modelling – Science@Bleßberghöhle

Karst modelling Schalkauer Platte

Posted on 10. May 202110. May 2021 by Norbert in Project

Project lead

FU Berlin, Institute of Geological Sciences – Dynamics of the Earth Group

Content

Development of a karst model for the area of the Schalkauer Platte and the tunnel area of the Blessberg cave. Tunnel constructions are potentially at risk from water migration through the rock. Particularly in highly permeable karst, the modelling of water pathways is of great importance for hazard assessment. How does the karstification behaviour change due to large underground structures? How does water movement change due to concrete placement? Does groundwater quality possibly suffer? What are the effects of changing water flow in the Blessberg cave (and in other caves)? These and many other questions will be addressed with karst modelling.

Results

Modelling of karstification

FU Berlin, Institute of Geological Sciences – Dynamics of the Earth Group

Posted on 10. May 202110. May 2021 by Norbert in Group

The group is analysing and modelling geodynamic processes that take place on and in the Earth, such as the development of aquifer systems (karstification, groundwater flow, …). Computer simulations are essentially used for this purpose.

A model for the simulationModell Ein Computermodell ist in der Regel eine Sammlung von vielen mathematischen Gleichungen, die verschiedene natürliche (physikalische, chemische, biologische) Vorgänge sehr gut mathematisch darstellen. Im Computer kann man das Modell mit verschiedenen Parameterwerten (z. B. verschiedene Häufigkeit von Klüften, verschiedene Temperatur) laufen lassen, wodurch man ein sehr gutes Verständnis der Zusammenhänge und Einflußfaktoren auf die zu untersuchenden Phänomene erhält. of karstification was developed and applied to the Blessberg cave.

Contact

Prof. Dr. Georg Kaufmann

Web Site

https://www.geo.fu-berlin.de/en/geol/fachrichtungen/geophy/index.html

Publications

Kaufmann, Georg; Romanov, Douchko

Modelling long-term and short-term evolution of karst in vicinity of tunnels Journal Article

In: Journal of Hydrology, vol. 581, pp. 124282, 2020.

Abstract | Links | BibTeX

@article{Kaufmann2020,

title = {Modelling long-term and short-term evolution of karst in vicinity of tunnels},

author = {Georg Kaufmann and Douchko Romanov},

doi = {10.1016/j.jhydrol.2019.124282},

year  = {2020},

date = {2020-02-01},

journal = {Journal of Hydrology},

volume = {581},

pages = {124282},

abstract = {Tunnel construction offers unique insights into the interior structure of rock massifs. Soluble rocks encountered during tunnel construction, however, pose a substantial challenge. Especially classical karst rocks such as limestone, dolostone, gypsum, and anhydrite are unpredictable during tunnel excavation. The enlarged voids created by the long-term dissolution of the soluble rocks in contact with water pose risks because of possible uncontrollable water inflow and of instability of the encountered cave voids, which often requires expensive remediation measures. We model the long-term development of karst features and the evolution of phreatic and epi-phreatic caves below the Schalkau Plateau in the Triassic limestone with a numerical karst evolution model. With hydrological boundary conditions derived from local meteorological data and karst springs, and a simplified model of the local lithology, our model predicts the increase in secondary permeability in the karst aquifer. Enlarged fracture zones develop at locations, where cave systems have been explored. Thus our long-term evolution model can successfully predict karst features in the Schalkau Plateau. Applying the karst evolution model on a short-term period, we assess the effect of consolidation measures taken to stabilise the tunnel cross section in vicinity of the Bleßberg Cave and its longer-term stability. Our model results suggest that flow through the cave section beneath the tunnel, which has been filled with concrete and blocks, is blocked and that during flood events the impounded water will accelerate the development of by-passes around the artificial infill.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

Close

Kaufmann, Georg; Romanov, Douchko

Karst and trains: The challenge of railway tunneling Proceedings Article

In: Geophysical Research Abstracts, pp. EGU2019-3554, 2019.

Abstract | Links | BibTeX

Modelling of karstification

Posted on 10. May 20213. June 2021 by Norbert in Results

Marwan, Norbert

Bleßberghöhle – Schatzkammer für die Wissenschaft Presentation

15.06.2022, (VdHK-Symposium: Wissenschaft unter Tage – Höhlenforschung im Dialog, Truckenthal (Germany)).

BibTeX

Kaufmann, Georg; Romanov, Douchko

Modelling long-term and short-term evolution of karst in vicinity of tunnels Journal Article

In: Journal of Hydrology, vol. 581, pp. 124282, 2020.

Abstract | Links | BibTeX

@article{Kaufmann2020,

title = {Modelling long-term and short-term evolution of karst in vicinity of tunnels},

author = {Georg Kaufmann and Douchko Romanov},

doi = {10.1016/j.jhydrol.2019.124282},

year  = {2020},

date = {2020-02-01},

journal = {Journal of Hydrology},

volume = {581},

pages = {124282},

abstract = {Tunnel construction offers unique insights into the interior structure of rock massifs. Soluble rocks encountered during tunnel construction, however, pose a substantial challenge. Especially classical karst rocks such as limestone, dolostone, gypsum, and anhydrite are unpredictable during tunnel excavation. The enlarged voids created by the long-term dissolution of the soluble rocks in contact with water pose risks because of possible uncontrollable water inflow and of instability of the encountered cave voids, which often requires expensive remediation measures. We model the long-term development of karst features and the evolution of phreatic and epi-phreatic caves below the Schalkau Plateau in the Triassic limestone with a numerical karst evolution model. With hydrological boundary conditions derived from local meteorological data and karst springs, and a simplified model of the local lithology, our model predicts the increase in secondary permeability in the karst aquifer. Enlarged fracture zones develop at locations, where cave systems have been explored. Thus our long-term evolution model can successfully predict karst features in the Schalkau Plateau. Applying the karst evolution model on a short-term period, we assess the effect of consolidation measures taken to stabilise the tunnel cross section in vicinity of the Bleßberg Cave and its longer-term stability. Our model results suggest that flow through the cave section beneath the tunnel, which has been filled with concrete and blocks, is blocked and that during flood events the impounded water will accelerate the development of by-passes around the artificial infill.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

Close

Kaufmann, Georg; Romanov, Douchko

Karst and trains: The challenge of railway tunneling Proceedings Article

In: Geophysical Research Abstracts, pp. EGU2019-3554, 2019.

Abstract | Links | BibTeX

The strength and speed of karstification depends on various parameters, such as water balance or the existing rocks. A karstification model was used to model how karstification had developed in the area of the Schalkauer Platte and how it will develop in the future.

The model shows regional differences in the karstification potential. Especially in the areas where the model calculated increased karstification, there are, indeed, more caves, including the Blessberg cave. The modelling of future karst development, especially in the area of the cave part under the tunnel that was blocked during tunnel construction, showed a substantial increase in karstification in this area, i.e., a faster widening of fissures and crevices (in the time frame of 100 to 200 years).