Geology und geothermal energy with complex underground conditions

In the centre of Stansstad on Lake Lucerne, plans for the new residential development Schürmatt comprise eight apartment buildings with a total of 84 rental and owner-occupied apartments and a shared parking garage. GEOTEST Horw carried out construction ground investigations in the design stage and later in the construction phase. In the corresponding reports, the geological and hydrogeological conditions, an optimised construction ground model, the geotechnical parameters and the groundwater conditions were presented. Based on this information, the concepts for the excavation pit closure, drainage and foundation could be devised. Furthermore, GEOTEST prepared a soil protection concept for the Nidwalden Office for the Environment.

The aim of the building owner is to heat and cool the new buildings sustainably using groundwater, which poses a particular hydrogeological challenge because of the numerous existing users in the area.
 

With thermal groundwater modelling, GEOTEST has examined the feasibility of this endeavour and is now responsible for the utilisation concept and the corresponding construction of filter wells. In total, the groundwater is to be pumped into two filter wells and returned to three filter wells in the outflow. The locations of the filter wells were determined with the help of groundwater modelling.
 

During the construction phase GEOTEST supervised the civil engineering work and was responsible for groundwater monitoring. One of the greatest challenges was the lowering of the groundwater level as a result of the complex and widely varying subsoil conditions throughout the site.