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The rock mass must be described and investigated in detail for the professional project planning and execution of underground structures. Here geologists and engineers must work closely together.

Construction of the Gotthard Base Tunnel
Construction of the Gotthard Base Tunnel
© AlpTransit Gotthard AG


Tunnels can be regarded as real masterpieces in the underground. One requires extensive geological data and forecasts on the rock mass and groundwater conditions for a successful underground construction. A construction site’s rock mass is designated as loose or solid rock, according to various SIA standards and recommendations, in the domain of an underground construction project. This includes all of its ingredients e.g., groundwater, gas and contamination.

Rock mass characterization: fundamentally important!

The characteristics of the subsurface are particularly important regarding the behavior of a cavity to be constructed such as galleries, tunnels or caverns. It is essential how the rock behaves during the excavation process and what effects can be observed on the surface and the environment.

The rock mass is composed of various soil and rock layers. Its hydrological and mechanical properties play a major role. Because these properties can be very heterogeneous as a function of the geological context, the previous geological assessments and geotechnical characterizations of the rock mass represent an important basis for each construction project.

In Switzerland, the geological activities in the framework of underground construction are described in detail in the standards SIA 197, SIA 198, SIA 199 as well as SIA 106.

Tunnelling: Switzerland at the forefront

Here you can find information about ongoing or achieved tunnelling projects in Switzerland:

Who is who

The most important players on the topic geology in underground construction at a glance.

The following institutes and commissions are important contacts for theoretical and research orientated aspects: 

Many geological consultancies conduct investigations for underground construction. The address directory of the Swiss geosciences offers a canton-specific list:
Geoscience Switzerland

Im Jahr 2013 wurde die Arbeitsgruppe Tunnelforschung AGT mit der Benennung des Präsidenten durch den Direktor des Bundesamtes für Strassen aktiviert. Sie hat die Aufgabe, den Forschungsbereich Tunnel innerhalb der Forschung im Strassenwesen abzudecken.

Arbeitsgruppe Tunnelforschung AGT

Founded in 1974, the International Tunnelling and Underground Space Association (ITA) aims at encouraging the use of the subsurface for a broad public benefit and promoting advances in planning, design, construction, maintenance and safety of tunnels and underground space.

International Tunnelling and Underground Space Association ITA/AITES

Address directory of the Swiss geosciences
Geoscience Switzerland

Institute for Geotechnical Engineering, ETH Zürich
Wolfgang-Pauli-Str. 15
ETH Zürich, HIL C 13.2
CH-8093 Zürich

Tel. +41 44 633 25 25
Website (English)

The Institute for Geotechnical Engineering deals with soil and rock mechanics, clay minerals, geotechnical engineering and geo-environmental engineering. The institute is responsible for teaching and research, has highly specialized laboratories and field equipment at their disposal and offers various services.

Engineering Geology of ETH Zürich
ETH Zürich
Geologisches Institut, Ingenieurgeologie
Sonneggstrasse 5
CH-8092 Zürich

Tel. +41 44 632 36 65
Fax +41 44 632 10 80
Website (English)

The group for Engineering Geology is part of the Geological Institute of ETH Zürich. It researches the hydraulic and mechanical processes in fractured rock masses. The studies do not remain mere pure research, but are implemented daily in the fields of tunneling, natural hazards, geothermal energy or the sustainable use of groundwater. 

Laboratory of Experimental Rock Mechanics at EPF-Lausanne (LEMR)
(Laboratoire expérimental de mécanique des roches)

GC D1 401 (Building GC)

Station 18
CH-1015 Lausanne

Tel. +41 21 69 32372
Website (Englisch)

The Laboratory of Experimental Rock Mechanics at EPFL (LEMR) belongs to the School of Architecture, Civil and Environmental Engineering (ENAC). It provides research, teaching and services related to rock mechanics, rock physics, deep reservoir characterisation and coupled thermo-hydro mechanical processes in reservoirs, as well as engineering geology topics such as tunnelling and underground constructions.



You can find additional contact addresses on the Construction Site page.


The geological prognosis for underground constructions must provide all data about rock mass and groundwater conditions in sufficient quality that is required for project planning, execution and use of the structure. The prognosis occurs gradually.

The following are to be considered with an investigation and assessment of rock mass data:

  • geological and hydrogeological conditions
  • rock and soil mechanics properties
  • morphology
  • seismicity
  • natural hazards (portal areas)
  • contamination of the ground
  • gas flows
  • rock temperature
  • reusability of excavated material

The rock mass description contains the authoritative information and describes:

  • geological, hydrogeological and geotechnical maps including descriptive literature
  • hazard maps of portal areas (avalanches, rockfalls, landslides, water hazards) • aerial photographs
  • contaminated site register
  • databases and archives
  • information from neighboring exploration work
  • findings from neighboring or comparable project plans and sites


Swiss Tunnel-Database

Construction & Technology