Constructing Sweden’s Tallest Tower Using ComNav Technology

Construction of the Karlatornet, soon to be Sweden’s tallest building, is well underway in the city of Gothenburg. Standing at 74 stories and 246 meters tall, this skyscraper will transform the city’s skyline. To ensure the stability of such a tall structure in the face of strong winds, sun exposure, seismic activity, settling, and shrinkage, engineers are employing high precision construction methods.

The core wall control survey (CWCS) method is being utilized to maintain the building’s vertical alignment. This method, which relies on active GNSS control points and SinoGNSS T300S high accuracy GNSS receivers, was first used during the construction of the Burj Khalifa in Dubai and has since been implemented in various high-rise projects globally. Swedish surveying company Teodoliten has chosen to implement this method for the Karlatornet project.

Core walls, critical structural elements in high-rise buildings, require a meticulous layer-by-layer construction process. The CWCS method allows for precise alignment of these core walls with the building’s vertical axis using a combination of GNSS receivers, total stations, inclinometers, and other tools.

During construction, it is crucial to continuously monitor the positions of various elements at the building’s summit to ensure their vertical alignment. Four GNSS receivers, known as active GNSS control points, are placed at the top of the building with 360° prisms attached. This setup eliminates the need for ground control points and vertical laser plummets. The Karlatornet project utilizes SinoGNSS multi-constellation T300 GNSS receivers for these active control points.

To account for the building’s movement as loads are applied during construction, high-precision dual-axis inclinometers are placed along the core walls. A least squares adjustment process considers the floor height of these inclinometers to correct for any movement of the survey platform.

Post-construction, the SinoGNSS T300 receivers will continue to be used to monitor and document building deformations. This ongoing monitoring ensures the structural integrity of the Karlatornet as it takes its place as a defining feature of Gothenburg’s cityscape.