Computational Geodynamic, Geotechnics and Geomechanics

A special issue of Geosciences (ISSN 2076-3263). This special issue belongs to the section "Geomechanics".

Deadline for manuscript submissions: 15 June 2024 | Viewed by 1669

Special Issue Editors


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Guest Editor
1. Department of Earth Sciences, Uppsala University, Uppsala, Sweden
2. Rock Engineering and Geology Department, Rejlers AB, Stockholm, Sweden
Interests: volcano deformation; volcano stresses; crustal displacements; volcano unrest; geodetic data; numerical modelling
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Guest Editor
Department of Earth Sciences, Royal Holloway University of London, Egham TW20 0EQ, UK
Interests: volcanotectonics; seismotectonics; tectonophysics; rock mechanics; structural geology; reservoir modelling; hydrogeology; fluid transport in reservoirs; thermodynamics/statistical mechanics of linements and networks

Special Issue Information

Dear Colleagues,

Computational geodynamics, geotechnics, and geomechanics are important fields of study that focus on the use of computer-based numerical methods to model and analyse geodynamic, geotechnical, and geomechanical problems in civil, energy, geological, and mining engineering. This field is a sub-discipline of computational mechanics with a focus on geosciences and includes various approaches such as finite element, finite difference, and discrete element methods. These methods have been used to solve a range of geotechnical and geomechanical problems, including foundation design, slope stability, tunnelling, and mining.

The finite element method is a numerical technique used to model and solve complex geodynamic, geotechnical, and geomechanical problems. The method involves dividing a complex structure or soil mass into a finite number of smaller, simpler elements, each with its own set of equations describing its behaviour. These equations are then solved using matrix algebra to obtain a solution to the entire system. The FEM has been widely used to analyse a variety of geotechnical problems, including slope stability, foundation design, tunnelling, and mining. The finite difference method is another computational technique used to model and solve geodynamic, geotechnical, and geomechanical problems. This method involves dividing a complex domain into a finite number of smaller cells, each with its own set of equations describing its behaviour. The equations are then solved using iterative methods to obtain a solution to the entire system. The FDM has been used to analyse a range of geotechnical problems, including soil–structure interaction, rock mechanics, and groundwater flow. The discrete element method is a numerical technique that models the behaviour of a granular material as a collection of individual particles. The method involves simulating the motion and interaction of each particle under the influence of external forces, such as gravity or applied loads. The DEM has been used to analyse a range of geoscientific problems, including rock fragmentation, blasting, and soil compaction.

These methods are used to optimise the design of structures or mining operations, by minimising costs or maximising performance applied in a range of geotechnical and geomechanical problems, including slope stability analysis, foundation design, and mine planning.

Dr. Mohsen Bazargan
Prof. Dr. Agust Gudmundsson
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Geosciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • slope stability
  • tunnel stability
  • dyke propagations
  • permeability evolution
  • hydraulic fracturing with viscous flow
  • mine planning

Published Papers (1 paper)

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Research

20 pages, 7735 KiB  
Article
Modeling the Stiffening Behavior of Sand Subjected to Dynamic Loading
by Majd Ahmad and Richard Ray
Geosciences 2024, 14(1), 26; https://doi.org/10.3390/geosciences14010026 - 22 Jan 2024
Viewed by 1221
Abstract
In geotechnical engineering, dynamic soil models are used to predict soil behavior under different loading conditions. This is crucial for many dynamic geotechnical problems related to earthquakes, train loading and machine foundation design. Researchers agree that under dry or drained conditions, cohesionless soils [...] Read more.
In geotechnical engineering, dynamic soil models are used to predict soil behavior under different loading conditions. This is crucial for many dynamic geotechnical problems related to earthquakes, train loading and machine foundation design. Researchers agree that under dry or drained conditions, cohesionless soils increase in stiffness with each loading cycle. Soil models that simulate the dynamic behaviors of soils are often coupled with the Masing criteria. Such models neglect the impact of stiffening during cyclic loading, leading to an underestimation in the shear modulus (G). This study investigates the stiffening behavior by conducting laboratory tests on three types of Danube sands using the Resonant Column-Torsional Simple Shear device (RC-TOSS). The increase in the dynamic shear modulus with an increasing number of cycles is substantial, especially for samples with low density. Sometimes, the dynamic shear modulus doubles when loaded at high stress levels for more than 50 cycles. A new model is introduced to simulate the stiffening behavior of dry sand when subjected to cyclic torsional loading. Modifications are proposed for the Ramberg–Osgood and Hardin–Drnevich models and for the Masing criteria to overcome the limitations that accompany these models due to the influence of stiffening caused by repetitive loading being ignored. This model can be implemented in finite element and finite difference software to solve dynamic geotechnical problems. Full article
(This article belongs to the Special Issue Computational Geodynamic, Geotechnics and Geomechanics)
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Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

1) Title: Analysis of rockburst damages in four blocks of Kiirunavaara mine, Sweden
Author lists:
Senzia Warema, Emilia Nordström, Erling Nordlund,Savka Dineva, Changping Yi
 
2) Title:Numerical analysis of the large-scale dynamic test of rock support at Kiirunavaara mine – Improved design
Author List:
Shirzadegan S., Warema S., Nordlund E., Lanaro F., Zhang P., Yi C and Bazargan M.
Abstract:
The numerical analysis results from an improved design of large-scale dynamic test of rock support is presented in this paper. The improved field test was designed based on the results obtained from field tests and the numerical analysis of the earlier tests (Tests 1 – 5) conducted at LKAB Kiirunavaara mine. The performed numerical analysis investigates how the improvements including minimizing the expansion of blasting gases into the burden, avoiding the complete damage of the burden, and creating sub-planar waves were achieved under the improved design of the test. Furthermore, the response of supported and unsupported excavations as well as the complex interaction of stress waves and rock support was numerically studied. The numerical analysis comprised of two stages (i) the explosion stage modelled with the finite element code LS-DYNA and (ii) the wave propagation stage which was modelled using UDEC with the results from LS-DYNA as input. The accuracy of the developed models was investigated by comparison of the two-dimensional and three-dimensional model results with UDEC and 3DEC methods. This is to obtain the data obtained from the field test. The numerical analysis results confirmed that the improved designed burden has assisted in reducing the areas of tensile yielding in the burden and as a result, the gas expansion and complete damage of the burden was avoided. The simulation results showed that the used support system (Swellex Mn 24 and reinforced shotcrete) has effectively limited the displacement of the test wall and prevented ejection during the dynamic loading. The combined numerical technique has shown its advantage when simulating blasting as well as interaction between waves and opening and it can thus be used as a tool for evaluating rock support performance.
 
3)Title: Numerical analysis of the large-scale dynamic tests of rock support at Kiirunavaara mine
Author List:
Shahin Shirzadegan, Warema S., Nordlund E., Zhang P., Yi C., and Mohsen Bazargan 
Abstract:
The numerical analysis of four dynamic large-scale field tests conducted at LKAB Kiirunavaara mine are presented in this paper. The aim was to numerically study the behaviour and response of the burden and the tested walls in field Tests 1, 2, 4 and 5. For this purpose, two numerical methods were combined, i.e.  the finite element code LS-DYNA and the distinct element code UDEC. The LS-DYNA was used to calculate the blast load, and the UDEC was used to propagate the calculated load in the model where the geological conditions of the test site and the installed rock support in the field tests were modelled. The model was calibrated by comparing the velocity and displacement calculated on the surface of the opening, and the zones yielded in tension were used to study the failure mechanism developed in the burden. The numerical models were able to mimic the behaviour of the jointed rock mass and the rock support fairly well. It is concluded that the number of major joint sets was the main reason to the difference between the failure development in Tests 1 and 2 and Tests 4 and 5. The numerical analysis of Tests 1 and 2 confirmed that the gas pressure in the vicinity of the test wall in those tests was minimum. In Tests 4 and 5, it was observed that, the generated fractures in the burden combined with the natural joint condition of the burden, increased the possibility for blocks to rotate and move within the burden. The complete burden damage in Tests 4 and 5 was concluded to be the be due to the ejection of rock blocks in the vicinity of the test wall upon the arrival of stress wave, and ejection of the remaining portion of the rock blocks in the burden by the gas expansion.
 
4. Title: Pressure, temperature and joint derivatives of crystalline rocks
Author List:
Mohsen Bazargan, Christoph Hieronymus, Bjarne Almqvist, Hem Bahadur Motra
Abstract:
Pressure and temperature system changes in the earth crust from surface to a deeper depth. These pressure and temperature changes can influence the physical properties of rocks. There are many studies on samples at elevated pressure, where the influence of open cracks, fractures, voids and pores are introduced. It is expected that applying confining pressure direct influence is on crack closer, this influence on dynamic properties of rocks above 200MPa is assumed linear. Inducing temperature can affect the dynamic properties of rock by reopening the pores, closed cracks, and expanding the grains.
 
 
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