MSc Students 2007-2008

Samuel Diem

Assessment of Hydraulic Conductivity at an Experimental Test Site at River Thur Using Hydraulic Tests on Different Scales

The project "Restored Corridor Dynamics" (ReCorD) of ETH and Canton Thurgau investigates, how interactions between River Thur and the ground water of the Thur valley alluvial gravel-and-sand aquifer (glaciofluvial outwash) are altered by river restoration measures. With the available Geoprobe® drilling equipment, we measure aquifer and river-bed hydraulic conductivity at different scales and with different methods. The goal of the master study is to identify groundwater flow paths and and residence times of river water infiltrating to ground water.

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Auro Lunghi

Analysis of an unstable rock mass on the San Bernadino route above Pian San Giacomo

In early June 2008 an overhanging, unstable rock mass located on the San Bernadino Route (Mesocco Plateau) will be removed by blasting, under the direction of the Tiefbauamt Graubunden. The planned event offers the opportunity for a student to make a comparative study looking at how rockmass characteristics change before and after blasting and its influence on its relative kinematic stability. Of special interest is the behavior of rock bridges pre and post blasting. Since this project must begin relatively early in 2008, a meeting between the student, supervisor and representatives of the Tiefbauamt GR is planned for January, where project objectives and a work plan will be jointly discussed.

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Christian Haug

Excavation Damaged Zone in the Opalinus Clay

The EZ-B Niche in the Mont Terri Underground Rock Laboratory generated an EdZ with significant reductions in seismic velocity but only very rare macroscopic fractures. In a recent PhD it was shown that damage and macroscopic fracturing in the EZ-B Niche face and the adjacent Gallery04 was strongly controlled by small foliation shears (tectonic shear zones parallel to foliation). One possible objective of this thesis is to investigate the mechanical properties of these tectonic shears through lab tests (direct shear, normal and shear stiffness). This would require to set up and test new lab equipment and collect new samples in the field.

Michael Ruppen

Geological Disposition and Failure Mechanisms of a Rock Slide Complex - Saas Tal, Wallis

This masters thesis aims to develop a detailed engineering geological investigation of a rock slide complex located in the Southern Saas Tal. Initial field work will aim at developing a landslide feature map (geomorphology) defining the boundaries and morphological characteristics of the complex. Detailed engineering geological characterization of the rock mass structure will be conducted utilizing both traditional mapping techniques as well as photogrammetric methods (Shape matrix) to identify features controlling the surface morphology and develop a structural model for evaluting potential failure modes and triggering mechanisms using both kinematic analyses and numerical simulations.

Ivo Schwenk

Interaction between spalling and swelling in the Gipskeuper – examination of a hypothesis

Swelling of anhydrite in tunnels within Gipskeuper in the Jura region causes serious problems during construction and maintenance. A hypothesis to explain the problem is that brittle failure especially in the invert causes extensional fractures and increases the hydraulic connectivity. Due to the increase of the free surface water infiltrates and induces the chemical swelling reaction from anhydrite to gypsum with a huge volume enhancement.
The main study area is the motorway tunnel Belchen in the eastern Swiss Jura. The double tube tunnel suffered large damage even during construction because of swelling of anhydrite.
The objective is to prove the existence of extensional fractures within the excavation damage zone at the invert by means of data interpretation and numerical simulations. Additionally the influence of heterogeneity on the stress path, fracture processes and consequently on swelling behavior will be investigated. The results of the modeled excavation damage zone will be compared with the measured invert heave.

Michael Sonderegger

Stress evaluation in support of the proposed new pressure tunnel of the Emossen Hydro-electric project extension

It is planned to increase the capacity of the Emosson hydroelectric facility by realizing a pump storage hydropower scheme between the lake Emosson and Vieux Emosson. Some stretches of tunnel complex will carry water under significant pressure, and it is important to assess whether the pressure is less than the minimum principal stress in the rock mass through which the tunnel passes. The goal of the MSc thesis is to conduct an evaluation of the state of stress around the planned pressure tunnel using all available information. The geological context of the planned pressure tunnel will also be important. The characterisation defined by the measurements will be compared with the predictions of various formulae that have been proposed in the literature to calculate the stress state in situations of major topography where no stress measurements are made.

Andreas Teuscher

The Engineering Geology Test Site at Mels (SG): Scale dependant geological and hydrogeological properties of the Verrucano Formation

The objective of this MSc thesis is a comprehensive field and lab study of the geological and hydrogeological conditions of the Verrucano formation at the ETH test site in Mels. The study includes drilling observation, core mapping, core photography, geophysical logging and hydrogeological borehole testing. Eventually lab testing on core including measurements with an automated core scanner can also be performed. Scientific questions to be addressed include matrix and fracture permeability and porosity from small to large scales (microscopic, core logging, borehole logging, crosshole testing).