Arabian Journal of Geosciences最新文献

Translational rockslides caused by toe excavation are one of the commonly seen geohazards in mountainous regions due to line traffic construction. Quantifying their failure extension length (FEL) and travel distance is of significant interest as well as huge challenges in landslide hazard assessment. In this paper, a simple criterion is proposed for predicting these two factors based on the principles of rigid body limit equilibrium and kinetic energy theorem. Further, the proposed criterion is validated against the field observations and numerical results with a practical case of the Xinjianan landslide, a medium-sized translational rockslide that occurred in 2013 in Nanchuan District, Chongqing. The findings indicate that a tiny discrepancy can be found in FEL between the field observations and the proposed criteria, while this discrepancy could be considerable in travel distance between different methods. However, the relative discrepancies all fall within 20%, deemed acceptable.

Nowadays new soil stabilization techniques are being sought to reduce the cost of road and highway construction, and therefore increase their lifetime. One of such techniques is the utilization of geosynthetic materials, particularly geotextiles. This paper specifically focuses on the application of non-woven geotextiles. Their selection is underpinned by their commendable mechanical and physical attributes, as well as their substantial potential for reinforcing and bolstering the bearing capacity of subsoils. In the pursuit of this investigation, two distinct soil types were sampled: one from the Missabougou district in Bamako, Mali, and the other from the Sariçam district in Adana, Turkey. Rigorous advanced laboratory tests, including particle size analysis, Atterberg limits, moisture content, specific gravity, compaction test, and California bearing ratio test were conducted. A total of 48 CBR experiments were carried out under unsoaked conditions, both with and without non-woven geotextiles. The geosynthetic materials were strategically placed at various depths within the CBR mold (H/5, 2H/5, 3H/5, 4H/5) in both single and multiple layers, with three compaction efforts applied to each sample. The findings revealed a significant enhancement in soil sample strength, particularly 100% compaction at H/5 for both Missabougou and Sariçam specimens. The CBR values for Missabougou soil were notably elevated from 12 to 76 with the presence of the geotextile. Similarly, the CBR outcome of Sariçam soil exhibited improvement from 45 to 75. The investigational results underscored a robust improvement in CBR values for the analyzed subsoils as a direct consequence of the effect of the reinforcement elements. The present study contributes to the pursuit of cost-effective soil stabilization techniques by highlighting the benefits of non-woven geotextiles. Using these materials strategically improves soil strength, emphasizing their potential application in highway and road construction, thus resulting in a longer lasting and more durable infrastructure.

The present research investigates the outcomes of inverting time domain induced polarization (TDIP) data, emphasizing the influence of parameters governing the IP response curve. In the subsurface, a resistive network follows relaxation patterns governed by the Cole-Cole model, where parameters like resistivity (ρ), chargeability (m), relaxation time (τ), and frequency exponent (c) shape the IP decay curve. Our exploration commences with exercises in forward modeling to understand how each parameter individually impacts the IP phenomenon. Subsequently, we introduce a tailored 1D forward modeling code dedicated to time domain IP, followed by a non-linear inversion process using the heat bath algorithm. These modeling equations are inherently non-linear, with the Cole-Cole parameters acting as independent variables. Using MATLAB, we implemented and rigorously validated this code using synthetic data and real field data gathered from the Sundarbans delta in West Bengal’s lower deltaic region. To delve deeper into subsurface dynamics, we created contour plots resembling pseudo sections for each Cole-Cole parameter, unveiling their subsurface variations. Notably, our results demonstrate a strong correlation with the geological features of the studied area.

Rural households of North 24 Parganas district, West Bengal (India), suffer twofold water-related problems, viz. supply of contaminated groundwater and waterlogging due to excessive rainfall for the last four decades. The present study deals with a mixed mode approach encompassing physical, socio-economic, and hydrogeological aspects to assess the water scarcity and feasibility of RWH among four blocks of North 24 Parganas, India. A hydrogeological cross-section (Fench Diagram) was developed to assess the potential of artificial recharge followed by the identification of artificial recharge sites with suitable structures using RS and GIS. Water quality parameters like TDS, ammonia-N, and chloride were found within the respective safe limit prescribed for drinking purposes in the water samples. The extent of water stress was assessed by a socio-economic survey conducted for rural households. Rural households expressed their willingness to adopt RWH subject to certain conditions. The LULC study showed a rapid increase (21.69%) in the built-up area during 2010–2020. The capacity of the storage tank was calculated as 6000 l for individual rural households. Sixty grams of disinfectant was suggested for the treatment of the harvested rainwater. The methods suggested would help local authorities execute successfully the RWH schemes in water-stressed areas.

Source rock is one of the major components of the hydrocarbon system. Understanding the maturity of the source rock and the patterns of the basin would have led to proposing a suitable site for drilling an exploratory well. Simulation of the hydrocarbon system is an indirect approach to an estimate of the exploration potential of a site. The current research purposes are to evaluate the maturation of the hydrocarbon fluids, trace the hydrocarbon migration pathway, and identify the possible source rock characteristics in the Garmsar area, Central Iran Basin. To this purpose, 1D and 2D modeling of the area have been carried out using PetroMod software to measure kerogen maturation and hydrocarbon generation and expel, as well as to stimulate the production of oil and gas from a source rock, migration pathway, and accumulation respectively. Geochemical characteristics of the source rocks were examined to estimate the hydrocarbon generation; the obtained data have demonstrated that there are relatively good quantities of organic matter in the source rocks of Qom Formation in Garmsar Block, and the organic matter is mainly type II and III. In general, source rock from the Garmsar Block spreads a satisfactory perspective for hydrocarbon generation. Furthermore, based on the 2D modeling, hydrocarbon accumulation begins in the C4 member of the Qom Formation and, eventually to the present, increases in anticlines at the central part of the study area in the F member of the Qom Formation.

In urban areas, shallow foundations are inevitably adjacent to each other. Moreover, the presence of thin, weak layers in these areas is not unanticipated. This study analyzes the combined impact of a thin, weak layer and the interaction of adjacent foundations on bearing capacity. Whereas previous research has separately explored the effects of weak layers and adjacent foundations. To attain the research objective, by utilizing the finite element method, the impact of various parameters, such as spacing between the foundations, the shear strength characteristics of a thin, weak layer, and the depth of this layer from the surface on the behavior of the adjacent shallow foundations studied. The foundation bed and thin-weak layer are assumed to be sandy soil. The analysis result indicates that the thin and weak layers reduce the bearing capacity of the shallow foundations, which is related to the shear strength parameters of the weak layer. Nevertheless, the placement of adjacent foundations at a short distance from each other reduces the negative impact of the existence of the thin, weak layer. This impact depends on the shear strength parameters, the depth of the weak layer, and the distance between the foundations. Compared to a single foundation, interfering footings can increase between 6 and 50% in the bearing capacity. The depth of the impact of the weak layer on the bearing capacity will also be a function of the distance between the adjacent foundations.

This short communication explores the urban geology sub-field, which emerges as a crucial discipline to address the dynamic interaction between human activities, geological processes, and environmental sustainability. It aims to guide land use planning, assess and mitigate the impacts of urbanization on natural resources, evaluate geological hazards, address geoenvironmental problems, and enhance public awareness. The correspondence also touched upon urban geochemistry, a relatively nascent interdisciplinary sub-field, elucidating its role in studying trace element characteristics, human activities’ impacts on the environmental quality, and the influence on biogeochemical cycles. Despite its significance, urban geology faces underappreciation and challenges, particularly in African megacities. Inadequate funding, data collection difficulties, and a lack of awareness hinder its promotion. Therefore, we advocate for increasing the collaboration between academic institutions, research centers, and governmental authorities to overcome these barriers and promote multidisciplinary research projects for a holistic understanding of the complexities of the urban environments.

Geological, mineralogical, and physicochemical information were used to analyze the possible industrial applications and general observations of the Ammacio kaolin occurrence, which is located southwest of the Central Main Ethiopian Rift. The principal lithologic units present in the study area are basalt, unwelded tuff, and Quaternary sediment. The parent rock for the kaolin is the unwelded tuff unit. The petrographic study of the parent rock indicates the presence of plagioclase, alkali-feldspar, and quartz phenocrysts in a fine-glassy groundmass. X-ray diffraction, Fourier transforms infrared, and scanning electron microscopy analyses suggest that the kaolin samples are made up mostly of kaolinite and quartz minerals, with traces of halloysite and feldspar. The distributions of major and selective trace elements in the parent rocks and the kaolin samples, along with the higher chemical index of alteration (CIA = 84.4%) and chemical index of weathering (CIW = 92.4%), indicate that the kaolin is formed by intense chemical weathering of the unwelded tuff. The overall mineralogical and physicochemical findings suggest that Ammacio kaolin may be employed in a variety of sectors, including in paper coating, as a filler (in the paper, rubber, plastic, and paint industries), ceramics, agriculture, pottery, brick, soap and detergent, cosmetics, fiberglass, pharmaceutical, Portland cement, and synthetic zeolites productions industries.

This paper presents a comprehensive investigation into pore pressure prediction methodologies, specifically addressing challenges in the upper zones of a field in southwestern Iran characterized by intricate geological complexities. Our analysis centers on the application of the drilling exponent (D-exponent) methodology, utilizing drilling parameters for accurate pore pressure estimation. Three methodologies are scrutinized: a section-specific approach, a site-specific analysis establishing unique normal compaction trend lines, and a novel method refining the normal compaction trend line mathematically. The Zamora method stands out as superior, especially in geologically complex regions like the Gachsaran formation, where overburden pressure may not be the primary stress. Implementing the Zamora method yields a substantial reduction in mean absolute percentage error (MAPE), enhancing pore pressure prediction accuracy by up to 9%. Additionally, a newly proposed method enhances accuracy by 7%. These findings underscore the importance of customizing pore pressure prediction techniques to the distinct geological conditions of specific regions. The outcomes not only advance our understanding of pore pressure prediction but also offer practical guidance for similar geological settings.

This research work studies a problem associated with an axisymmetric torsion of an orthotropic layer by a circular rigid disc at the midplane. The orthotropic layer is sandwiched by two identical orthotropic half-spaces with two interfaced cracks. The layer and half-spaces are dissimilar in nature. The mixed boundary value problem is reduced to a system of dual integral equations by Hankel transformation, which are converted to Fredholm integral equations of the second kind. The integral equations are solved numerically by the quadrature rule. The stress intensity factors for crack and disc have been derived and are presented graphically for different thicknesses of orthotropic layer.