Tackling challenging layouts
Author: Tamara Stakic
The construction industry is embracing digital robotic total stations for the layout of building elements and internal fit out due to proven financial and time benefits– replacing the laborious tape measure and stringline approach.
Traditionally, the layout of building services on site involved working based on the provided paper drawings. These drawings were used in combination with tape measures, levels and grids to identify location points for elements, such as penetrations, pipework and cable trays. This is all changing now.
Digitising building construction layout
Based in Melbourne, Australia, V Constructions specialises in both high residential and commercial construction. Many of their recent projects feature complex designs with curved walls and buildings with prefabricated materials and non-orthogonal spaces. Seeking to improve efficiency, ensure accuracy and provide quality control, V Constructions purchased the Leica iCON robotic total station after being appointed as main contractors for the Holme apartments development; a 14-floor mixed-use development comprising of continuously curved slabs, glazed curtain walls and balconies.
V Constructions, a long-term customer of C.R. Kennedy, Leica Geosystems distributor in Australia, understood the need to adopt a digital workflow to work with complex shapes and move forward with the project faster than traditional methods. The company had little time to switch to a digital workflow after finding out it won the project.
“We needed a solution that was easy to adopt, user-friendly and required minimal onboarding time,” said Douglas Thirkell, senior surveyor at V Constructions. Switching to a digital workflow and adopting the instrument was easy thanks to C.R. Kennedy who provided technical support on site as the team implemented the iCON robotic total station from day one of the project. “The product was easy to pick up and use straight away by the team,” said Thirkell.
Designed by award-winning John Wardle Architects (JWA), the sculptured design includes 154 apartments, commercial and retail spaces above ground, and a 160-car park within three basement levels. The building façade is a standout feature of the development with the original 1920s Art Deco façade being retained on the lower floor frontages and alongside a new suspended brickwork façade.
With the help of the iCON robotic total station, V Constructions is providing the accurate positioning of building structure, steel reinforcement, concrete layout and the finished levels. The complex nature of the building design would have made it near impossible for the V Constructions team to layout using traditional methods.
Making the switch to a digital workflow
V Constructions traditionally used Leica Geosystems total stations (Leica TCR407 and Leica Builder) for previous building construction projects. The complexity of the Holme apartments project made it necessary for the team to invest in a layout instrument in order to be more efficient on the site.
Due to the complex nature of the building, each apartment is unique – there are 42 different sizes of wet areas and not many repetitions of the apartments on each floor. This sophisticated structure involved a greater amount of work for V Constructions surveyors Thirkell and Brian McLoughlin as they had to layout each individual piece. The iCON robotic total station allowed the team to layout metal sections and fabricated concrete curves with simplicity and efficiency.
“What was key for us when evaluating the technology investment is that the instrument had to be robotic and a one-person operation,” said Thirkell.
Tackling complex layout challenges with efficiently and accuracy
The team at V Constructions set up multiple survey control points on site for instrument orientation purposes at any location around the curved structure. This technique meant they did not need to use grids for orientation when completing layout tasks.
By adopting a digital workflow, V Constructions was able to ensure the setup of the instrument was completed quickly and accurately and all plan data was immediately available on the controller. This ensured quick and accurate layout processes were followed and there was no need to worry about some of the variables and the inaccuracies that come with using traditional methods involving stringlines, tape measures and spirt levels.
Every small mistake can lead to potentially serious consequences. Being a few degrees out on an angle can cause pre-fabricated systems not to fit when the time comes to install them. Similarly, incorrect layout can result in clashes with other building elements or services, thereby disrupting the construction schedule, generating unnecessary works and wasting materials, time and money.
On the Holme site, the windows of the building contained curves and the glaziers relied on the accuracy of the placement of the hobs to place windows – the hobs are premade and fixed to the form work. There was no room for error for the V Constructions team and only a digital method could provide the team the confidence in accuracy needed – there was not a tape measure or stringline to be seen on the site.
“The traditional approach [to layout] is laborious and time-consuming, and any delays can affect the work of other teams. Adopting digitisation and the Leica iCON robotic total station is really the way of future for us,” said Thirkell.
Speeding up as-built plans
One of the key stages of the project that had tremendous efficiency gains was the as-built plans.
Thirkell and McLoughlin were required to complete an as-built survey for every slab. Traditionally, they would set up a laser level and take a reading, manually creating a plan of the completed slab in the office. With the iCON robotic total station, the team can record the data and within an hour upload it into CAD where it would be cleaned up and used to prepare the as-built plan.
Quantifying the productivity improvements, adopting an iCON robotic total station has saved V Constructions one person per day. These are the considerable time savings that may ultimately reduce the number of operatives required on the project and reduce labour costs.
Expanding productivity gains
V Constructions realised the productivity gained by implementing a digital workflow during the Holme project and invested in its second iCON robotic total station for a new project – a chancellery building at Monash University. Located at the Clayton campus, the 10,000-square-metre building will comprise of a single basement level for car parking, ground level public spaces, two levels of office space and a third level to house the University executive. The building includes a feature steel sunshade screen that wraps all elevations of the thermally-enhanced façade.