GEOTEST is overseeing major refurbishment works along the Zentralbahn line between Interlaken and Meiringen
Haslital
46° 45′ 03″ N 8° 06′ 05″ E
2017 - 2026
The closure is being used to renovate sections of track that are over 100 years old, refurbish stations and make lasting improvements to flood protection.
GEOTEST AG was involved in three major projects – the complete refurbishment of Junzlen, the refurbishment of Brienzwiler station and the complete refurbishment of the Aare delta – throughout all relevant project and implementation phases. The services covered engineering geological, geotechnical and hydrogeological issues, as well as matters relating to waste management and contaminated sites legislation – from planning through to construction.
GEOTEST is supporting Zentralbahn’s railway projects in the Haslital valley, drawing on its expertise in matters relating to waste management and contaminated sites legislation, amongst other things.
Due to the Aare river’s close proximity to the railway line, there is a risk of flooding affecting train services.
Complete refurbishment of Junzlen
Lots 1 and 3 have already been completed. Now it was time for the complete refurbishment of Lot 2, the most logistically challenging section. The track was completely renewed over a distance of around 2,600 metres to make the railway line permanently flood-proof – a key challenge, as the existing railway embankment is regularly flooded by heavy rain and high water levels in the Hasliaare.
Various methods are used to protect the railway line running alongside the River Aare from flooding.
The concrete angle support elements are particularly important for flood protection.
In addition to the standard engineering and geological work, a significant amount of structural engineering work was also carried out: the railway embankment was raised, a continuous drainage system was installed, and new flood defences were erected using prefabricated concrete angle support elements. In addition, over 30 new catenary foundations were constructed, along with around 37 crossings for wildlife and small animals, to ensure the ecological connectivity of the route.
GEOTEST’s services for the Junzlen comprehensive refurbishment project:
Comprehensive project and construction supervision in SIA phases 31–52
Engineering geology, geotechnics and hydrogeology
Geological, geotechnical and waste management investigations
Support in planning regarding flood protection issues
Preparation of geological longitudinal profiles
Assessment of subgrade material quality and bearing capacity
Advice to the site management team (öBL)
Advice on waste management and contaminated site legislation, including a disposal concept
Instructions for disposal in accordance with VVEA and track excavation guidelines during construction
Thanks to close cooperation between the site management (Bächtold & Moor), the construction company STRABAG, the UBB (Sigmaplan) and GEOTEST, the complex site situation was successfully managed through precise logistics and effective coordination.
Renovation of Brienzwiler railway station
Brienzwiler station is being completely refurbished as part of a PGV project. Geological challenges such as poor ground conditions, the influence of groundwater and a former army fuel transfer station required in-depth analysis and sustainable solutions.
One challenge at Brienzwiler station is the poor bearing capacity of the subsoil.
Due to its composition, its bearing capacity must be improved prior to construction.
Using a radioisotope probe...
...the moisture content and density of the subsoil are measured at various points.
GEOTEST’s contributions to the Brienzwiler railway station refurbishment project:
Project management and reporting on geology, hydrogeology and waste management (SIA 31–52, PGV)
Geological, geotechnical and waste management investigations
Foundation and ground improvement concepts
Concepts for excavation enclosure and dewatering
Preparation of geological longitudinal and cross-sections
Groundwater monitoring using data loggers
Advice on waste management legislation, including disposal concepts
Guidance on material sorting and monitoring of material flows
Advice to the site management team (öBL)
Complete refurbishment of the Aare Delta
Along the Aare Delta, the line was not only renewed but also reinforced against flooding. The third and final phase was completed in 2025. The entire project benefited from engineering-geological analyses and hydrogeological planning to ensure track stability, subgrade improvement and the quality of the materials used.
The old railway ballast and its sub-base are being professionally removed and disposed of under the supervision of GEOTEST.
This creates space for the new materials to be laid on the track.
GEOTEST’s contributions to the Aare Delta Comprehensive Redevelopment Project:
Project management and reports on geology, hydrogeology and waste disposal (SIA 31–52, PGV)
Geological and geotechnical investigations
Preparation of geological longitudinal and cross-sections
Planning and consultancy on ground improvement
Bearing capacity analyses of the subgrade
Waste and disposal concepts
VVEA-compliant utilisation of track excavation
Instructions for on-site sorting and material monitoring
Consultancy for the local site management (öBL)
Conclusion: Comprehensive support for complex rail projects
The three projects along the Zentralbahn line serve as prime examples of how important it is to have continuous geological, geotechnical and environmental legal support – particularly in the case of old railway lines, flood risks and complex ground conditions. GEOTEST helped to analyse these challenges professionally and integrate them into the construction processes – from the early planning stages right through to the actual execution. Technical expertise and a constructive, collaborative approach were always at the heart of the work.
Thanks to the excellent cooperation with the various parties involved, GEOTEST was able to complete the project on schedule and efficiently.
Auftraggeber
