{"title":"Calcite e-twins as a tectonic indicator, paleo stress pattern and structural evolution of the Zagros hinterland, SE Iran","authors":"Hamed Dorzadeh, Shahram Shafieibafti, Saeede Keshavarz, Jafar Omrani, Ahmad Rashidi, Majid Nemati, Reza Derakhshani","doi":"10.3389/feart.2024.1445918","DOIUrl":"https://doi.org/10.3389/feart.2024.1445918","url":null,"abstract":"Through the examination of calcite twins, this research outlines the tectonic development and paleo stress patterns of the Paleozoic Routshon complex situated in the southeastern segment of the Sanandaj–Sirjan zone, a hinterland region of the Zagros orogeny in southeastern Iran. The study of orogenic phase indicates that the deformation event affecting the southern sector of the Sanandaj-Sirjan zone aligns with the Cimmerian orogenic phase of the Late Triassic period. A variety of structural features at both map and outcrop scales highlight the importance of slip partitioning in the structural evolution of this region, driven by inclined transpression. Observations suggest that the deformation related to contractional components includes steeply to moderately plunging folds, dip-slip domain deformation primarily involving thrusts, and ongoing deformation by strike-slip component motion, which results in thrust-related ductile shear zones. The analysis of calcite c-axis fabrics from mylonite samples obtained from these shear zones indicates a low-temperature monoclinic pattern of non-coaxial deformation. This deformation type underscores the impact of the strike-slip component in the development of progressive simple shear within thrust-related shear zones in this segment of the Sanandaj-Sirjan zone. Dynamic analysis of c-axis fabric data reveals a NE-SW orientation for the principal compressive axes (σ1) in this area. This direction, corroborated by additional data such as fault surface, GPS, and earthquake focal mechanism data, confirms that the orientation of the compressive axes (σ1) has remained consistent from the Late Triassic to the present.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"2 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research on the impact of FDI and environmental regulation on the industrial structure upgrading in the Yellow River Basin","authors":"Jinxiu Yu","doi":"10.3389/feart.2024.1379870","DOIUrl":"https://doi.org/10.3389/feart.2024.1379870","url":null,"abstract":"Introductions: Since the reform and opening up, the inflow of foreign direct investment (FDI) has provided a steady stream of capital, technology, talent and other resources for the development of the Yellow River basin, while caused problems such as environmental pollution, ecological fragility and industrial structure upgrading difficulties to some extent. Environmental regulation is a pivotal initiative to achieve mutual harmony between ecological environment and economic development, which could enhance the quality of the introduction of FDI and accelerate the green transformation of the development mode.Methods: Based on urban panel data from 2006–2019, this study empirically examined the impact of FDI and environmental regulation on industrial structure upgrading in the Yellow River Basin. Moreover, taking environmental regulation as a threshold variable, a panel threshold model was established to further explore the role of environmental regulation in the impact of FDI on industrial structure upgrading in the Yellow River Basin.Results: (1) The relationship between FDI and industrial structure upgrading in the Yellow River Basin is not a simple linear relationship, but an inverted “U”-shaped relationship that rises first and then falls, and the results of this inverted “U”-shaped relationship are still robust after replacing key indicators. (2) The environmental regulation policy has a driving effect on the upgrading of industrial structure in the Yellow River Basin. (3) Environmental regulation has a positive role in the influence of FDI on the industrial structure upgrading in the Yellow River basin, and the positive role increases gradually as the intensity of environmental regulation increases moderately, but if the intensity of environmental regulation is too high, it will have a negative impact on the upgrading of industrial structure in the Yellow River basin to some extent.Discussion: In the future, policymakers should make reasonable and effective use of FDI and improve the quality of FDI; reasonably formulate environmental regulation policies; coordinate the intensity of FDI and environmental regulation; thus, bring into play the promotion effect of FDI and environmental regulation on industrial structure upgrading, and then realize the win-win of ecological protection and high-quality economic development in the Yellow River Basin.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"57 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anupam Yadav, Saeed Hameed Aldulaimi, Farag M. A. Altalbawy, Praveen K. N. Raja, M. Janaki Ramudu, Nizomiddin Juraev, Hameed Hassan Khalaf, Bassam Farman Bassam, Nada Qasim Mohammed, Dunya Jameel Kassid, Ahmed Elawady, Mohammad Sina
{"title":"Prediction of saturation exponent for subsurface oil and gas reservoirs using soft computing methods","authors":"Anupam Yadav, Saeed Hameed Aldulaimi, Farag M. A. Altalbawy, Praveen K. N. Raja, M. Janaki Ramudu, Nizomiddin Juraev, Hameed Hassan Khalaf, Bassam Farman Bassam, Nada Qasim Mohammed, Dunya Jameel Kassid, Ahmed Elawady, Mohammad Sina","doi":"10.3389/feart.2024.1434820","DOIUrl":"https://doi.org/10.3389/feart.2024.1434820","url":null,"abstract":"The most widely used equation to calculate water saturation or suitable shaly water saturation in clean or shaly formation, respectively, is the modified Archie formula. The quality of Archie parameters including saturation exponent affects the preciseness of water saturation, and thus estimated oil and gas in place. Therefore, estimating the saturation exponent by the soft computation methods deems to be necessary. In this study, intelligent models such as multilayer perceptron neural network, least squares support vector machine, radial basis function neural network, and adaptive neuro-fuzzy inference system are developed to predict saturation exponent in terms of petrophysical data including porosity, absolute permeability, water saturation, true resistivity, and resistivity index by utilizing a databank for middle east oil and gas reservoirs. The introduced models are optimized using particle swarm optimization, genetic algorithm, and levenberg marquardt techniques. Graphical and statistical methods are used to demonstrate the capability of the constructed models. Based on the statistical indexes obtained for each model, it is found that radial basis function neural network, multilayer perceptron neural network, and least squares support vector machine are the most robust models as they possess the smallest mean squared error, root mean squared error and average absolute relative error as well as highest coefficient of determination. Moreover, the sensitivity analysis indicates that water saturation has the most effect and porosity has the least effect on the saturation exponent. The developed models are simple-to-use and time-consuming tools to predict saturation exponent without needing laboratory methods which are tedious and arduous.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"10 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The influence range of the biogas desaturation method for mitigating sand liquefaction","authors":"Erxing Peng, Dandan Li, Xiaoying Hu, Binbin He, Haiming Dang, Youqian Liu","doi":"10.3389/feart.2024.1433507","DOIUrl":"https://doi.org/10.3389/feart.2024.1433507","url":null,"abstract":"To clarify the influence range and saturation distribution after the biogas desaturation method is applied, a three-dimensional model is established with TOUGH2 software to analyze the effect of construction parameters such as grouting volume, grouting rate, grouting depth, nitrogen source concentration, and soil porosity. After that, the sensitivity of the parameters on the influence range is determined. The grouting volume and soil porosity are the most sensitive to the lateral and vertical influence range, respectively. This study provides a basis for the engineering practice of treating liquefiable subgrade by the biogas desaturation method.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"72 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengyan Du, Jingong Cai, Huidong Li, Xuejun Zhang, Juan Wang, Liping Yang, Yanzhong Zhen
{"title":"Quantification of organic and inorganic hydrogen in mudstones: a novel approach using the difference between organic-rich and organic-free mudstones during pyrolysis process","authors":"Pengyan Du, Jingong Cai, Huidong Li, Xuejun Zhang, Juan Wang, Liping Yang, Yanzhong Zhen","doi":"10.3389/feart.2024.1421404","DOIUrl":"https://doi.org/10.3389/feart.2024.1421404","url":null,"abstract":"Whether mudstone is rich in or free of organic matter has a great influence on the occurrence of water. Comparing different types of water in organic-rich and organic-free mudstones is helpful for further understanding the role of water in hydrocarbon generation. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) combined with mass spectrometry (MS) afford the opportunity to identify the mass change, reactions and products of the sample in a real-time monitored heating process. This study compared the pyrolysis characteristics of an organic-rich mudstone (CN1) and an organic-free mudstone (CW1) by using the TGA/DTA-MS method to estimate the content of different types of H<jats:sub>2</jats:sub>O and CO<jats:sub>2</jats:sub> in organic-rich mudstones. The results show that the mass changes in CN1 and CW1 can be divided into the three thermogravimetric (TG) stages of 0°C–200°C, 200°C–650°C, and 650°C–900°C, while the peak temperatures of H<jats:sub>2</jats:sub>O and CO<jats:sub>2</jats:sub> obtained through MS are different for CN1 and CW1. The differences in mineral components and organic matter between CN1 and CW1 suggest that the MS peaks of H<jats:sub>2</jats:sub>O and CO<jats:sub>2</jats:sub> in CW1 are mainly influenced by clay and carbonate minerals, and that those of CN1 are also influenced by organic matter. In addition, quantification equations for CO<jats:sub>2</jats:sub> and H<jats:sub>2</jats:sub>O contents from both the organic and inorganic origin of the organic-rich mudstone can be established by using the MS peak area of CO<jats:sub>2</jats:sub> and H<jats:sub>2</jats:sub>O, mass loss in TGA and the mineral composition of the organic-free mudstone. This work provides useful insights for further understanding the hydrocarbon generation mechanism, as well as quantifying different types of water in organic-rich mudstones.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"56 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingqiang Sheng, Qixin Zhu, Faming Huang, Chun Zou, Yang Gao, Xinxin Liu
{"title":"Study on the formation and dewatering process of the surface filter cake of geotextile on the lateral boundary of geotextile tubes under constant flow grouting","authors":"Mingqiang Sheng, Qixin Zhu, Faming Huang, Chun Zou, Yang Gao, Xinxin Liu","doi":"10.3389/feart.2024.1427659","DOIUrl":"https://doi.org/10.3389/feart.2024.1427659","url":null,"abstract":"In this article, physical model test and numerical simulation are used to study the formation of filter cake and the filtration performance of the geotextile on the lateral boundary of the ultra-fine tailings grouting geotextile tubes from macro and micro levels. At the macro level, the effects of different grouting flow rates and tailings slurry mass concentrations on the surface filter cake formation and the dehydration performance of geotextile on the lateral boundary of the geotextile tubes were analyzed. At the micro level, the use of CFD-DEM method for fluid and particle of two-way coupling numerical simulation research, lateral drainage boundary of superfine tailings in tubes filter cake forming process is analyzed. The research shows that the increase of grouting flow rates and tailings slurry mass concentrations will make the thickness of filter cake great and the structure more compact, which will lead to more serious silting of the surface layer of geotextile and greatly reduce the dehydration performance; The numerical simulation results regularity is consistent with the results regularity of physical model test on the formation of filter cake on geotextile surface of geotextile tubes: the larger the slurry inlet speed and particles concentrations, the more complete the formation of filter cake on geotextile surface, the denser the cake structure, and the less tailings loss. By studying the effects of grouting flow rates and slurry mass concentrations on the surface filter cake formation and tubes dehydration, this article aims to find suitable slurry filling construction conditions and explore the main influencing factors caused by dehydration and consolidation of ultra-fine tailings grouting geotextile tubes, so as to provide some help for the subsequent flocculating of ultra-fine tailings to solve the problem of surface drying and internal wetting of geotextile tubes.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"96 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic evolution of amplitude and position of geomagnetic secular acceleration pulses since 2000","authors":"Chunhua Bai, Guoming Gao, Limin Wen, Guofa Kang","doi":"10.3389/feart.2024.1383149","DOIUrl":"https://doi.org/10.3389/feart.2024.1383149","url":null,"abstract":"Recent studies on the behavior of geomagnetic secular acceleration (SA) pulses have provided a basis for understanding the dynamic processes in the Earth’s core. This analysis statistically evaluates the evolution of the SA pulse amplitude and position since 2000 by computing the three-year difference in SA with the CHAOS-7 geomagnetic field model (CHAOS-7.17 release). Furthermore, the study explores the correlation between the acceleration pulse amplitude and geomagnetic jerks and the dynamic processes of alternating variation and polarity reversal of pulse patches over time. Research findings indicate that the variation in pulse amplitude at the Core Mantle Boundary (CMB) closely resembles that observed at the Earth’s surface, with an average period of 3.2 years. The timing of peak pulse amplitude aligns with that of the geomagnetic jerk, suggesting its potential utility as a novel indicator for detecting geomagnetic jerk events. The acceleration pulses are the strongest near the equator (2°N) and more robust in the high-latitude region (68°S) of the Southern Hemisphere, indicating that the variation is more dramatic in the Southern Hemisphere. The acceleration pulses fluctuate unevenly in the west-east direction, with characteristics of local variation. In the Western Hemisphere, the pulse patches are distributed near the equator, exhibiting an evident westward drifting mode. The positive and negative patches alternate in time, displaying a polarity reversal in the west-east direction, with an average interval of approximately 32°. These characteristics can be attributed to the rapid magnetic field fluctuations disclosed by the model of stratification at the top of the Earth’s core. In the Eastern Hemisphere, the pulses are weaker between 10°E and 60°E, with the most active pulses occurring around 80°E to 105°E and near 150°E. The pulse patches exhibit a broader distribution in the north-south direction, with relatively strong patches still occurring near 40°N and 40°S. These local variation characteristics match the actual cases of zonal flows and geostrophic Alfvén waves in the Earth’s core.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"21 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianbiao Wu, Runsheng Han, Yan Zhang, Peng Wu, Hongsheng Gong, Lei Wang, Gong Cheng, Xiaodong Li, Yixuan Yang, Yaya Mi
{"title":"Porosity–permeability characteristics and mineralization–alteration zones of the Maoping germanium-rich lead–zinc deposit in SW China","authors":"Jianbiao Wu, Runsheng Han, Yan Zhang, Peng Wu, Hongsheng Gong, Lei Wang, Gong Cheng, Xiaodong Li, Yixuan Yang, Yaya Mi","doi":"10.3389/feart.2024.1347243","DOIUrl":"https://doi.org/10.3389/feart.2024.1347243","url":null,"abstract":"The Maoping superlarge germanium-rich lead–zinc deposit is a typical nonmagmatic hydrothermal deposit that is structurally controlled in the Sichuan–Yunnan–Guizhou lead–zinc polymetallic metallogenic area. The orebodies are distributed in several formations. This paper is based on large-scale alteration mapping combined with porosity and permeability measurements. We delineated the mineralization–alteration zones of different ore-bearing formations, explored the geological significance of porosity and permeability, and proposed prospecting directions. The research results indicate that during the mineralization period, the ore-forming metal fluids migrated from the deep part of the SSW region to the shallow part of the NNE region along the ore-guiding structure (Maoping Fault). Through the ore distribution structure, depressurization boiling occurred in the open space of the NE-trending interlayered sinistral compressive–torsional faults in several ore-bearing formations, resulting in fluid precipitation and the formation of different brecciated hot-melt dolomite lead–zinc mineralization zones. From the orebody to the wallrock, the C<jats:sub>2</jats:sub>w Formation and D<jats:sub>3</jats:sub>zg Formation are divided into four different mineralization–alteration zones. Tectonic activity affects the properties, migration, and precipitation of fluids, thereby controlling the alteration characteristics generated during fluid migration and thus changing the porosity and permeability. The porosity and permeability of strata on the NW flank of the anticline are greater than those of strata on the SE flank. On the NW flank, the greater the degree of mineralization–alteration is, the greater the porosity and permeability are, and the porosity of the orebody is lower than that during dolomitization. Finally, we believe that the NW flank of the anticline is an important area for prospecting. The pyrite + striped altered dolomite zone (Zones II–III) in the C<jats:sub>2</jats:sub>w limestone and the pyrite + strong dolomite zone (Zones II–III) in the D<jats:sub>3</jats:sub>zg dolomite are important prospecting indicators.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"24 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Gao, Lin Jiang, Weiyan Chen, Fujie Jiang, Hongkui Dong, Wen Zhao, Changyu Dong, Yingqi Feng
{"title":"Provenance of cretaceous sediments in the West Kunlun piedmont belt and implications for tectonic evolutionary events","authors":"Yang Gao, Lin Jiang, Weiyan Chen, Fujie Jiang, Hongkui Dong, Wen Zhao, Changyu Dong, Yingqi Feng","doi":"10.3389/feart.2024.1431866","DOIUrl":"https://doi.org/10.3389/feart.2024.1431866","url":null,"abstract":"The West Kunlun orogenic belt located in the northwestern margin of the Qinghai-Tibet Plateau is an important record of the formation and northward extension of the plateau, but the current research mainly focuses on the tectonic activities of the Cenozoic era, and there is still considerable controversy regarding the formation and evolutionary history of pre-Cenozoic orogenic belts. This study focuses on Cretaceous sandstone samples from the Kedong region in the piedmont belt of the West Kunlun orogenic belt. U-Pb geochronological analysis was performed on 200 detrital zircon grains from the core samples. Combined with stratigraphic data and previous research, the main provenance direction was investigated to constrain the tectonic evolutionary history of the orogenic belt’s peripheral regions. The results show that the detrital zircons are aged from 290 to 208 Ma, 520–310 Ma, 810–580 Ma, 1,400–880 Ma and 2,548–1,730 Ma, reflecting the complexity of provenance in this area. Based on a comprehensive analysis of the characteristics of igneous rocks, zircon age composition and stratigraphic conditions in potential source areas, it is concluded that the primary source regions include the East Kunlun orogenic belt and the North and South Kunlun terranes, with a low likelihood of contributions from within the Tarim Basin. The evolution of the West Kunlun orogenic belt can generally be divided into two opening and two closing phases. The detrital zircon ages predominantly exhibit two peak values at 259 Ma and 459 Ma, respectively representing the ages of transition from oceanic crust subduction to continent-continent collision for the Paleo-Tethys Ocean and the Proto-Tethys Ocean. Additionally, there is a temporal gap between the evolution of the Proto-Tethys Ocean and the Paleo-Tethys Ocean. The Triassic period marks a transitional phase in tectonic evolution, shifting into an intracontinental evolutionary stage. This study provides new geochronological evidence for the early developmental history of the West Kunlun orogenic belt.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"37 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Di Sun, Zhigang Tao, Hong Yang, Haoche Shui, Xiaotian Lei, Fengnian Wang, Shusen Huo, Hang Shu, Weitong Xia, Zhaoxi Wang, Manchao He
{"title":"Analytical solution for mechanical behavior characterization of sandy dolomite tunneling","authors":"Di Sun, Zhigang Tao, Hong Yang, Haoche Shui, Xiaotian Lei, Fengnian Wang, Shusen Huo, Hang Shu, Weitong Xia, Zhaoxi Wang, Manchao He","doi":"10.3389/feart.2024.1384143","DOIUrl":"https://doi.org/10.3389/feart.2024.1384143","url":null,"abstract":"Tunneling in sandy dolomite strata often faces hazards such as collapse, water inrush, and water–sand inrush, seriously threatening the safety of tunnel construction. There are currently limited studies on the mechanical behaviors of sandy dolomite tunnels. In view of this, an analytical solution for tunneling in sandy dolomite strata is derived in this study, and then parametric analysis is performed to analyze the mechanical response of rock mass in sandy dolomite tunnels. The results demonstrate five tunnel sidewall stress scenarios according to the different lateral pressure coefficients (<jats:italic>λ</jats:italic>). Varying λ values impact stress distribution and tunnel stability, with extreme values posing risks of instability. Tunnel safety is greatly reduced when rock stress approaches the plastic limit. At different internal friction angles, cohesion, and initial rock stresses, radial stress decreases gradually as the radius increases. The stress values under different conditions tend to be similar, while the effects of internal friction angle, cohesion, and initial rock stress on stress in the elastic zone decrease with increasing distance from the center of the tunnel. Under different internal friction angles and cohesion, the plastic zone radius increases with increasing distance from the excavation surface, and a larger internal friction angle and cohesion lead to an increase in stress. The stress and cohesion of a rock mass significantly affect the plastic zone radius, and an increase in tunnel excavation radius also leads to an increase in the radius of plastic zone. These findings provide a reference and insight for similar geotechnical engineering practices in the future.","PeriodicalId":12359,"journal":{"name":"Frontiers in Earth Science","volume":"356 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141872469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}