Article
Geosciences, Multidisciplinary
Hai-Min Lyu, Shui-Long Shen, Yong-Xia Wu, An-Nan Zhou
Summary: This paper analyzes the mechanism of blocking effects from a close barrier in confined aquifer and proposes a simple equation based on analytical solution to calculate groundwater heads inside and outside of the excavation pit with a waterproof curtain. The distribution of groundwater head is derived under two conditions: pumping with a constant water head and pumping with a constant flow rate. The proposed model is verified by numerical simulation and experimental results, demonstrating its applicability in engineering practice.
GEOSCIENCE FRONTIERS
(2021)
Article
Construction & Building Technology
Chao-Feng Zeng, Wei-Wei Song, Xiu-Li Xue, Miao-Kun Li, Ning Bai, Guo-Xiong Mei
Summary: The study investigated the effects of buttress retaining walls on ground settlement during construction dewatering. Results showed that buttress walls significantly reduce ground settlement caused by foundation pit dewatering, with longer walls achieving greater reduction. However, the deformation-restraining efficiency of buttress walls reduces as their length increases in conditions with small drawdown from dewatering.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Miao Jing, Chunhui Lu, Chaojun Sun, Estanislao Pujades, Yu Ye, Teng Xu, Xiaowen Sun
Summary: This paper presents a novel analytical approach to estimate groundwater travel time distribution in urban areas, considering the impervious urban structure and modified aquifer hydraulic properties. The proposed analytical model is verified through comparison with numerical results and sensitivity analysis. The results show that urban groundwater travel time distribution is strongly dependent on construction-related parameters and aquifer compressibility, suggesting the need for adaptive groundwater management strategies for different aquifer types. The proposed model has important implications for water resources management, urban groundwater utilization, and aquifer quality in urban areas.
HYDROGEOLOGY JOURNAL
(2023)
Article
Engineering, Geological
Hisham T. Eid, Mohammed Z. E. B. Elshafie, Barry O'Sullivan, Alhassan Mahmoud, Reiner Stollberg
Summary: A comprehensive analysis of dewatering and pumping-well systems in fractured rock was conducted to estimate permeability. The study is an advancement in the field as most related studies focus on directional permeability. The analyses revealed a significant discrepancy between estimated and measured permeabilities, which increases with higher permeability. A novel correlation and estimation procedure based on measured permeability and rock fracturing degree were developed.
ENGINEERING GEOLOGY
(2023)
Article
Construction & Building Technology
Chao-Feng Zeng, Xiu-Li Xue, Miao-Kun Li
Summary: The study investigates the feasibility of using a cross wall to restrict pit deformations during pre-excavation dewatering, and discusses the effect of cross wall spacing on deformation control. The results show that as the spacing decreases, deformation decreases, but there is a critical spacing that plays a significant role in restraining the deformation.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2021)
Article
Engineering, Civil
Chao-Feng Zeng, Hong -Bo Chen, Huan Liao, Xiu-Li Xue, Qiu-Nan Chen, Yu Diao
Summary: When an excavation is close to an existing underground structure that penetrates aquifers, the structure can change groundwater seepage and restrict strata movement, resulting in water-blocking and soil-blocking effects. The barrier effect of a metro station as an underground structure was investigated numerically in this study. The results show that considering the barrier effect reduces the overall water yield of the excavation while increasing the induced groundwater drawdown. The behavior of strata under the barrier effect is more complex and depends on the coupled action of water-blocking and soil-blocking effects, which are influenced by the excavation width and distance between the station and the excavation.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Jasper J. L. Hoffmann, Joshu J. Mountjoy, Erica Spain, Mark Gall, Leigh W. Tait, Yoann Ladroit, Aaron Micallef
Summary: Fresh submarine groundwater discharge (FSGD) is important in coastal areas and can be used as an indicator for potential untapped offshore freshened groundwater (OFG) resources. However, the connection between onshore and offshore areas and the recharge characteristics of offshore aquifers are poorly understood, making the exploitation of this resource challenging. This study evaluates different methodologies to map the spatial extent of FSGD sites and determine their geomorphologic expressions on the seafloor, using a multidisciplinary dataset and novel sensing strategies.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Engineering, Civil
Huiqiang Wu, Chunhui Lu, Chengji Shen, Yu Ye
Summary: This study presents an analytical methodology for predicting the extent of seawater intrusion and the maximum safe extraction rate in a rectangular coastal aquifer with a subsurface physical barrier. The proposed method is consistent with numerical results and offers a simple alternative to 3D modeling for assessing engineered barriers in coastal aquifers.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Tengyun Xue, Xiuli Xue, Sichun Long, Qiunan Chen, Shide Lu, Chaofeng Zeng
Summary: A numerical model was developed to study the characteristics of groundwater flow and strata movement induced by dewatering and excavation with consideration of the barrier effect of pre-existing underground structures. The influence of adjacent structures on the movement of groundwater and strata was revealed through comparing different working conditions. The results showed that pile foundations have different effects on groundwater flow and excavation deformation.
Article
Engineering, Civil
Chao-Feng Zeng, Shuo Wang, Xiu-Li Xue, Gang Zheng, Guo-Xiong Mei
Summary: Dewatering of foundation pits can lead to environmental issues such as ground settlement. Studies show that the location of the greatest settlement induced by dewatering can vary, appearing either in deep aquifers or at the ground surface. Different dewatering conditions affect the evolution of the LoGS.
JOURNAL OF HYDROLOGY
(2021)
Article
Engineering, Civil
Yunhai Fang, Jiazhong Qian, Tianyuan Zheng, Huan Wang, Xilai Zheng, Marc Walther
Summary: Submarine groundwater discharge (SGD) plays a crucial role in coastal water quality and ecology. This study investigated the impact of subsurface physical barriers on freshwater and saline water inflows using laboratory experiments and numerical simulations. The results showed that different structures of subsurface physical barriers had varied effects on the location of freshwater discharge at the aquifer-sea interface.
JOURNAL OF HYDROLOGY
(2023)
Article
Geosciences, Multidisciplinary
Ndubuisi Igwebuike, Innocent Muchingami, Thokozani Kanyerere
Summary: The lack of using hydrogeophysics and hydraulic data in setting up a sustainable managed aquifer recharge scheme leads to challenges in operations and maintenance of such infrastructures. This study aimed at improving knowledge on aquifer dynamics for managed aquifer recharge scheme using hydrogeophysics and diagnostic plots. The integration of hydrogeophysics and diagnostic plots provided a more practical interpretation for the study area.
JOURNAL OF AFRICAN EARTH SCIENCES
(2023)
Article
Green & Sustainable Science & Technology
Yong Gui, Nana Li, Sihai Luo, Guanshi Wang
Summary: Lack of a reliable design method for the leaching and seepage step of in situ leaching (ISL) leads to problems such as low resource recovery rate and frequent geological disasters. This study established a simplified liquid injection-collection plane model of ISL and derived the steady seepage line equation based on groundwater dynamics and the Dupuit assumption. The equation was verified through engineering verification and calculation error analysis, and it can provide a theoretical basis for the prior prediction and design of the liquid injection/collection leaching and seepage process in ISL.
Article
Environmental Sciences
Haile A. Shishaye, Douglas R. Tait, Damien T. Maher, Kevin M. Befus, Dirk Erler, Luke Jeffrey, Michael J. Reading, Uwe Morgenstern, Sarit Kaserzon, Jochen Mueller, Wanda De Verelle-Hill
Summary: Nutrient and pesticide pollution pose significant threats to groundwater quality in agriculturally impacted aquifers. This study in Australia's Great Barrier Reef catchment area used tritium sampling and isotopic analysis to investigate groundwater contamination and nitrate dynamics. The research highlighted the influence of nitrification processes and geological heterogeneity on nutrient dynamics in the aquifer system.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Davide Sartirana, Chiara Zanotti, Marco Rotiroti, Mattia De Amicis, Mariachiara Caschetto, Agnese Redaelli, Letizia Fumagalli, Tullia Bonomi
Summary: Urbanization worldwide has led to increased use of the subsurface, resulting in significant groundwater and underground infrastructure interactions. This study utilized numerical models to simulate underground infrastructures and quantify infiltrations. The findings demonstrated that subway tunnels were the most affected areas, and the method successfully quantified infiltrations caused by interaction with the water table.
Article
Engineering, Geological
Tao Yan, Shui-Long Shen, Annan Zhou
Summary: This paper proposes a framework to identify geological characteristics using a fuzzy C-means algorithm based on borehole data and operational data. The identified factors are significantly reduced by principal component analysis, and the types of geological characteristics are determined using the fuzzy C-means model.
Article
Engineering, Geological
Pierre Guy Atangana Njock, Ning Zhang, Annan Zhou, Shui-Long Shen
Summary: This study proposes an improved random forest (IRF) model to evaluate ground displacement caused by jet grouting. By integrating a hybrid particle swarm optimization-simulated annealing algorithm (PSO-SA) into random forest, the IRF model shows better searching and convergence abilities compared to its counterparts. The results demonstrate that the IRF model outperforms benchmark models in predicting ground displacement. Additionally, the analysis of variable importance shows that ground lateral displacement can be controlled through two operating parameters.
GEOTECHNICAL AND GEOLOGICAL ENGINEERING
(2023)
Article
Environmental Sciences
Khalid Elbaz, Ibrahim Hoteit, Wafaa Mohamed Shaban, Shui-Long Shen
Summary: A novel deep-learning method was proposed to extract spatiotemporal features for air pollution concentration prediction, and a health risk assessment was conducted in NEOM City. The results showed that the proposed method significantly improved the accuracy of air quality forecasting compared to existing models.
Article
Environmental Sciences
Tao Yan, Annan Zhou, Shui-Long Shen
Summary: A new framework for predicting long-term water quality is proposed using Bayesian-optimized machine learning methods and key pollution indicators. The SG-op model achieves the best performance with high accuracy and Kappa coefficient. The framework can efficiently predict future water quality and provide technical support for emergency pollution control.
ENVIRONMENTAL POLLUTION
(2023)
Article
Green & Sustainable Science & Technology
Pierre Guy Atangana Njock, Annan Zhou, Zhenyu Yin, Shui-Long Shen
Summary: This study proposes a flexible methodology for quantifying the risk status of coastal subbasins, which integrates the characteristics of multi-criteria analysis and fuzzy set theory. The methodology includes constructing a risk index to reveal the extent of cumulative nutrients discharges. The application of the proposed model in the Baltic Sea shows an increasing trend of risk index over the years and aligns well with field observations and HELCOM predictions.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Chemical
Xin Liu, Annan Zhou, Kai Sun, Shui-Long Shen
Summary: In this study, the influence of suction on the macro/micro-mechanical behaviour of unsaturated soil was investigated through a series of three-dimensional simulations using the discrete element method. The results were compared with laboratory test results to understand the relationship between macroscopic behavior and micro-mechanical variables.
Article
Construction & Building Technology
Shui-Long Shen, Tao Yan, Annan Zhou
Summary: This paper presents an approach for estimating the locations of the soil-rock interfaces during shield tunnelling based on vibration data. The vibration data were collected using accelerometers on the back of the soil chamber wall. The continuous wavelet transform was used to analyze the time-frequency spectrum of the acceleration and identify vibration peaks. The approach was validated on the Guangzhou-Foshan intercity railway project.
AUTOMATION IN CONSTRUCTION
(2023)
Article
Engineering, Geological
Song-Shun Lin, Annan Zhou, Shui-Long Shen
Summary: Risk events in karst geological environments during excavation construction can be reduced by implementing a suitable risk-control scheme. This study proposes a decision-making approach based on the fuzzy VIKOR method to identify the optimal risk-control scheme. The approach uses a triangular fuzzy set for expressing expert judgements and constructs a decision hierarchy based on four criteria and 12 sub-criteria. The identified scheme, involving pressure grouting with a two-phase liquid system, was validated through core recovery and modified number of blows using a standard penetration test. A flowchart for optimal scheme identification in geotechnical engineering practice is also provided.
CANADIAN GEOTECHNICAL JOURNAL
(2023)
Article
Environmental Sciences
Yu -Lin Chen, Lin-Shuang Zhao, Annan Zhou, Shui-Long Shen
Summary: This paper presents a case study on the hazards of red tides in the Pearl River Estuary. Data on red tide hazards, meteorology, and seawater monitoring were collected from 1996 to 2020 in different locations around the estuary to investigate the factors influencing red tide occurrences. The ASSETS method was used to evaluate the effects of meteorological factors and seawater eutrophication on the risk level of red tides. The study established a framework for red tide risk assessment and identified external and internal factors contributing to red tide formation.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Geological
Ning Zhang, Annan Zhou, Yin-Fu Jin, Zhen-Yu Yin, Shui-Long Shen
Summary: The study proposes an enhanced deep learning method to address the accuracy issue in neural network-based methods for soil stress-strain response. The enhanced method significantly improves accuracy, extrapolation capacity, and robustness. A rationality investigation is conducted into the weight gradient variation in neural networks. The effectiveness is verified through three stress-strain responses of soil, demonstrating improved predictive accuracy and robustness against errors.
Article
Engineering, Geological
Wei Cao, Annan Zhou, Shui-Long Shen
Summary: This paper proposes a coupled method for characterizing the stratigraphic uncertainty and rotated anisotropy of soil properties, and investigates the unsaturated soil slope stability considering the two uncertainties. The results show that the proposed method can well characterize the two uncertainties at the same time, and the rotational anisotropy of soil properties has a substantial impact on the slope stability and groundwater table.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Engineering, Civil
Yi Zeng, Pierre Guy Atangana Njock, Wang Xiong, Xiao-Long Zhang, Shui-Long Shen
Summary: This paper presents a case study on the identification and management of geological and environmental risks during the construction of the largest slurry shield tunnel in China. The ground conditions and settlement control were challenging due to mixed ground conditions, fault zones, and tunneling under residential areas and Metro Lines. Novel monitoring systems, ground treatment, and safety management technologies were successfully implemented. A technical framework was proposed as a risk management guidance for similar tunneling operations.
Article
Energy & Fuels
Shui-Long Shen, Pierre Guy Atangana Njock, Annan Zhou
Summary: This paper investigates the effect of nozzle structure on efficiency of jet flow and determines the optimal nozzles for jet grouting operations through a combination of field experiment, numerical simulation, and multicriteria decision analysis. The results show that 4 out of the 10 structures investigated achieved the steadiest jetting pressure attenuation along different standoff distances, while satisfying the required driving pressure and flow rate. The study identified the converging section as critical for the conversion of viscous force within the nozzle and determined the optimal nozzle structure based on parameters such as L2 and theta.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Environmental Sciences
Khalid Elbaz, Wafaa Mohamed Shaban, Annan Zhou, Shui-Long Shen
Summary: This study proposes an image-based deep learning method that improves air quality recognition and produces accurate multiple horizon forecasts. The proposed model combines a 3D-CNN, a GRU, and an attention mechanism to extract hidden features, recognize environmental variables, extract temporal features, and adjust the influence of features to avoid fluctuations in air pollutant values. Experimental results show that the proposed method outperforms other state-of-the-art methods in terms of forecasting accuracy.
Article
Construction & Building Technology
Tao Yan, Shui-Long Shen, Annan Zhou
Summary: Geological features are crucial for the safety and efficiency of shield tunnelling, but they are often concealed and difficult to observe. To address this issue, a novel index called Geological Feature Identification Index (GFII) has been introduced to evaluate the impact of geological conditions on shield tunnelling. The results show that cutterhead torque and shield thrust weights are significantly affected by various geological features, with the entropy-weighted GFII demonstrating superior performance.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)