A sandbox experiment model was designed to simulate how differences in rock strength and gravity between two blocks can influence the formation characteristics of thrusts. In the experiment the compression was from on...A sandbox experiment model was designed to simulate how differences in rock strength and gravity between two blocks can influence the formation characteristics of thrusts. In the experiment the compression was from one direction with basement shortening and the initial surfaces of the model were oblique. The results show that if the initial surface was horizontal or the slope angle was smaller than 7°, the compression induced two groups of thrusts with opposite dip orientations. If the slope angle of the initial surface was greater than 7°, the compression induced only one group of thrusts with a dip orientation contrary to the original compression direction. This result is similar to the actual section of a collision zone between two continental blocks. By applying stress analysis, rock strength is shown to be an important factor in deformation. As other boundary conditions are changeless, it is the change of gravitational potential energy that leads to different deformation styles.展开更多
Studying contaminant transport in the capillary fringe(CF),a crucial part of the vadose zone,offers insights into the mechanisms controlling pollution in soils and groundwater aquifers.This paper investigated contamin...Studying contaminant transport in the capillary fringe(CF),a crucial part of the vadose zone,offers insights into the mechanisms controlling pollution in soils and groundwater aquifers.This paper investigated contaminant transport in the CF by continuously injecting a conservative tracer(NaCl)and graphene oxide nanoparticle(GONP),an adsorptive contaminant,into a sandbox.After entering the CF from the unsaturated zone,both NaCl and GONP underwent lateral transport.The breakthrough curves(BTCs)for NaCl and GONP were derived from water samples collected at predetermined sampling holes.Subsequently,contaminant transport in the CF was modeled using a one-dimensionaletwo-dimensional(1D-2D)coupled hydrodynamic model.This model incorporated lateral dispersivity(aL=1.198 cm)and longitudinal dispersivity(aT=0.286 cm),calculated using a point-by-point method.The hydrodynamic dispersion coefficients obtained were then applied to the Brooks and Corey(BC)and the van Genuchten(VG)parametric models.The BC model more accurately simulated the NaCl migration compared to the VG model,leading to its application in simulating GONP transport in the CF.However,the simulated BTCs for GONP showed a lag behind the measured data,especially at high ionic strengths.This discrepancy was attributed to the variable adsorption partition coefficient of GONP under different ionic conditions.During the experiment,GONP adsorption onto the porous media's surface altered the capillary dynamics,notably increasing capillary rise height,decreasing seepage velocity,and reducing GONP dispersion.Therefore,it is necessary to consider the adsorption capacity of the contaminants in order to accurately assess their transport within the vadose zone.展开更多
基金This paper is supported by the project IGCP411(3-3-02-24) .
文摘A sandbox experiment model was designed to simulate how differences in rock strength and gravity between two blocks can influence the formation characteristics of thrusts. In the experiment the compression was from one direction with basement shortening and the initial surfaces of the model were oblique. The results show that if the initial surface was horizontal or the slope angle was smaller than 7°, the compression induced two groups of thrusts with opposite dip orientations. If the slope angle of the initial surface was greater than 7°, the compression induced only one group of thrusts with a dip orientation contrary to the original compression direction. This result is similar to the actual section of a collision zone between two continental blocks. By applying stress analysis, rock strength is shown to be an important factor in deformation. As other boundary conditions are changeless, it is the change of gravitational potential energy that leads to different deformation styles.
基金funded by the Yangzhou Talent Program“LvYangJingFeng”(YZLYJFJH2022YXBS124).
文摘Studying contaminant transport in the capillary fringe(CF),a crucial part of the vadose zone,offers insights into the mechanisms controlling pollution in soils and groundwater aquifers.This paper investigated contaminant transport in the CF by continuously injecting a conservative tracer(NaCl)and graphene oxide nanoparticle(GONP),an adsorptive contaminant,into a sandbox.After entering the CF from the unsaturated zone,both NaCl and GONP underwent lateral transport.The breakthrough curves(BTCs)for NaCl and GONP were derived from water samples collected at predetermined sampling holes.Subsequently,contaminant transport in the CF was modeled using a one-dimensionaletwo-dimensional(1D-2D)coupled hydrodynamic model.This model incorporated lateral dispersivity(aL=1.198 cm)and longitudinal dispersivity(aT=0.286 cm),calculated using a point-by-point method.The hydrodynamic dispersion coefficients obtained were then applied to the Brooks and Corey(BC)and the van Genuchten(VG)parametric models.The BC model more accurately simulated the NaCl migration compared to the VG model,leading to its application in simulating GONP transport in the CF.However,the simulated BTCs for GONP showed a lag behind the measured data,especially at high ionic strengths.This discrepancy was attributed to the variable adsorption partition coefficient of GONP under different ionic conditions.During the experiment,GONP adsorption onto the porous media's surface altered the capillary dynamics,notably increasing capillary rise height,decreasing seepage velocity,and reducing GONP dispersion.Therefore,it is necessary to consider the adsorption capacity of the contaminants in order to accurately assess their transport within the vadose zone.
