The traditional Green-Ampt model does not accurately represent the infiltration behavior of clay soils.Infiltration in clay is influenced by low hydraulic conductivity,strong capillary forces,and a gradual transition ...The traditional Green-Ampt model does not accurately represent the infiltration behavior of clay soils.Infiltration in clay is influenced by low hydraulic conductivity,strong capillary forces,and a gradual transition zone between saturated and unsaturated zones.These factors often lead to overestimated infiltration rates and underestimated infiltration durations.Therefore,it is necessary to improve the model to better reflect the characteristics of clay infiltration and enhance its predictive accuracy and practical applicability.This study conducts hydraulic characterization tests,one-dimensional soil column rainfall infiltration experiments,and numerical analysis on a representative clay sampled from Wuhan,China,to investigate infiltration behaviors under varying rainfall intensities and initial moisture conditions.The study reveals that the proportion of the transition layer within the wetting layer decreases with increasing wetting front depth,following a power-law function.Under the same initial moisture content,this proportion tends to converge to a stable value regardless of rainfall intensity.In contrast,under the same rainfall intensity,a higher initial moisture content leads to a larger proportion of the transition layer at a given wetting front depth.Based on the NMR curve,the unsaturated permeability coefficients corresponding to different volumetric water contents of clay can be obtained quickly,accurately,and at low cost.By utilizing the unsaturated permeability coefficient prediction model based on the nuclear magnetic resonance(NMR)curve,the study refines the computational method for the equivalent permeability coefficient in the wetting layer during clay rainfall infiltration,and proposes an improved clay Green-Ampt infiltration model that considers the saturated-unsaturated differentiation layer and the dynamic variation of its equivalent permeability coefficient under continuous rainfall conditions.The computational results of the improved model were compared with measured infiltration data,numerical simulations,and predictions from the traditional GA model.The results indicate that the improved model effectively captures the dynamic variation between the transition layer and wetting layer and provides more accurate predictions of wetting front depth in clay,with an accuracy approximately 68.36%higher than that of the traditional GA model.展开更多
The measurement of momentum correlations of identical pions serves as a fundamental tool for probing the space-time properties of a particle-emitting source created in high-energy collisions.Recent experimental result...The measurement of momentum correlations of identical pions serves as a fundamental tool for probing the space-time properties of a particle-emitting source created in high-energy collisions.Recent experimental results have shown that in pp collisions,the size of the one-dimensional primordial source depends on the transverse mass(m_(T))of the hadron pairs,following a common scaling behavior similar to that observed in Pb-Pb collisions.In this study,a systematic analysis of the π-π source and correlation functions was performed using the multiphase transport model(AMPT)to understand the properties of the emitting source created in high-multiplicity pp collisions at√s=13 TeV.The mT-scaling behavior and pion emission source radii measured by the ALICE experiment can be described well by a model with a subnucleon structure.This work sheds new light on the effective size of the π-π emission source and the study of intensity interferometry in small systems using a transport model.展开更多
Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e...Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation method.Results show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative analysis.The wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall stage.Then,macropores benefit the slope stability in the early rainfall but not in the latter.Macropore flow does not occur initially but becomes pronounced with increasing rainfall duration.The equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore flow.Parameter analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows slowly.Finally,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.展开更多
基金financial support from the Joint Funds of the National Nature Science Foundation of China(No.U22A20232)Supported by Open Project Funding of Key Laboratory of Intelligent Health Perception and Ecological Restoration of Rivers and Lakes,Ministry of Education(HGKFZ07)+2 种基金the National Natural Science Foundation of China(No.51978249)Innovation Research Team Project of the Hubei Provincial Department of Science and Technology(2025AFA020)the International Collaborative Research Fund for Young Scholars in the Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes.
文摘The traditional Green-Ampt model does not accurately represent the infiltration behavior of clay soils.Infiltration in clay is influenced by low hydraulic conductivity,strong capillary forces,and a gradual transition zone between saturated and unsaturated zones.These factors often lead to overestimated infiltration rates and underestimated infiltration durations.Therefore,it is necessary to improve the model to better reflect the characteristics of clay infiltration and enhance its predictive accuracy and practical applicability.This study conducts hydraulic characterization tests,one-dimensional soil column rainfall infiltration experiments,and numerical analysis on a representative clay sampled from Wuhan,China,to investigate infiltration behaviors under varying rainfall intensities and initial moisture conditions.The study reveals that the proportion of the transition layer within the wetting layer decreases with increasing wetting front depth,following a power-law function.Under the same initial moisture content,this proportion tends to converge to a stable value regardless of rainfall intensity.In contrast,under the same rainfall intensity,a higher initial moisture content leads to a larger proportion of the transition layer at a given wetting front depth.Based on the NMR curve,the unsaturated permeability coefficients corresponding to different volumetric water contents of clay can be obtained quickly,accurately,and at low cost.By utilizing the unsaturated permeability coefficient prediction model based on the nuclear magnetic resonance(NMR)curve,the study refines the computational method for the equivalent permeability coefficient in the wetting layer during clay rainfall infiltration,and proposes an improved clay Green-Ampt infiltration model that considers the saturated-unsaturated differentiation layer and the dynamic variation of its equivalent permeability coefficient under continuous rainfall conditions.The computational results of the improved model were compared with measured infiltration data,numerical simulations,and predictions from the traditional GA model.The results indicate that the improved model effectively captures the dynamic variation between the transition layer and wetting layer and provides more accurate predictions of wetting front depth in clay,with an accuracy approximately 68.36%higher than that of the traditional GA model.
基金the National Natural Science Foundation of China(Nos.12061141008,12147101,and 12322508)the Science and Technology Commission of Shanghai Municipality(23590780100)+1 种基金LZ acknowledges the support of the Fundamental Research Funds for the Central UniversitiesChina University of Geosciences(Wuhan),with No.G1323523064.
文摘The measurement of momentum correlations of identical pions serves as a fundamental tool for probing the space-time properties of a particle-emitting source created in high-energy collisions.Recent experimental results have shown that in pp collisions,the size of the one-dimensional primordial source depends on the transverse mass(m_(T))of the hadron pairs,following a common scaling behavior similar to that observed in Pb-Pb collisions.In this study,a systematic analysis of the π-π source and correlation functions was performed using the multiphase transport model(AMPT)to understand the properties of the emitting source created in high-multiplicity pp collisions at√s=13 TeV.The mT-scaling behavior and pion emission source radii measured by the ALICE experiment can be described well by a model with a subnucleon structure.This work sheds new light on the effective size of the π-π emission source and the study of intensity interferometry in small systems using a transport model.
基金funded by the Natural Science Foundation of Fujian Province(Grant No.2023J011133)。
文摘Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation method.Results show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative analysis.The wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall stage.Then,macropores benefit the slope stability in the early rainfall but not in the latter.Macropore flow does not occur initially but becomes pronounced with increasing rainfall duration.The equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore flow.Parameter analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows slowly.Finally,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.
