Hem Bahadur Motra
@hem.motra@ifg.uni-kiel.de
Lecturer, Geomechanics, Rock Mecahnics and Geotechnical Engineering
University of Kiel
I currently work as a academic staff at the institute of geoscience Kiel University, Germany. My research is mainly driven by my curiosity about the reliable engineering computing, structural reliability, risk and hazard analysis, quality evaluation of models, geostatistics, probabilistic methods, physical processes control rock material behaviour in the subsurface, along with the direct relevance of this field to socially relevant issues, such as mining, nuclear disposal, geotechnical engineering, geo-energy and oil production.
I am a leading academic and researcher in geomechanics, rock mechanics, mining geomechanics, and engineering geology, with a strong international profile in both teaching and research. I have published over 50 peer-reviewed journal papers and hold an h-index of 15, reflecting my substantial impact on the field. I have taught and supervised B.Sc., M.Sc., and PhD theses across core geotechnical subjects.
EDUCATION
PhD in Geotechnical Engineering
RESEARCH, TEACHING, or OTHER INTERESTS
Geotechnical Engineering and Engineering Geology, Civil and Structural Engineering, Safety, Risk, Reliability and Quality, Renewable Energy, Sustainability and the Environment
FUTURE PROJECTS
How Important is Compositional Layering within the Earth? Testing the Hypothesis using Seismic Anisotropy
Seismological observations indicate that large regions within Earth show directionally dependent seismic wave speeds. Such seismic anisotropy is a unique and invaluable indicator for geodynamic processes, structure and rheology of the Earth. However, a challenge in using anisotropy is that it arises from different sources, leading to non-unique interpretations of the geodynamic process that give rise to anisotropy. Intrinsic anisotropy originates from single crystals, or aggregates of oriented crystals, which is known as crystallographic preferred orientation (CPO). It is an important source for anisotropy in the deeper parts of the crust, mantle and core. Extrinsic, or apparent, anisotropy arises from geometrical effects such as layering of rocks, and oriented crack and fluid networks. In this project, particular focus is placed on testing the hypothesis that mineral compositional banding is an important contributor to seismic anisotropy throughout the interior of Earth, which has not
Applications Invited
Scopus Publications
Scopus Publications
Mohammad Nadi, Amin Azhari, Hajar Share Isfahani, Hem B. Motra, Mahmoud Hefny, Abbas Salati, and Mohsen Bazargan
Springer Science and Business Media LLC
Abstract The safe containment of hazardous waste requires landfill liner materials with both effective radiation shielding and strong hydro-mechanical performance. This study investigates the potential of a bentonite-goethite mixture as a novel material for hazardous waste landfill liners. The study examines the radiation shielding of the mixtures, represented by the linear attenuation coefficient, through experimental (Na (Tl) spectrometer detector), numerical (MCNP code), and reference database (XCOM and PHY-X) approaches. Moreover, the hydraulic permeability and mechanical properties are evaluated experimentally. For this, the varying proportions of goethite from 10 to 50% were examined. The results show an increase of up to 20, 24, and 28 percent in the linear attenuation coefficient at gamma ray energies of Cs $$^{137}$$ (661.6 keV) and Co $$^{60}$$ (1173.2 and 1332.5 keV). Higher goethite percentages, correlating with density variations and enhancing radiation shielding effectiveness. Numerical and reference database results align closely with experimental findings, suggesting their utility for assessing other mixtures. The direct shear test reveals that with an increase of goethite proportion to 50 percent, the cohesion is reduced to half and the friction angle is inclined twice the pure bentonite values, attributed to bentonite reduction and goethite roughness. Unconfined compressive strength trends show 20% improvement at specific mixture composition with 30% goethite, while hydraulic conductivity inclines with goethite content to $$\\mathrm { 8.8\\times 10^{-10}}$$ m/s. In this study the bentonite-goethite mixture illustrates improving radiation shielding and maintaining hydro-mechanical properties for landfill liners. This may offer a sustainable alternative using waste materials from mineral processing, contributing to waste management and environmental sustainability.
Hem Bahadur Motra
MDPI AG
Marine geotechnical engineering is undergoing a rapid transformation driven by the increasing global demand for offshore energy, resilient coastal infrastructure, and sustainable seabed utilization [...]
Farshad Sadeghpour, Hem Bahadur Motra, Chinmay Sethi, Sandra Wind, Bodhisatwa Hazra, Ghasem Aghli, and Mehdi Ostadhassan
Elsevier BV
Nooshin Senemarian Isfahani, Amin Azhari, Hem B. Motra, Hamid Hashemalhoseini, Mohammadreza Hajian Hosseinabadi, Alireza Baghbanan, and Mohsen Bazargan
MDPI AG
A systematic sensitivity analysis using three-dimensional discrete element models with discrete fracture networks (DEM-DFN) was conducted to evaluate underground excavation support in jointed rock masses at the CLAB2 site in Southeastern Sweden. The site features a joint network comprising six distinct joint sets, each with unique geometrical properties. The study examined 10 DFNs and 19 rock bolt patterns, both conventional and unconventional. It covered 200 scenarios, including 10 unsupported and 190 supported cases. Technical and economic criteria for stability were assessed for each support system. The results indicated that increasing rock bolt length enhances stability up to a certain point. However, multi-length rock bolt patterns with similar consumption can yield significantly different stability outcomes. Notably, the arrangement and properties of rock bolts are crucial for stability, particularly in blocks between bolting sections. These blocks remain interlocked in unsupported areas due to the induced pressure from supported sections. Although equal-length rock bolt patterns are commonly used, the analysis revealed that triple-length rock bolts (3, 6, and 9 m) provided the most effective support across all ten DFN scenarios.
Ghasem Aghli, Reza Gholami, Mohammad Reza Saberi, Mohammad Nikbin, Tahura Ahsani, Hem Bahadur Motra, and Mehdi Ostadhassan
American Geophysical Union (AGU)
AbstractIn this research, we explored how various fracture parameters could influence the elastic response of heterogeneous carbonates. Herein, 16 core plugs from a fractured carbonate formation are subjected to a comprehensive analysis including CT‐scanning, optical and electron microscopy, and XRD analysis to identify and characterize open fractures and their corresponding features. Subsequently, these samples underwent hydrostatic compression under reservoir conditions, during which ultrasonic wave velocities and strain were continuously measured while confining pressure was gradually increased to 65 MPa, pore pressure remained constant at zero, and temperature at 90°C. Our findings revealed that the presence of open fractures would cause a reduction in both compressional and shear wave velocities while causing strain variations. The extent of these changes, however, is notably influenced by fracture parameters, particularly connectivity, dip, and aperture. Furthermore, the study showed that the influence of stylolites and solution seams is the secondary influential factor, primarily impacting the P‐wave and increasing the strain. This research suggests that the impact of structural features, especially fractures, supersedes the role of porosity percentage in controlling the elastic properties of carbonate rocks. Furthermore, it was concluded that when fractures form a network, they exert a more pronounced impact on the elastic response compared to their isolated existence. This observation confirms that detection of fractures should be supplemented with a detailed assessment of their parameters. Collectively, this study provides valuable insights into how distinct fracture parameters would improve our interpretation of carbonate reservoirs elastic response, with a particular focus on wave velocities.
Chinmay Sethi, Hem Bahadur Motra, Bodhisatwa Hazra, and Mehdi Ostadhassan
Elsevier BV
Bodhisatwa Hazra, Hem Bahadur Motra, James C. Hower, Maria Mastalerz, Chinmay Sethi, and Harold Schobert
Elsevier BV
Bo Liu, Aydin Larestani, Kouqi Liu, Yifei Gao, Hem B. Motra, Abdolhossein Hemmati-Sarapardeh, and Mehdi Ostadhassan
Elsevier BV
Ghasem Aghli, Hem Bahadur Motra, Mohammad Reza Saberi, Mohammad Nikbin, and Mehdi Ostadhassan
Springer Science and Business Media LLC
Abstract Open fractures are an important contributor to reservoir quality in carbonate formations. Herein, their development and relevant parameters are controlled by various factors, among which lithology is considered the most critical. With this in mind, we investigated differences in open-fracture parameters between dolomite and calcite intervals to understand how lithology influences fracturing. To this end, several wells within a sequence of dolomitic and calcitic intervals from the major oil producing Asmari Formation (southwest Iran) which is a major fractured reservoir were chosen. Detailed petrographic and petrophysical analyses were carried out to characterize the fracture intervals in this reservoir. Then, fracture parameters such as density, aperture, porosity, and dip as well as reservoir heterogeneity were quantified using high-quality electrical image logs and core data. Finally, fracture parameters were compared between the two lithologies to delineate their variations. Furthermore, sonic waveforms and well-test data from the selected wells confirmed the presence of fractures and their estimated parameters. Our results indicate that all dolomites in this reservoir are diagenetic and range from fine- to coarse-crystalline. Image logs confirmed that all detected fractures are structural (due to folding and faulting) and show larger apertures and better connectivity in the dolomite intervals, particularly in the coarser sections, than in calcites. Moreover, open fractures with large apertures appear to be the main source of heterogeneity within the dolomite intervals. Therefore, crystal size and structural features were identified as two additional governing factors in fracture development. This enhanced fracture network was distinguished by fluctuations in sonic waveforms within the coarser dolomite intervals (due to a better fracture network). Finally, the role of effective fracture parameters on reservoir heterogeneity is discussed. These findings provide valuable insights into fracture characterization in heterogeneous carbonate systems and can support more accurate reservoir modeling and improved development strategies in similar fractured reservoirs worldwide.
Fabio Trippetta, Roberta Ruggieri, and Hem B. Motra
Elsevier BV
Ghasem Aghli, Babak Aminshahidy, Hem Bahadur Motra, Ardavan Darkhal, Farshad Sadeghpour, and Mehdi Ostadhassan
Elsevier BV
Farshad Sadeghpour, Ardavan Darkhal, Yifei Gao, Hem B. Motra, Ghasem Aghli, and Mehdi Ostadhassan
Elsevier BV
R. Punturo, S. Mineo, H.B. Motra, G. Lanzafame, V. Indelicato, G. Pappalardo, and R. Cirrincione
Elsevier BV
Chinmay Sethi, Bodhisatwa Hazra, Mehdi Ostadhassan, Hem Bahadur Motra, Arpan Dutta, J.K. Pandey, and Santosh Kumar
Elsevier BV
Chao Wang, Bo Liu, Mohammad-Reza Mohammadi, Li Fu, Elham Fattahi, Hem Bahadur Motra, Bodhisatwa Hazra, Abdolhossein Hemmati-Sarapardeh, and Mehdi Ostadhassan
Elsevier BV
Henok Hailemariam, Nils Blume, Hem B. Motra, and Frank Wuttke
Informa UK Limited
Bo Liu, Mohammad-Reza Mohammadi, Zhongliang Ma, Longhui Bai, Liu Wang, Zhigang Wen, Yan Liu, Hem Bahadur Morta, Abdolhossein Hemmati-Sarapardeh, and Mehdi Ostadhassan
Elsevier BV
Kouqi Liu, Sirous Hosseinzadeh, Majid Safaei-Farouji, Bo Liu, Hem B. Morta, and Mehdi Ostadhassan
Elsevier BV
Kouqi Liu, Majid Safaei-Farouji, Yifei Gao, Thomas Gentzis, Bo Liu, Hem B. Morta, and Mehdi Ostadhassan
Elsevier BV
Mohammad Hosein Khosravi, Mahdi Kheirollahi, Bo Liu, Thomas Gentzis, Kouqi Liu, Hem B. Morta, and Mehdi Ostadhassan
Elsevier BV
Mohsen Bazargan, Bjarne S. G. Almqvist, Hem Bahadur Motra, Pooyan Broumand, Tobias Schmiedel, and Christoph F. Hieronymus
MDPI AG
Laboratory-based elastic wave measurements are commonly used to quantify the seismic properties of Earth’s crust and upper mantle. Different types of laboratory apparatuses are available for such measurements, simulating seismic properties at different pressure and temperature. To complement such laboratory measurements, we present a numerical toolbox to investigate the seismic properties of rock samples. The numerical model is benchmarked against experimental results from a multi-anvil apparatus, using measurements of a stainless steel calibration standard. Measured values of the mean compressional- and shear-wave velocities at room conditions of the steel block were 6.03 km/s and 3.26 km/s, respectively. Calculated numerical results predicted 6.12 km/s and 3.30 km/s for compressional and shear-wave velocities. Subsequently, we measured Vp and Vs up to 600 MPa hydrostatic confining pressure and 600 °C. These measurements, at pressure and temperature, were then used as the basis to predict numerical wave speeds. There is, in general, good agreement between measurement and predicted numerical results. The numerical method presented in this study serves as a flexible toolbox, allowing for the easy setup of different model geometries and composite materials.
Sascha Zertani, Jan Pleuger, Hem B. Motra, and Timm John
Elsevier BV
Mohsen Bazargan, Hem Bahadur Motra, Bjarne Almqvist, Sandra Piazolo, and Christoph Hieronymus
Elsevier BV