Underground & Tunneling

Our core competence builds on the great Swiss tunnelling heritage. Risk management in tunneling starts with the systematic analysis of the geological and hydrogeological fundamentals, which leads to the detailed representation of ground models (Baugrundmodelle). The relevant hazards (Gefährdungsbilder) can be easily identified on the basis of the ground models and possible concepts for measures can be than drawn up. This systematic approach leads to a robust excavation design even under the most difficult conditions in coventional or mechanized excavation.

In urban underground construction (stations, tunnels and facilities), tunneling methods that protect the the sensitive environment while maintaining appropriate safety factors must be strived for. In addition to conceptual considerations, complex numerical calculations are often required to estimate the extent of settlement as accurately as possible. With regard to the local residents, the stakeholders and the environment, we attach great importance to the sustainability of the planned and realized structures.

The subsurface is gaining more and more importance for large and often complex underground facilities, be it for hydropower plants or research facilities. For the design of caverns with large heights and widths, as well as deep shafts, the detailed study of geotechnical conditions and a deep understanding of the principles of rock mechanics are indispensable.

Complex underground facilities for research or community service facilities are part of our core business.

We are involved in the design of numerous laboratories for scientific use: it is also a mission for our company to contribute to the scientific community. We have historically been involved at Cern in Geneva (1981) and for the sub-nuclear physics laboratories under Gran Sasso (1985). In the recent years (2016-2022), we have been the leader of “HL-LHC Point 5” infrastructure design at Cern (Preliminary Design, Final Design, Detailed Design, Tender Design, Preparation of the tender based on FIDIC Redbook standards.
We are also involved in high-voltage underground connection projects.

In addition to numerous tunnel constructions using underground methods, various cut-and-cover tunnels extend our service portfolio in the field of near-surface tunnel construction. In these structures, the interactions of the existing ground and the new tunnel structure are of particular importance.

Tunnel safety measures are primarily aimed at preventing accidents and secondarily at minimizing the effects of an event. Both aspects are taken into account as decisive design objectives in the planning and realization of the operating and safety installations.

• Integral tests and fire tests allow the effectiveness of the installations to be verified.
• Regular training of operating and emergency personnel, audits and event simulations ensure a high level of personal and building protection.

For example, we carried out the electromecanical equipment of several important tunnels in Switzerland and are currently heavily involved with the equipment of the entire Gotthard Road tunnel system. In India, we are currently in charge of the equipment design of a new urban tunnel in Mumbai, as well as of various rail tunnels in the north of the country.

Ventilation systems are used on the one hand to ensure sufficient air quality under normal operating conditions and on the other hand to discharge smoke from the structure without endangering people in the event of fire. Ventilation is also a key element in the construction phase to ensure safe and efficient site management.

We carried out and imlemented the ventilation systems e.g. for the Pfändertunnel (Austria), the Mont Terri and Mont Russelin tunnels, the Vedeggio-Cassarate, the Melide-Grancia, the Mappo-Morettina and currently the entire Gotthard road tunnel system (all in Switzerland). In France, we are in charge of the ventilation renovation of the tunnels of the Boulevard Periferique du Nord de Lyon (BPNL), and in India the ventilation system of a new urban road tunnel in Mumbai has been designed by us.

We plan and implement electromechanical equipment for tunnels worldwide. We completely cover all departments from power supply to lighting, ventilation, control technology and building equipment, and offer complete, end-to-end design services from a single source.

We support tunnel operators in their day-to-day operations with in-depth expertise (databases for operation and maintenance, safety documentations, safety officers as defined by the EU Directive on Tunnel Safety 2004/54/EG).

With our core competencies of civil and electromechanical engineering, we offer project planning, design, and construction supervision services for technical buildings. The buildings can range from stations for operation and ventilation, for excavation and concrete structural works, to complete equipment installations. Whether underground (niches, shafts or buildings) or in the portal area, we cover the entire range of buildings.

Many infrastructure projects are almost at the lanned service life or no longer meet the new requirements for operation. Renovations, profile widening and repairs are an important part of our current work activity. We are happy to meet the challenges of construction on existing structures and under operation and develop customized solutions for our clients according to the required usage requirements (Nutzungsanforderungen).

Engineering services for the mining sector prioritize sustainability, ensuring that extraction processes have minimal environmental impact and make efficient use of resources.

Our commitment is oriented to implement advanced technologies and practices to safeguard both the surrounding ecosystem and mine workers. By emphasizing safety and eco-friendly solutions, our actions bridge the gap between resource demands and responsible stewardship of our planet.

We have many years of experience in the pre-treatment of weak rock or soft soil and the creation of sealing bodies in the protection of which tunnelling (conventional or TBM) can be carried out. Freezing, jet-grouting, systematic drainage and injections are examples of measures that we have planned and closely supervised during their realization and are therefore part of our core expertise.