Geowissenschaften
Swelling Rocks, Swelling Processes, Anhydritic Claystones, Anhydrite Dissolution, Gypsum Precipitation, Self-Sealing
Anhydritic claystones are highly problematic for underground construction because of their swelling ability: When the rock comes into contact with water, the rock volume expands due to swelling of both clay as well as anhydrite. When the expansion is restricted, e.g., by an invert arch in tunneling, the swelling rocks can exert high pressures on the lining and damage the structure. The swelling behavior of purely argillaceous rock (containing solely swelling clays and no anhydrite) can be attributed mainly to osmotic processes and is well understood for the conceptual design of tunnels, as opposed to the swelling of anhydrite, where considerable knowledge gaps exist.
Tunnelling, Squeezing, Schistosity, Heterogeneity, Analytical Solution, Numerical Modelling, Segmental Lining
The magnitude of squeezing deformations in tunnelling often varies over short distances, even if there is no obvious change in the construction method, in the depth of cover, in the lithology or rock structure. As long as the reasons for the variability are not known, the tunnelling-induced convergences cannot be predicted with sufficient reliability. Reliable predictions, however, are important for determining the temporary support or the excavation diameter. Otherwise, large-scale tunnel repairs may be necessary, which can cause delay and additional costs due to remedial actions as well as due to the enforced interruption of other operations in progress at the same time.
Silty Sand, Dynamic Behaviour, Earthquake Engineering, Basin
Effects, Soil Structure Interaction, Alpine Valleys, Seismic Monitoring,
Dams
Gravel Columns, Bearing Capacity, Soil Conditions, Soil Characteristics, Lacustrine Clay
Construction on soft soils is always accompanied by the risk of significant, time-dependent settlement and bearing capacity failure. As technical knowledge has advanced, optimised ground improvement has offered significant economic advantages in reducing net settlement and resisting failure by installation of more flexible and cost-effective stone columns or sand compaction piles in the ground, rather than more rigid inclusions such as steel or concrete piles. The stiffness and strength of the subsoil around the columns is greater, and the consolidation time is reduced through shorter (radial) drainage paths.Tunnelling, Tunnel Jacking, Ground Stability, MC Model, MCC Model
This thesis investigates the problem of time-dependent stability of geotechnical structures (such as trenches or tunnels) in medium- to low-permeability water-bearing grounds, typically clayey or silty soils. The peculiarity of these soils is that they respond to excavation with a delay. The time-dependency can be traced back to the swelling process triggered by the dissipation of the excavation-induced negative excess pore pressures. Unstable conditionsmay necessitate improvement or reinforcement of the ground or the application of a support (e.g. by compressed air or pressurized bentonite slurry in the case of tunnel face). As such measures may present economical and operational disadvantages, the question of whether and for how long the excavation can remain stable without support is of great practical relevance. The stand-up time (time lapsing between end of the excavation and the occurrence of failure), and thus the feasibility of refraining from ground reinforcement, improvement or support, depends essentially on soil strength and permeability.Rohstoffnutzung, Rohstoffabbau, Mineralien, Erze, Steine und Erden, Metalle, Industriemineralien, Seltene Erden, Salze, Kies, Kohle, Erdgas, Bergbau, Ökotoxikologie
Kupfer für Stromkabel, Erdöl zum Heizen, Silber für Schmuck und Zink im Auto – mineralische Rohstoffe sind in unserem Alltag allgegenwärtig. Schon früh haben die Menschen mineralische Rohstoffe genutzt. Kenntnisse über Vorkommen und Anwendungsmöglichkeiten haben von jeher einen Vorteil bedeutet und oft Reichtum und Macht gefördert. Und auch heute sind Rohstoffe für viele Länder ein wichtiger Wirtschaftsfaktor. Die Verfügbarkeit von Rohstoffen ist für uns selbstverständlich und der weltweite Verbrauch nimmt stetig zu. Was sind die Folgen unserer zunehmenden Nutzung dieser nicht erneuerbaren Ressourcen? Welche Herausforderungen kommen auf uns zu?
Rock Pressure, Tunnel, Tunnelling, Gotthard, Gibraltar Tunnel
Advance Drainage, Drainage Boreholes, Tunnel, Face Stability,
Limit Equilibrium, Fault Zone, Drainage Capacity, Equivalent Hydraulic
Conductivity, Borehole Casing, Lead-Time, Groundwater Drawdown, Settlement, Inflow, Grouting Body, Displacement, Characteristic Line
Weather Research, Meteorology, Atmospheric Sciences
In 2016 the Swiss Society for Meteorology (Schweizerische Gesellschaft für Meteorologie, SGM) celebrates its 100th anniversary. The idea of this book is to give an overview of what has happened in the field of atmospheric sciences in Switzerland since the first systematic long-term meteorological observations until today.
Endlager, Entsorgungslösung, Resilienz, Sicherheitsrisiko, Atommüll
Die Entsorgung hochradioaktiver Abfälle ist ein anspruchsvolles Vorhaben. Wird dauerhafte Sicherheit für Menschen und Umwelt angestrebt, müssen die Abfälle nach heutiger Auffassung über einen Zeitraum von einer Million Jahren oder länger von der Biosphäre abgeschlossen werden. Ist es möglich, ein solches Ziel zu erreichen?
Science, Transformation, Evolution, Physics, Chmistry, Biology, Geology, Astronomy, Culture
The development of science
over the course of many centuries has shown that there are things in our
universe which took incredibly long to form, such as planets or
galaxies. While, in contrast, there are processes, for example inside
our body, which happen so incredibly fast that they are beyond our
ability to fully comprehend. Using examples from different time periods
or timescales we aim to give you deeper insight, both visually and with
text, into some of the most amazing physical events, cultural
developments and biological processes from life. These examples are
brought together using three intertwined themes: life, light, and
science.
Landslide, Mudslide, Soil Mechnics, Hydraulic, Rhine, Rüdlingen
Landslides triggered by rainfall cause significant damage to
infrastructure annually and affect many lives in several parts of the
world, including Switzerland. These landslides are initiated by a
decrease in the effective stresses, and hence the shear strength of the
soil, as a result of the increase in pore water pressure.
Flood Protection, Rhone, Failure Mechanism, Overflow
Knowledge of the performance of river dykes during flooding is necessary when designing governmental assistance plans aimed to reduce both casualties and material damage. This is especially relevant when floods have increased in their frequency during the last decades, together with the resulting material damage and life costs.
Braunkohlebergbau, Altlasten, Tonboden, Bodenverbesserung
Double porosity soil is characterised by a soil continuum containing two distinct porosities. Typically, this consists of macro-grains (lumps) of soil that have an internal porosity defined as the intragranular porosity. The spaces between lumps are identified as intergranular voids that give rise to the intergranular porosity.
Permafrost, Rock Glacier, Crawling Motion, Slope Instability, Geotechnical Engineering
Alpine permafrost exists at high altitude at lower latitudes, such as in the Swiss Alps. Accelerating climate change, including rising mean annual air temperature and extreme rainfall conditions in alpine regions induces permafrost degradation.
Plattentektonik, Geologie, Gebirgsbildung, Alpen
Die dritte Auflage enthält neu ein Kapitel mit Cartoons von Mike van Audenhove: "Alpen by Mike".
Dieses Buch nimmt Sie mit auf eine geologische Zeitreise durch die
Schweiz. Erkennen Sie die Zusammenhänge zwischen Plattentektonik und
Gebirgsbildung am Beispiel der Alpen und des Juras. Erfahren Sie, wie
Sedimentgesteine als Archive zur Geschichte eines vergangenen Ozeans
sowie zur Entstehung eines Gebirges dienen.
Hochwasserschutz, Wasserretention, Rhone, Geotechnik
Die Hochwasserereignisse der letzten Jahrzehnte haben die Grenzen des Hochwasserschutzes deutlich ans Licht gebracht. Die Analyse der Auswirkungen von Klimaänderungen lässt zudem eine Erhöhung des Hochwasserrisikos befürchten. Viele Flussdämme als wichtiger Bestandteil des Hochwasserschutzes stammen aus dem 19. Jahrhundert und entsprechen nicht mehr dem heutigen Stand der Technik. Der Handlungsbedarf ist gross und es müssen Prioritäten entsprechend dem Gefährdungspotenzial gesetzt werden. In dieser Hinsicht sind zusätzliche Kenntnisse vom Verhalten der Flussdämme unter wiederholter Hochwasserbelastung und wechselnder Witterung notwendig.
Geothermics, Energy Supply, Electricity Generation
Switzerland's Energy Strategy 2050 requires energy efficiency to be substantially improved, the proportion of fossil fuels in the energy supply to be considerably reduced, and nuclear power to be phased out, while meeting highly ambitious climate protection targets. One of the core implications is the need for a massive increase of the use of renewable sources for electricity generation.
Tunnelling, Claystones, Gypsum Keuper, Swelling Process
Sulphatic claystones are among the most problematic rocks in tunnelling due to their distinctive swelling properties. They are known to have caused severe damage, for example, to numerous tunnels excavated in the Gypsum Keuper formation. The repairs were extremely costly and time-consuming, and often provided only a temporary solution. The setbacks experienced in tunnelling through Gypsum Keuper may be attributed, among other things, to our limited knowledge of the macroscopic principles governing the swelling process and the underlying microscopic mechanisms.
Schweiz, Berggebietspolitik, Alpendiskurs, Berggebietsentwicklung, Alpenkonvention, Alpentransversale
Die Berge sind seit über 150 Jahren ein bedeutendes Thema in der Schweizer Politiklandschaft. Seit Mitte des 19. Jahrhunderts prägen sie massgeblich das Nationalbewusstsein, stellen eine wichtige touristische Ressource dar und waren insbesondere seit den 1920er-Jahren viele Male Gegenstand der öffentlichen Politik sowie unzähliger Kontroversen.