 5.**

*Visualizing (a) a railway track and (b) a portal to a tunnel.*

**Figure 6.** *The Marija Gradec bridge.*

**Figure 7.** *The geoposition of the bridge in Google maps (left) and BIM model (right).*
