Barbara Schneider-Muntau
@uibk.ac.at
Computational and experimental soil mechanics
University of Innsbruck
RESEARCH, TEACHING, or OTHER INTERESTS
Engineering
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Lotte de Vugt, Thomas Zieher, Barbara Schneider‐Muntau, Mateo Moreno, Stefan Steger, and Martin Rutzinger
Wiley
AbstractThe development of better, more reliable and more efficient susceptibility assessments for shallow landslides is becoming increasingly important. Physically based models are well‐suited for this, due to their high predictive capability. However, their demands for large, high‐resolution and detailed input datasets make them very time‐consuming and costly methods. This study investigates if a spatially transferable model calibration can be created with the use of parameter ensembles and with this alleviate the time‐consuming calibration process of these methods. To investigate this, the study compares the calibration of the model TRIGRS in two different study areas. The first study area was taken from a previous study where the dynamic physically based model TRIGRS was calibrated for the Laternser valley in Vorarlberg, Austria. The calibrated parameter ensemble and its performance from this previous study are compared with a calibrated parameter ensemble of the model TRIGRS for the Passeier valley in South Tyrol, Italy. The comparison showed very similar model performance and large similarities in the calibrated geotechnical parameter values of the best model runs in both study areas. There is a subset of calibrated geotechnical parameter values that can be used successfully in both study areas and potentially other study areas with similar lithological characteristics. For the hydraulic parameters, the study did not find a transferable parameter subset. These parameters seem to be more sensitive to different soil types. Additionally, the results of the study also showed the importance of the inclusion of detailed information on the timing of landslide initiation in the calibration of the model.
Mona Siahkouhi, Christoph Pletzer, Thomas Marcher, and Barbara Schneider-Muntau
Informa UK Limited
Xiaoru Dai, Barbara Schneider-Muntau, Julia Krenn, Christian Zangerl, and Wolfgang Fellin
MDPI AG
The Ludoialm landslide, which is located in the municipality of Münster in Tyrol, Austria, represents a large-scale translational landslide in glacial soil sediments characterised by an exceptionally low inclined basal shear zone of only 12°. Although a temporal coincidence between meteorological events and slope displacement is obvious, the hydromechanical coupled processes responsible for the initial landslide formation and the ongoing movement characteristics have not yet been identified. This article provides a comprehensive analysis of the predisposition factors and the initial failure mechanism of this landslide from geological and geotechnical perspectives. We use a prefailure geometry of the cross section to simulate the initial slope failure process by a limit equilibrium analysis (LEA), a strength-reduction finite element method (SRFEM), and a finite element limit analysis (FELA). The shape and location of the computationally obtained basal sliding zone compare well with the geologically assumed one. Based on the computational study, it turns out that a high groundwater table probably caused by snow melting in combination with different permeabilities for the different layers is needed for the formation of the exceptionally low inclined basal shear zone. This paper presents the failure mechanism of the Ludoialm landslide and discusses the role of the shear band propagation in the process of slope destabilization.
Jan Pfeiffer, Thomas Zieher, and Barbara Schneider‐Muntau
Wiley
AbstractSlow‐moving deep‐seated landslides are characterised by continuous deformation, constantly changing topography and sliding‐mass geometry. Deformation rates are predominantly controlled by temporal dynamics of pore pressure. Progressing movements typically cause an over‐steepening of a landslide's foot, making these areas more susceptible to secondary slope failures and piggyback slides that, once they occur, change the geometric boundary conditions of a slope. This study presents an integrated topographic monitoring and geomechanical modelling approach, which is suitable for both model‐based replication of the landslide's hydro‐meteorological drivers and assessment of the long‐term effect of topographic changes on the stability behaviour of a large deep‐seated landslide. Parametrised at the Vögelsberg landslide (Tyrol, Austria) the integrated approach quantified considerable mass relocations between 2007 and 2020 at the landslide's foot and assessed respective effects on slope stability. Additionally, scenarios of past and future topographies were reconstructed and projected. Mass relocations of the order of 25 000 m3 were assessed between multiple airborne laser scanning acquisitions covering a period of 13 years. Based on annual uncrewed aerial vehicle laser scanning campaigns, area‐wide 3D displacements were analysed, exceeding a magnitude of 200 cm a−1 at small parts (2.500 m2) on the steeper foot of the active landslide. The main landslide body (0.28 km2) moves considerably slower with movements of 2–10 cm a−1. Besides spatio‐temporally varying hydrological drivers, topographic changes can have a severe impact on slope stability and therefore modify the spatiotemporal activity of the landslide. It is shown that, besides the hydrometeorological drivers, the varying elevation of the landslide's toe is a key parameter determining the long‐term trend of slope stability. With the presented approach the formation and evolution of the Vögelsberg landslide can be understood and explained.
Roshanak Shafieiganjeh, Marc Ostermann, Barbara Schneider-Muntau, and Bernhard Gems
Elsevier BV
Barbara Schneider‐Muntau, Xiaoru Dai, and Wolfgang Fellin
Wiley
AbstractCalculation approaches, shear strength approaches, material parameters and external influences have a significant impact on the results of slope stability analyses. This influence can be quantified as influence on the safety factor in sensitivity analyses. As expected, a lower shear strength of the soil or a higher groundwater flow through a slope lead to lower factors of safety. In the two case studies considered here, it is evident that the parameter with the highest sensitivity of the safety factor is not unique. This most influencing parameter depends on the boundary conditions and the geometry of the landslide. In addition to the safety factor, the above parameters also strongly influence the geometry of the failure mechanism. Here, for example, different permeability coefficients for stratified soil and the consideration of a nonlinear shear strength criterium show significant changes in the failure geometry. Therefore, the modelled failure geometry has to be considered in addition to an certain safety factor for the validation of a landslide modelling.
Andrea Franco, Jasper Moernaut, Barbara Schneider-Muntau, Michael Strasser, and Bernhard Gems
Elsevier BV
Andrea Franco, Barbara Schneider-Muntau, Nicholas J. Roberts, John J. Clague, and Bernhard Gems
MDPI AG
In this work, a simple methodology for preliminarily assessing the magnitude of potential landslide-induced impulse waves’ attenuation in mountain lakes is presented. A set of metrics is used to define the geometries of theoretical mountain lakes of different sizes and shapes and to simulate impulse waves in them using the hydrodynamic software Flow-3D. The modeling results provide the ‘wave decay potential’, a ratio between the maximum wave amplitude and the flow depth at the shoreline. Wave decay potential is highly correlated with what is defined as the ‘shape product’, a metric that represents lake geometry. The relation between these two parameters can be used to evaluate wave dissipation in a natural lake given its geometric properties, and thus estimate expected flow depth at the shoreline. This novel approach is tested by applying it to a real-world event, the 2007 landslide-generated wave in Chehalis Lake (Canada), where the results match well with those obtained using the empirical equation provided by ETH Zurich (2019 Edition). This work represents the initial stage in the development of this method, and it encourages additional research and modeling in which the influence of the impacting characteristics on the resulting waves and flow depths is investigated.
Xiaoru Dai, Barbara Schneider-Muntau, Wolfgang Fellin, Andrea Franco, and Bernhard Gems
MDPI AG
On 17 October 2015, a large-scale subaerial landslide occurred in Taan Fiord, Alaska, which released about 50 Mm3 of rock. This entered the water body and triggered a tsunami with a runup of up to 193 m. This paper aims to simulate the possible formation of a weak layer in this mountainous slope until collapse, and to analyze the possible triggering factors of this landslide event from a geotechnical engineering perspective so that a deeper understanding of this large landslide event can be gained. We analyzed different remote-sensing datasets to characterize the evolution of the coastal landslide process. Based on the acquired remote-sensing data, Digital Elevation Models were derived, on which we employed a 2D limit equilibrium method in this study to calculate the safety factor and compare the location of the associated sliding surface with the most probable actual location at which this landslide occurred. The calculation results reflect the development process of this slope collapse. In this case study, past earthquakes, rainfall before this landslide event, and glacial melting at the toe may have influenced the stability of this slope. The glacial retreat is likely to be the most significant direct triggering factor for this slope failure. This research work illustrates the applicability of multi-temporal remote sensing data of slope morphology to constrain preliminary slope stability analyses, aiming to investigate large-scale landslide processes. This interdisciplinary approach confirms the effectiveness of the combination of aerial data acquisition and traditional slope stability analyses. This case study also demonstrates the significance of a climate change for landslide hazard assessment, and that the interaction of natural hazards in terms of multi-hazards cannot be ignored.
Sinah Kilian, Hugo Ortner, and Barbara Schneider-Muntau
Elsevier BV
Barbara Schneider-Muntau, Gertraud Medicus, Jacques Desrues, E. Andò, and Gioacchino Viggiani
Springer International Publishing
Gertraud Medicus, Manuel Bode, Franz Tschuchnigg, and Barbara Schneider-Muntau
Springer International Publishing
Barbara Schneider‐Muntau
Wiley
AbstractTo quantify the interaction between structures and creeping slopes, 3D calculations under consideration of a time‐dependent material behaviour are necessary. In this paper 3D finite element calculations are performed on a hypothetical creeping slope. The time‐dependent material parameters are determined by back calculation on a slope without any structures. Subsequently, the influence of a retaining wall and of a tunnel structure built in the creeping slope are investigated. The results of the modelling show that the structures locally decrease the creeping velocity of the slope. The influence of the tunnel structure is more pronounced due to its spatial extension. At the same time the stresses on the structures increase over time. Linear time‐dependent material models do not consider the hydrostatic pressure in their formulation. Non‐linear time‐dependent material models, which are based on soil mechanical principles and which take the hydrostatic pressure into account, are therefore better suited to represent the time‐dependent soil‐structure interaction.
Andrea Franco, Jasper Moernaut, Barbara Schneider-Muntau, Michael Strasser, and Bernhard Gems
Copernicus GmbH
Abstract. This study aims to test the capacity of Flow-3D regarding the simulation of a rockslide-generated impulse wave by evaluating the influences of the extent of the computational domain, the grid resolution, and the corresponding computation times on the accuracy of modelling results. A detailed analysis of the Lituya Bay tsunami event (1958, Alaska, maximum recorded run-up of 524 m a.s.l.) is presented. A focus is put on the tsunami formation and run-up in the impact area. Several simulations with a simplified bay geometry are performed in order to test the concept of a “denser fluid”, compared to the seawater in the bay, for the impacting rockslide material. Further, topographic and bathymetric surfaces of the impact area are set up. The observed maximum run-up can be reproduced using a uniform grid resolution of 5 m, where the wave overtops the hill crest facing the slide source and then flows diagonally down the slope. The model is extended along the entire bay to simulate the wave propagation. The tsunami trimline is well recreated when using (a) a uniform mesh size of 20 m or (b) a non-uniform mesh size of 15 m × 15 m × 10 m with a relative roughness of 2 m for the topographic surface. The trimline mainly results from the primary wave, and in some locations it also results from reflected waves. The denser fluid is a suitable and simple concept to recreate a sliding mass impacting a waterbody, in this case with maximum impact speed of ∼93 m s−1. The tsunami event and the related trimline are well reproduced using the 3D modelling approach with the density evaluation model available in Flow-3D.
Tobias Cordes, Barbara Schneider‐Muntau, Chris Reinhold, Sebastian Grüllich, Christian Himmelsbach, and Gerhard Wehrmeyer
Wiley
AbstractForecasts made during tunnelling of the daily advance, to control the machine, specify the lining and verify system behaviour are of great importance for safety and for the success of the whole project. In practice, such forecasts are obtained in deep tunnels by probe drilling, leading to downtime periods and by analog/digital face documentation with shorter downtime periods. Measurement and evaluation of rock mass cutting at the cutterhead of the TBM enables continuous monitoring without downtime. From the spatial distribution of the disc forces, basic geological/geotechnical information about the tunnel face can be derived. In addition, this data is valuable for load monitoring and monitoring the condition of the discs to determine the optimal changing time. This contribution deals with a geological‐geotechnical interpretation of the disc forces of the open TBM on contract H33 Tulfes‐Pfons of the Brenner Base Tunnel. The spatially distributed disc forces are evaluated and compared with the geological documentation.
Gertraud Medicus, Barbara Schneider-Muntau, and Dimitrios Kolymbas
Springer Science and Business Media LLC
Franz Tschuchnigg, Gertraud Medicus, and Barbara Schneider-Muntau
EDP Sciences
The results of slope stability analysis are not unique. Different factors of safety are obtained investigating the same slope. The differences result from different constitutive models including different failure surfaces. In this contribution, different strength reduction techniques for two different constitutive models (linear elastic - perfectly plastic model using a Mohr-Coulomb failure criterion and barodesy) have been investigated on slope stability calculations for two different slope inclinations. The parameters for Mohr – Coulomb are calibrated on peak states of element tests simulated with barodesy for different void ratios. For both slopes the predictions of the factors of safety are higher with barodesy than with Mohr-Coulomb. The difference is to some extend explained by the different shapes of failure surfaces and thus different values for peak strength under plane strain conditions. The plane strain predictions of Mohr-Coulomb are conservative compared to barodesy, where the failure surface coincides with Matsuoka-Nakai.
T. Cordes, C. Reinhold, K. Bergmeister, B. Schneider-Muntau, and I. Bathaeian
CRC Press
Gertraud Medicus and Barbara Schneider-Muntau
MDPI AG
Recent experimental studies showed that shear band development starts at the beginning of triaxial tests. In experimental testing, it is impossible to obtain a soil sample with a homogeneous void ratio. Therefore, a homogeneous deformation, i.e., an element test, is questionable well before the peak. In this article we carry out finite element simulations of fine-meshed biaxial tests with the constitutive model barodesy, where the stress rate is formulated as a function of stress, stretching and void ratio. The initial void ratio in the simulations is normally distributed over all elements in a narrow range. In this article, we evaluate the pre-peak shear band development. We further compare stress paths and stress-strain curves of the biaxial test of relevant elements (e.g., in- and outside the shear band) with the results of the average response of all elements. We show how the response in an element test differs from the average response of the fine-meshed test. We present the resulting potential for understanding (early) shear band development and stress-strain behaviour in a biaxial test: The inhomogeneous void ratio distribution in a sample favours early shear band development. This effect is modelled with barodesy. The obtained stress paths and stress-strain curves show that the maximum deviatoric stress is higher in the element test than it is in the average response of the fine-meshed test.
Barbara Schneider-Muntau and Iman Bathaeian
Springer Science and Business Media LLC
Barbara Schneider‐Muntau, Chris Reinhold, Tobias Cordes, Iman Bathaeian, and Konrad Bergmeister
Wiley
AbstractLongitudinal displacement profiles describe the displacement history during tunnel excavation, including that occurring ahead of the tunnel face. These deformations have an influence on the structural design of tunnel support. Theoretical approaches are used to estimate these deformations. However, as the approaches are based on assumptions, they should be applied with caution, particularly in case of deep tunnels. Therefore, experimentally determined longitudinal displacement profiles provide a valuable data basis for validation of the approaches. This study compares 40 m long horizontal chain inclinometer measurements in two lithologies in the exploration tunnel of the Brenner Base Tunnel with theoretically calculated profiles. The chain inclinometers were installed above the tunnel before the start of tunnelling. A measured radial displacement profile was created for each round, the statistical mean value curve was calculated and finally compared with the theoretical approaches. The measurement results show good qualitative agreement ahead of the tunnel face.
Barbara Schneider‐Muntau, Fabian Schranz, and Wolfgang Fellin
Wiley
AbstractThe shear strength of soils, commonly represented in terms of friction angle and cohesion, is an important input parameter for all geotechnical calculations. It can be assessed in the laboratory for example by triaxial tests. From the laboratory test results, the characteristic values for friction angle and cohesion have to be determined – according to the standards – as conservative estimation of the mean value. Usually the shear strength is calculated as linear regression in the s‐t‐representation. This leads to slightly higher values than the evaluation in the more appropriate σ1‐σ2‐representation. Friction angle and cohesion are usually assumed to be statistically independent variables, resulting in unrealistically low characteristic shear strengths. Friction angle and cohesion are obviously correlated, since they are parameters of one linear regression. Confidence hyperbolas can be determined by taking into account the statistical dependency of friction angle and cohesion. A linearization of the confidence hyperbolas provides an upper and lower limit of the shear parameters. Typical examples are used to demonstrate the determination of the characteristic shear strength from the laboratory test results with the above mentioned approaches. Moreover we show, that the characteristic shear strength can be determined more precisely if more lateral stress levels (e.g. six) are performed instead of the conventional three levels.
Barbara Schneider-Muntau, Gertraud Medicus, and Wolfgang Fellin
Elsevier BV
Thomas Zieher, Barbara Schneider-Muntau, and Martin Mergili
Springer Science and Business Media LLC
Thomas Zieher, Martin Rutzinger, Barbara Schneider-Muntau, Frank Perzl, David Leidinger, Herbert Formayer, and Clemens Geitner
Copernicus GmbH
Abstract. Physically based modelling of slope stability on a catchment scale is still a challenging task. When applying a physically based model on such a scale (1 : 10 000 to 1 : 50 000), parameters with a high impact on the model result should be calibrated to account for (i) the spatial variability of parameter values, (ii) shortcomings of the selected model, (iii) uncertainties of laboratory tests and field measurements or (iv) parameters that cannot be derived experimentally or measured in the field (e.g. calibration constants). While systematic parameter calibration is a common task in hydrological modelling, this is rarely done using physically based slope stability models. In the present study a dynamic, physically based, coupled hydrological–geomechanical slope stability model is calibrated based on a limited number of laboratory tests and a detailed multitemporal shallow landslide inventory covering two landslide-triggering rainfall events in the Laternser valley, Vorarlberg (Austria). Sensitive parameters are identified based on a local one-at-a-time sensitivity analysis. These parameters (hydraulic conductivity, specific storage, angle of internal friction for effective stress, cohesion for effective stress) are systematically sampled and calibrated for a landslide-triggering rainfall event in August 2005. The identified model ensemble, including 25 behavioural model runs with the highest portion of correctly predicted landslides and non-landslides, is then validated with another landslide-triggering rainfall event in May 1999. The identified model ensemble correctly predicts the location and the supposed triggering timing of 73.0 % of the observed landslides triggered in August 2005 and 91.5 % of the observed landslides triggered in May 1999. Results of the model ensemble driven with raised precipitation input reveal a slight increase in areas potentially affected by slope failure. At the same time, the peak run-off increases more markedly, suggesting that precipitation intensities during the investigated landslide-triggering rainfall events were already close to or above the soil's infiltration capacity.