Building paradise with precision

Author: Renata Barradas Gutiérrez

Guests entering the THERMEN & BADWELT SINSHEIM, a thermal bath paradise in southern Germany, can relax among more than 400 tropical palms in a tropical landscape that conveys a holiday atmosphere. The 64,000 square feet thermal bad complex offers unique sauna attractions, such as the largest sauna in the world, a 25 meter swimming pool, and a bathing palm paradise covered by a mobile glass roof.

With the help of the surveying and geo-information centre office Schwing & Dr. Neureither, the complex emerged in a record time of 12 months and opened its doors in 2012. This 45 million euro bathing complex has earned four excellence awards and is the largest thermal bath in Southern Germany.

The tasks performed by the surveying office Schwing & Dr. Neureither included:

• Setting of axis for concrete and steel construction
• Continuous control measurements during the construction phase
• Monitor measurements after the completion of the project.

To achieve this, the surveying office needed an instrument that could combine the latest technologies in the fields of total station measurements, digital imagery, 3D laser scanning and GNSS positioning.

Leica’s MultiStation: an all-in-one solution for all tasks

The THERMEN & BADWELT SINSHEIM project encompassed all planning and construction-related surveying services. In order to be able to offer innovative and economical solutions with the highest precision, the Schwing & Dr. Neureither office opted to use the Leica Nova MS50 MultiStation for all the tasks in this project. These tasks included:

• Creation of a fixed point field
• 3D laser scanning
• Stake out of construction elements
• Control measurements
• Monitoring measurements
• 3D laser scanning documentation

“I was delighted that the management team decided to purchase the Leica Nova MS50. The precision and speed of the instrument are simply outstanding,” said Hardy Schwalb, department head of Schwing & Dr. Neureither.

A balance of accuracy, range and speed

High accuracy measurements were essential to ensure that the complex developed with low energy consumption, resource conservation and sustainability standards. To achieve this goal, large movable glass roofs had to be built to guarantee maximum heat generation from solar energy and allow a total shutdown of all heating and ventilation systems in sunny weather conditions.

“We needed a precision of less than 3 millimetres to build the movable steel roof. This accuracy was easily achieved with the MS50,” said Schwalb.

To define the concrete and steel axis, the total station functionality integrated in the MultiStation automated the measurement procedures. A combination of metal studs and reflex marks was used for the marking of the points. The internal accuracy of the fixed-point field obtained was, in the position as well as in the height, less than 1 mm. “It is noticeable that the distance measurement range of the MS50 provides very good and, above all, reliable results,” said Schwalb.

“It was very helpful to save the planning data in the DXF format for the performed stakeout work. In this way, it was easy to define the axis in the graphic. Thus, analogous plans were for the most part relinquished. This led to a reduction on the work load,” said Schwalb.

After the first construction phase of the THERMEN & BADWELT SINSHEIM was completed, a 3D laser scanning documentation was performed. To visualise the topographic survey data, complex structures had to be recorded in parts; these areas were easily detected and documented with the 3D point cloud function and with the internal wide angle camera. These functions were made easier for the Schwing & Dr. Neureither team to bring technical data together and work the details in the office.

“The challenge was that the heated pools released water vapour, especially in the outdoor area. It was to be expected that under these conditions the results of the point cloud measurements had to be questioned. However, despite the extremely high humidity, the MS50 followed the IP65 specification and delivered flawless and reliable results over the entire duration of the project,” said Schwalb.

In the closing words of the department head, “the Leica Nova MS50 offers a lot of functionalities and therefore also great advantages. Thanks to the high achievable accuracy, various problems were reliably solved. The measuring time was fast due to the high speed of the 3D laser scanner; this allowed a more economical processing of the projects that ultimately benefited the client.”