Engineering Geology最新文献_第2页

Landslide-reinforcement method and its application based on jet grouting to improve sliding-soil strength

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-18 DOI: 10.1016/j.enggeo.2025.107976

Bolin Chen , Haiyou Peng , Wenjun Yang , Si Chen , Peizhe Zhang , Xiaoming Ye , Qi Guo , Shuang Wei , Hao Mei

Owing to its versatility in civil-engineering applications such as slope stabilisation, foundation consolidation, and tunnel construction, jet grouting has been lauded for its swift implementation, cost effectiveness, and high structural integrity. This study introduces an innovative framework and procedural technique for landslide reinforcement using jet grouting. Using the transfer-coefficient method, we develop an integrated strength model that encompasses the altered mechanical attributes of soil layers following jet-grouting treatment at the slide interface. This model underpins a bespoke stability calculation formula for landslides reinforced by jet grouting. The Sanhepu landslide is used as a case study, where the methodology unfolds across the testing, reinforcement-scheme design, project-execution, and monitoring phases. Our study shows that jet grouting substantially enhances the shear strength of sliding soil, with the treated soil exhibiting greater strength than its interface with a rock. A strategic reinforcement plan that considers the positioning, spacing, and height of jet-grouting columns is shown to significantly improve landslide stability. The stability coefficient for the Sanhepu site increases significantly from 1.184 before intervention to 1.453 after intervention. The theoretical findings are applied in practice to the Sanhepu landslide, with emphasis on targeted sliding-soil reinforcement. Post-intervention monitoring substantiates the stabilisation and confirms the effectiveness of the jet-grouting method for soils susceptible to sliding.

{"title":"Landslide-reinforcement method and its application based on jet grouting to improve sliding-soil strength","authors":"Bolin Chen , Haiyou Peng , Wenjun Yang , Si Chen , Peizhe Zhang , Xiaoming Ye , Qi Guo , Shuang Wei , Hao Mei","doi":"10.1016/j.enggeo.2025.107976","DOIUrl":"10.1016/j.enggeo.2025.107976","url":null,"abstract":"<div><div>Owing to its versatility in civil-engineering applications such as slope stabilisation, foundation consolidation, and tunnel construction, jet grouting has been lauded for its swift implementation, cost effectiveness, and high structural integrity. This study introduces an innovative framework and procedural technique for landslide reinforcement using jet grouting. Using the transfer-coefficient method, we develop an integrated strength model that encompasses the altered mechanical attributes of soil layers following jet-grouting treatment at the slide interface. This model underpins a bespoke stability calculation formula for landslides reinforced by jet grouting. The Sanhepu landslide is used as a case study, where the methodology unfolds across the testing, reinforcement-scheme design, project-execution, and monitoring phases. Our study shows that jet grouting substantially enhances the shear strength of sliding soil, with the treated soil exhibiting greater strength than its interface with a rock. A strategic reinforcement plan that considers the positioning, spacing, and height of jet-grouting columns is shown to significantly improve landslide stability. The stability coefficient for the Sanhepu site increases significantly from 1.184 before intervention to 1.453 after intervention. The theoretical findings are applied in practice to the Sanhepu landslide, with emphasis on targeted sliding-soil reinforcement. Post-intervention monitoring substantiates the stabilisation and confirms the effectiveness of the jet-grouting method for soils susceptible to sliding.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"349 ","pages":"Article 107976"},"PeriodicalIF":6.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal-fluid coupled fracture behavior of fissured granite in a 3D crystal model

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-17 DOI: 10.1016/j.enggeo.2025.107974

Heng Li , Sheng-Qi Yang , Bo-Wen Sun , Zhen Yang , Zhi-Jin Dong , Pin-Qiang Mo

The discontinuous geological structures and crystalline characteristics of granite reservoirs drive hydraulic fracturing behavior, significantly influencing the process and effectiveness of reservoir stimulation. This paper introduces an improved three-dimensional thermo-hydro-mechanical coupled peridynamic crystal model (THM-PDCM) incorporating thermal cracking, nonlinear mechanics, and hydraulic effects. A polycrystalline microstructure model was developed based on the “crystal growth algorithm.” Within this framework, the effects of temperature, fissure dip angle and loading conditions on the hydraulic fracture propagation mechanism in granite were systematically investigated. Results show that THM-PDCM accurately captures thermally induced damage, fluid-driven fracture, and mechanical interactions. Grain boundary effects significantly influence the initiation and propagation of fractures. High temperatures induce microcracks that reduce the fracture toughness of the rock, alter crack propagation directions, and increase propagation instability. Thermally induced cracking combined with cold-water diffusion accelerates fracture growth, prompting transitions through crossing, propagation, deviation, and blocking as pressure declines.

{"title":"Thermal-fluid coupled fracture behavior of fissured granite in a 3D crystal model","authors":"Heng Li , Sheng-Qi Yang , Bo-Wen Sun , Zhen Yang , Zhi-Jin Dong , Pin-Qiang Mo","doi":"10.1016/j.enggeo.2025.107974","DOIUrl":"10.1016/j.enggeo.2025.107974","url":null,"abstract":"<div><div>The discontinuous geological structures and crystalline characteristics of granite reservoirs drive hydraulic fracturing behavior, significantly influencing the process and effectiveness of reservoir stimulation. This paper introduces an improved three-dimensional thermo-hydro-mechanical coupled peridynamic crystal model (THM-PDCM) incorporating thermal cracking, nonlinear mechanics, and hydraulic effects. A polycrystalline microstructure model was developed based on the “crystal growth algorithm.” Within this framework, the effects of temperature, fissure dip angle and loading conditions on the hydraulic fracture propagation mechanism in granite were systematically investigated. Results show that THM-PDCM accurately captures thermally induced damage, fluid-driven fracture, and mechanical interactions. Grain boundary effects significantly influence the initiation and propagation of fractures. High temperatures induce microcracks that reduce the fracture toughness of the rock, alter crack propagation directions, and increase propagation instability. Thermally induced cracking combined with cold-water diffusion accelerates fracture growth, prompting transitions through crossing, propagation, deviation, and blocking as pressure declines.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"349 ","pages":"Article 107974"},"PeriodicalIF":6.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seasonal dynamics of root growth and desiccation cracks and their effects on soil hydraulic conductivity

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-17 DOI: 10.1016/j.enggeo.2025.107973

Yuliana Yuliana , Arwan Apriyono , Viroon Kamchoom , David Boldrin , Qing Cheng , Chao-Sheng Tang

Vegetation significantly influences soil hydraulic conductivity, with the extent of this influence depending on root morphology and density, which vary across different developmental stages of plants. This research investigates the interaction dynamics between plant roots (during both growth and decay) and desiccation cracks, as well as the combined impact of vegetation, cracks, and seasonal variations on soil hydraulic conductivity (K_sat). Root growth and decay patterns were observed using a minirhizotron, while changes in crack formation were monitored and interpreted using the Crack Intensity Factor (CIF) for both vegetated and bare areas over an eighteen-month period of wetting and drying cycles. K_sat was analysed based on data from a double-ring test. The findings indicate that the presence of vetiver roots results in a less visible and uneven crack distribution compared to bare soil, with CIF and average crack widths reduced by half. However, cracks reappear during root decay periods. Although cracks were minimised in vegetated soil, K_sat values increased significantly during dry periods, with a 16-fold rise in the vegetated zone due to root propagation, while the bare zone showed a marginal 5-fold increase. The presence of cracks and roots significantly influences K_sat, exhibiting distinct hysteresis behaviour in response to drying and wetting cycles.

{"title":"Seasonal dynamics of root growth and desiccation cracks and their effects on soil hydraulic conductivity","authors":"Yuliana Yuliana , Arwan Apriyono , Viroon Kamchoom , David Boldrin , Qing Cheng , Chao-Sheng Tang","doi":"10.1016/j.enggeo.2025.107973","DOIUrl":"10.1016/j.enggeo.2025.107973","url":null,"abstract":"<div><div>Vegetation significantly influences soil hydraulic conductivity, with the extent of this influence depending on root morphology and density, which vary across different developmental stages of plants. This research investigates the interaction dynamics between plant roots (during both growth and decay) and desiccation cracks, as well as the combined impact of vegetation, cracks, and seasonal variations on soil hydraulic conductivity (K<sub>sat</sub>). Root growth and decay patterns were observed using a minirhizotron, while changes in crack formation were monitored and interpreted using the Crack Intensity Factor (CIF) for both vegetated and bare areas over an eighteen-month period of wetting and drying cycles. K<sub>sat</sub> was analysed based on data from a double-ring test. The findings indicate that the presence of vetiver roots results in a less visible and uneven crack distribution compared to bare soil, with CIF and average crack widths reduced by half. However, cracks reappear during root decay periods. Although cracks were minimised in vegetated soil, K<sub>sat</sub> values increased significantly during dry periods, with a 16-fold rise in the vegetated zone due to root propagation, while the bare zone showed a marginal 5-fold increase. The presence of cracks and roots significantly influences K<sub>sat</sub>, exhibiting distinct hysteresis behaviour in response to drying and wetting cycles.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"349 ","pages":"Article 107973"},"PeriodicalIF":6.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Slip behaviors of rock joints subjected to weak shear disturbances: An experimental study

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-17 DOI: 10.1016/j.enggeo.2025.107971

Wei Yuan , Jianchun Li , Xing Li , Jiefang Jin

Frequent weak disturbances can induce dynamic shear slip along rock joints and potentially trigger dynamic hazards in rock masses. This study experimentally investigates the dynamic slip, failure, and instability behavior of jointed rocks under repeated shear disturbances. A custom dynamic shear testing apparatus was used to examine sawtooth-shaped rock joints subjected to weak shear disturbances, normal stress, and initial shear stress. The results reveal that the shear displacement of the joint progresses through three distinct stages: decelerated slip, constant-rate slip, and accelerated slip, forming an inverse S-shaped curve. Both the dynamic slip displacement caused by the disturbance and the post-disturbance deformation due to stress recovery in each cycle are captured. As disturbance cycles increase, a progressive instability process is identified, characterized by a transition from initial instability to stable damage accumulation, and finally to accelerated damage accumulation. Notably, all instabilities occurred during the stress recovery phase following the final disturbance. The effects of normal stress and joint undulation angle on these behaviors are also discussed. A combined linear-exponential model is proposed to quantify the shear slip in jointed rocks, incorporating a damage variable index. The p/a ratio in this model effectively describes the transition from stable to accelerated damage accumulation, which may also indicate the intensity of energy release. These findings provide guidance for the assessment of dynamic slip instability in jointed rock masses, particularly under far-field seismic events.

{"title":"Slip behaviors of rock joints subjected to weak shear disturbances: An experimental study","authors":"Wei Yuan , Jianchun Li , Xing Li , Jiefang Jin","doi":"10.1016/j.enggeo.2025.107971","DOIUrl":"10.1016/j.enggeo.2025.107971","url":null,"abstract":"<div><div>Frequent weak disturbances can induce dynamic shear slip along rock joints and potentially trigger dynamic hazards in rock masses. This study experimentally investigates the dynamic slip, failure, and instability behavior of jointed rocks under repeated shear disturbances. A custom dynamic shear testing apparatus was used to examine sawtooth-shaped rock joints subjected to weak shear disturbances, normal stress, and initial shear stress. The results reveal that the shear displacement of the joint progresses through three distinct stages: decelerated slip, constant-rate slip, and accelerated slip, forming an inverse S-shaped curve. Both the dynamic slip displacement caused by the disturbance and the post-disturbance deformation due to stress recovery in each cycle are captured. As disturbance cycles increase, a progressive instability process is identified, characterized by a transition from initial instability to stable damage accumulation, and finally to accelerated damage accumulation. Notably, all instabilities occurred during the stress recovery phase following the final disturbance. The effects of normal stress and joint undulation angle on these behaviors are also discussed. A combined linear-exponential model is proposed to quantify the shear slip in jointed rocks, incorporating a damage variable index. The <em>p</em>/<em>a</em> ratio in this model effectively describes the transition from stable to accelerated damage accumulation, which may also indicate the intensity of energy release. These findings provide guidance for the assessment of dynamic slip instability in jointed rock masses, particularly under far-field seismic events.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"350 ","pages":"Article 107971"},"PeriodicalIF":6.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Centrifuge modelling of a roto-translational landslide in stiff clay formation

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-17 DOI: 10.1016/j.enggeo.2025.107964

Peng Xin , Xuan Kang , Wei Wu , Gianvito Scaringi , Xueliang Wang , Qiong Wu

Roto-translational landslides usually exhibit creep deformation along sliding surfaces, showing transverse cracks on the ground surfaces. However, the scarcity of experimental data has significantly hindered a deep understanding of their failure mechanisms. This research probes into the rotational failure phenomena of landslides in stiff clay formations, utilizing geotechnical centrifuge modelling and laboratory creep tests. Our findings reveal that rotational failures in model slopes are exclusively triggered under conditions of an undrained boundary at the basal shear zone. The post-failure behaviour is characterized by a settlement at the slope crest and a pronounced bulge at the toe, resulting in complex rotational movements along the basal sliding surface. Moreover, our laboratory experiments illuminate the creep behaviour of shear-zone materials under undrained conditions. In particular, samples with a high initial water content under sustained loading are highly susceptible to a quick transition into tertiary creep, leading to accelerated failure. These experimental insights substantially advance our understanding of the rotational failure patterns observed in clay-based landslides.

{"title":"Centrifuge modelling of a roto-translational landslide in stiff clay formation","authors":"Peng Xin , Xuan Kang , Wei Wu , Gianvito Scaringi , Xueliang Wang , Qiong Wu","doi":"10.1016/j.enggeo.2025.107964","DOIUrl":"10.1016/j.enggeo.2025.107964","url":null,"abstract":"<div><div>Roto-translational landslides usually exhibit creep deformation along sliding surfaces, showing transverse cracks on the ground surfaces. However, the scarcity of experimental data has significantly hindered a deep understanding of their failure mechanisms. This research probes into the rotational failure phenomena of landslides in stiff clay formations, utilizing geotechnical centrifuge modelling and laboratory creep tests. Our findings reveal that rotational failures in model slopes are exclusively triggered under conditions of an undrained boundary at the basal shear zone. The post-failure behaviour is characterized by a settlement at the slope crest and a pronounced bulge at the toe, resulting in complex rotational movements along the basal sliding surface. Moreover, our laboratory experiments illuminate the creep behaviour of shear-zone materials under undrained conditions. In particular, samples with a high initial water content under sustained loading are highly susceptible to a quick transition into tertiary creep, leading to accelerated failure. These experimental insights substantially advance our understanding of the rotational failure patterns observed in clay-based landslides.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"349 ","pages":"Article 107964"},"PeriodicalIF":6.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bayesian identification of the optimal soil-water characteristic curve (SWCC) model and reliability analysis of unsaturated loess slope from extremely sparse measurements

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-17 DOI: 10.1016/j.enggeo.2025.107975

Tengyuan Zhao, Yabin Yang, Ling Xu, Pingping Sun

Soil-water characteristic curve (SWCCs) are crucial in engineering geology and geotechnical engineering for understanding the behavior of unsaturated soils, such as loess, which directly affects permeability, shear strength, and volume change-key factors in slope stability and soil-structure interactions. Conventionally, SWCC estimation relies on multiple (saying approximately ten) measurements fitted to parameterized models. However, in practical applications, especially for medium- or small-scale projects, the availability of SWCC measurements is often extremely limited (e.g., one or two measurements) due to the time-intensive nature of the experiments. This presents significant challenges in accurately identifying suitable SWCC models and performing reliable stability analyses for unsaturated soil slopes. To address these challenges, this study employs a hierarchical Bayesian framework that integrates information from similar geotechnical site, enabling robust SWCC estimation and model selection from minimal measurements with the aid of Markov Chain Monte Carlo (MCMC) sampling, thereby quantifying model uncertainties and providing more scientifically informed decision-making for construction in engineering geology. MCMC samples obtained further facilitate both the identification of the most suitable SWCC model and the quantification of associated uncertainties. Then, a reliability-based stability analysis of an unsaturated loess slope is conducted, using the optimal SWCC model and its quantified uncertainty. The proposed methodology is validated through a real-world case study, demonstrating its effectiveness in deriving reliable SWCC models and performing stability analyses under conditions of extremely sparse data. The results highlight the potential of this method as a practical tool for advancing reliability assessments of unsaturated soil slopes in engineering geology.

{"title":"Bayesian identification of the optimal soil-water characteristic curve (SWCC) model and reliability analysis of unsaturated loess slope from extremely sparse measurements","authors":"Tengyuan Zhao, Yabin Yang, Ling Xu, Pingping Sun","doi":"10.1016/j.enggeo.2025.107975","DOIUrl":"10.1016/j.enggeo.2025.107975","url":null,"abstract":"<div><div>Soil-water characteristic curve (SWCCs) are crucial in engineering geology and geotechnical engineering for understanding the behavior of unsaturated soils, such as loess, which directly affects permeability, shear strength, and volume change-key factors in slope stability and soil-structure interactions. Conventionally, SWCC estimation relies on multiple (saying approximately ten) measurements fitted to parameterized models. However, in practical applications, especially for medium- or small-scale projects, the availability of SWCC measurements is often extremely limited (e.g., one or two measurements) due to the time-intensive nature of the experiments. This presents significant challenges in accurately identifying suitable SWCC models and performing reliable stability analyses for unsaturated soil slopes. To address these challenges, this study employs a hierarchical Bayesian framework that integrates information from similar geotechnical site, enabling robust SWCC estimation and model selection from minimal measurements with the aid of Markov Chain Monte Carlo (MCMC) sampling, thereby quantifying model uncertainties and providing more scientifically informed decision-making for construction in engineering geology. MCMC samples obtained further facilitate both the identification of the most suitable SWCC model and the quantification of associated uncertainties. Then, a reliability-based stability analysis of an unsaturated loess slope is conducted, using the optimal SWCC model and its quantified uncertainty. The proposed methodology is validated through a real-world case study, demonstrating its effectiveness in deriving reliable SWCC models and performing stability analyses under conditions of extremely sparse data. The results highlight the potential of this method as a practical tool for advancing reliability assessments of unsaturated soil slopes in engineering geology.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"349 ","pages":"Article 107975"},"PeriodicalIF":6.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geothermal potential in Singapore explored with non-invasive seismic data 利用非侵入式地震数据勘探新加坡的地热潜力

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-15 DOI: 10.1016/j.enggeo.2025.107968

Yiming Bai , Shijie Hao , Jinyun Xie , Mijian Xu , Xiao Xiao , Jing Chen , Chun Fei Chey , Dongdong Wang , Ping Tong

Singapore is dedicated to developing geothermal resources to meet rising energy demand and achieve net-zero emissions by 2050. While above-average heat flow and local hot springs suggest high geothermal potential beneath Singapore, the associated deep thermal sources remain underexplored due to a limited understanding of the subsurface structure. Applying ambient noise tomography and converted/reflected body-wave imaging to new seismic data from North Singapore reveals a highly fractured, fluid-saturated shallow geothermal reservoir located southeast of the Sembawang Hot Spring in the Yishun district. This reservoir exhibits low Vs (< 3.2 km/s) and high Vp/Vs (> 2.1). At a greater depth of ∼4 km, a crustal seismic discontinuity indicates a transition from the upper Bukit Timah Granite to the porous metasedimentary basement, where a deep aquifer might form, supplying the shallow reservoir and, ultimately, the Sembawang Hot Spring through the fault and fracture system. Our results highlight Yishun as a potential site for deep drilling in future geothermal explorations, and more broadly, provide new insights into the deep heat sources of numerous medium-to-low enthalpy geothermal sites throughout the Southeast Asian batholiths.

{"title":"Geothermal potential in Singapore explored with non-invasive seismic data","authors":"Yiming Bai , Shijie Hao , Jinyun Xie , Mijian Xu , Xiao Xiao , Jing Chen , Chun Fei Chey , Dongdong Wang , Ping Tong","doi":"10.1016/j.enggeo.2025.107968","DOIUrl":"10.1016/j.enggeo.2025.107968","url":null,"abstract":"<div><div>Singapore is dedicated to developing geothermal resources to meet rising energy demand and achieve net-zero emissions by 2050. While above-average heat flow and local hot springs suggest high geothermal potential beneath Singapore, the associated deep thermal sources remain underexplored due to a limited understanding of the subsurface structure. Applying ambient noise tomography and converted/reflected body-wave imaging to new seismic data from North Singapore reveals a highly fractured, fluid-saturated shallow geothermal reservoir located southeast of the Sembawang Hot Spring in the Yishun district. This reservoir exhibits low <em>Vs</em> (< 3.2 km/s) and high <em>Vp</em>/<em>Vs</em> (> 2.1). At a greater depth of ∼4 km, a crustal seismic discontinuity indicates a transition from the upper Bukit Timah Granite to the porous metasedimentary basement, where a deep aquifer might form, supplying the shallow reservoir and, ultimately, the Sembawang Hot Spring through the fault and fracture system. Our results highlight Yishun as a potential site for deep drilling in future geothermal explorations, and more broadly, provide new insights into the deep heat sources of numerous medium-to-low enthalpy geothermal sites throughout the Southeast Asian batholiths.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"348 ","pages":"Article 107968"},"PeriodicalIF":6.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolution of large landslides in tectonically active regions - A decade of observations in the Zhouqu County, China

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-14 DOI: 10.1016/j.enggeo.2025.107967

Yi Zhang , Yuanxi Li , Tom Dijkstra , Janusz Wasowski , Xingmin Meng , Xiang Wu , Wangcai Liu , Guan Chen

The Zhouqu region is located in the middle reaches of the Bailong River in southern Gansu Province. It is recognised as one of the most active geohazards regions in China. This paper presents more than a decade of observations (2010−2023) of the evolution of landslides along an active fault zone in the Zhouqu region. A varied lithology comprises shales and phyllites in a fault-controlled geomorphology that conditions the slopes and has resulted in large ancient landslide complexes. The activity of these landslides was assessed using InSAR (Interferometric Synthetic Aperture Radar), a technique capable of generating historical and recent ground deformation data. These assessments were validated through field investigations. The region hosts 31 active landslides, including four large ancient landslides with areas greater than 1 km², each displaying velocities exceeding 320 mm/year between February 2017 and August 2023. These landslides cover an area of approximately 35.7 km², some 16.4 % of the Zhouqu region (218 km²). The findings suggest that tectonic activity and lithology play critical roles in landslide and landscape development. Gradual changes in climate have the potential substantially alter the precipitation regime, which affects the stability of slopes and the mobility of large, slow-moving landslides. This research highlights the need for long-term monitoring (InSAR plus fieldwork) to achieve a better understanding of the evolution of large landslide in such dynamic regions that are influenced by tectonic, climatic and anthropogenic conditions. This knowledge adds to our understanding of the ways in which humans influence and, in turn, will be influenced by these large slope deformation processes in these dynamic terrains.

{"title":"Evolution of large landslides in tectonically active regions - A decade of observations in the Zhouqu County, China","authors":"Yi Zhang , Yuanxi Li , Tom Dijkstra , Janusz Wasowski , Xingmin Meng , Xiang Wu , Wangcai Liu , Guan Chen","doi":"10.1016/j.enggeo.2025.107967","DOIUrl":"10.1016/j.enggeo.2025.107967","url":null,"abstract":"<div><div>The Zhouqu region is located in the middle reaches of the Bailong River in southern Gansu Province. It is recognised as one of the most active geohazards regions in China. This paper presents more than a decade of observations (2010−2023) of the evolution of landslides along an active fault zone in the Zhouqu region. A varied lithology comprises shales and phyllites in a fault-controlled geomorphology that conditions the slopes and has resulted in large ancient landslide complexes. The activity of these landslides was assessed using InSAR (Interferometric Synthetic Aperture Radar), a technique capable of generating historical and recent ground deformation data. These assessments were validated through field investigations. The region hosts 31 active landslides, including four large ancient landslides with areas greater than 1 km<sup>2</sup>, each displaying velocities exceeding 320 mm/year between February 2017 and August 2023. These landslides cover an area of approximately 35.7 km<sup>2</sup>, some 16.4 % of the Zhouqu region (218 km<sup>2</sup>). The findings suggest that tectonic activity and lithology play critical roles in landslide and landscape development. Gradual changes in climate have the potential substantially alter the precipitation regime, which affects the stability of slopes and the mobility of large, slow-moving landslides. This research highlights the need for long-term monitoring (InSAR plus fieldwork) to achieve a better understanding of the evolution of large landslide in such dynamic regions that are influenced by tectonic, climatic and anthropogenic conditions. This knowledge adds to our understanding of the ways in which humans influence and, in turn, will be influenced by these large slope deformation processes in these dynamic terrains.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"348 ","pages":"Article 107967"},"PeriodicalIF":6.9,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatial multi criteria analysis of ground conditions in early stages railway planning using analytical hierarchy process applied to viaduct-type rail in Southern Sweden.

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-14 DOI: 10.1016/j.enggeo.2025.107962

Joakim Robygd , Lars Harrie , Tina Martin

This study applies a spatial multi-criteria analysis to assess ground suitability for pier-supported viaduct railways using the Analytical Hierarchy Process (AHP). By integrating expert judgments, the analysis evaluates six key geotechnical categories—soil type, soil depth, rock type, slope, wetness index, and groundwater occurrence—to map ground suitability. Three weight normalisation methods were tested to explore how different normalisation approaches affect the resulting suitability assessments. The results reveal significant variations in suitability maps, highlighting how different expert weighting strategies can influence decision-making during early-stage railway planning. Uncertainty maps were generated and used to identify areas requiring further investigation. The methodology is applied to an area in Southern Sweden, between the cities of Lund and Hässleholm to compare the weighting strategies over a relevant and geologically diverse area. A practical application comparing foundation types along identified routes showed that AHP-guided pathfinding achieved a clear preference for ground conditions suitable for non-piled foundations compared to a reference line. The method provides a systematic framework for preliminary geotechnical evaluations in railway planning, enabling more focused site investigations and supporting industrialized construction approaches.

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引用次数: 0

Pore-scale investigation of water-CO2-oil flow in shale fractures for enhanced displacement efficiency and CO2 sequestration

IF 6.9 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Engineering Geology

Pub Date : 2025-02-13 DOI: 10.1016/j.enggeo.2025.107969

Xiangjie Qin , Han Wang , Yuxuan Xia , Xinghe Jiao , Gang Wang , Jianchao Cai

CO₂ geological sequestration plays an important role in energy and environmental sustainability. However, CO₂ channeling through fracture networks in shale reservoirs reduces sequestration efficiency. Injecting CO₂ followed by water flooding, driven by capillary forces, can suppress CO₂ channeling and enhance sequestration. This work establishes pore-scale models for CO₂-oil and water-CO₂-oil flows within three-dimensional shale fractures to explain this underlying mechanism. The volume of fluid method is employed to integrate the immiscible flow between water and a mixture fluid comprising CO₂ and oil, wherein the interaction between CO₂ and oil remains miscible and is governed by molecular convection-diffusion. The effects of contact angle, injection rate, and CO₂ volume on displacement are analyzed. The results show that high injection rates of CO₂ enhance the mass transfer between CO₂ and oil components, with the injection rate positively correlating with displacement efficiency. Water flooding following CO₂ injection suppresses CO₂ channeling attributable to capillary effects, resulting in an approximately 20 % enhancement in oil recovery compared to CO₂ flooding. Although a substantial volume of CO₂ reduces displacement pressure, it leads to a premature breakthrough. An increase in contact angle results in a large amount of mixture fluid being trapped in blind-end pores, corresponding to unsatisfactory displacement effects. Nonetheless, an increased water injection rate augments the contact between the water and the mixture fluid, facilitating CO₂ dissolution. This results in a gradual decline in outlet mass flow and enhancements in oil recovery and CO₂ sequestration efficiency.

{"title":"Pore-scale investigation of water-CO2-oil flow in shale fractures for enhanced displacement efficiency and CO2 sequestration","authors":"Xiangjie Qin , Han Wang , Yuxuan Xia , Xinghe Jiao , Gang Wang , Jianchao Cai","doi":"10.1016/j.enggeo.2025.107969","DOIUrl":"10.1016/j.enggeo.2025.107969","url":null,"abstract":"<div><div>CO<sub>2</sub> geological sequestration plays an important role in energy and environmental sustainability. However, CO<sub>2</sub> channeling through fracture networks in shale reservoirs reduces sequestration efficiency. Injecting CO<sub>2</sub> followed by water flooding, driven by capillary forces, can suppress CO<sub>2</sub> channeling and enhance sequestration. This work establishes pore-scale models for CO<sub>2</sub>-oil and water-CO<sub>2</sub>-oil flows within three-dimensional shale fractures to explain this underlying mechanism. The volume of fluid method is employed to integrate the immiscible flow between water and a mixture fluid comprising CO<sub>2</sub> and oil, wherein the interaction between CO<sub>2</sub> and oil remains miscible and is governed by molecular convection-diffusion. The effects of contact angle, injection rate, and CO<sub>2</sub> volume on displacement are analyzed. The results show that high injection rates of CO<sub>2</sub> enhance the mass transfer between CO<sub>2</sub> and oil components, with the injection rate positively correlating with displacement efficiency. Water flooding following CO<sub>2</sub> injection suppresses CO<sub>2</sub> channeling attributable to capillary effects, resulting in an approximately 20 % enhancement in oil recovery compared to CO<sub>2</sub> flooding. Although a substantial volume of CO<sub>2</sub> reduces displacement pressure, it leads to a premature breakthrough. An increase in contact angle results in a large amount of mixture fluid being trapped in blind-end pores, corresponding to unsatisfactory displacement effects. Nonetheless, an increased water injection rate augments the contact between the water and the mixture fluid, facilitating CO<sub>2</sub> dissolution. This results in a gradual decline in outlet mass flow and enhancements in oil recovery and CO<sub>2</sub> sequestration efficiency.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"348 ","pages":"Article 107969"},"PeriodicalIF":6.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0