Water Sand Research Articles

The Numerical Investigation of Solid–Liquid Two-Phase Flow Characteristics Inside and Outside a Newly Designed 3D Sediment Trap

Sediment transport serves as a link for material exchange between land and sea. Using sediment traps, we can observe the capture and transport processes of sediments. Based on the sediment particle size distribution characteristics in Jiaozhou Bay, this paper analyzes the influence of a newly designed 3D sediment trap on the water–sand two-phase flow process inside and outside a trap device during its operation. Meanwhile, under a certain concentration condition, a numerical formula model is researched and proposed to evaluate the impact of the device’s structure, the environmental flow speed, and the particle size on particle capture efficiency. This model is based on the CFD-DPM coupling in Fluent 2021R1 software, and the particle filtration process is solved using a combination of porous media and UDF functions. Finally, by analyzing the distribution of sediment movement in the fluid domain, two concepts, namely the percentage of particles entering the tube and the effective capture rate, are proposed. Suggestions for optimizing the structure of the trap are put forward to achieve optimal capture effects.

Monitoring Preferential Flow of Water in Sand Using Thermoacoustics Wave Imaging

AbstractAccurate predictions of fluid flow, mass transport, and reaction rates critically impact the efficiency and reliability of subsurface exploration and sustainable use of subsurface resources. Quantitative dynamical sensing and imaging can play a pivotal role in the ability to make such predictions. Geophysical thermoacoustic technology has the potential to provide the aforementioned capabilities, since it builds upon the principle that electromagnetic and mechanical wave fields can be coupled through a thermodynamic process. In this letter, we present laboratory experiments featuring the efficacy of thermoacoustic imaging in the monitoring of preferential flow of water in porous media. Our laboratory experimental equipment can be readily packaged in a form factor that fits in a borehole, and the use of multiple acoustic transducers—which can be combined with volumetric coding techniques—has the potential to provide quasi‐real‐time imaging (0.5 Hz video rate) of regions in close proximity (a few meters) of an open field well.

Study on Plugging Material and Plugging Mechanism of Crude Oil Sand Water Filter Pipe

In order to develop the biological self-cleaning anti-clogging high-permeability sand filter tube, it is very important to analyze the plugging material and plugging mechanism of crude oil sand water filter. Under laboratory conditions, based on vacuum drying, condensation reflux, chromatographic separation, and other technologies, the plugging components were preliminarily analyzed. The plugging components were analyzed via XRD, infrared analysis, 1H NMR, and 13C NMR. Through analysis and testing, XRD results showed that the solid compositions were clay and sand grains. Meanwhile, the infrared analysis, 1H NMR, and 13C NMR demonstrated that the main components of the plug are asphaltene crude oil, and the proportion of aromatic components and saturated components is close.

Gastropods Species Associated with Seagrass Ecosystems in Pasir Putih, Manokwari

Gastropods are one of the classes of mollusks that associate well with seagrass ecosystems. The waters of Pasir Putih are included in a coastal area where many types of gastropods are found in seagrass ecosystems. However, not all types of gastropods in seagrass beds in this region are well known. For this reason, this study aims to determine the types of gastropods associated with seagrass ecosystems in the waters of Pasir Putih, Manokwari. But specifically the objectives of this study are divided into 3, knowing the types of gastropods, seagrass species and the association of gastropods with seagrass in Pasir Putih Waters, Manokwari. In sampling, the quadratic transect method was used, drawn perpendicularly from the shore towards the shore. Physical parameters of water chemistry were observed in situ, this data collection method used was descriptive method. Based on the results of the identification that has been done, that there are 115 individuals, 42 species and 15 families that exist in the White Sand Waters, Manokwari. Four seagrass species were found, namely Cymodocea rotundata, Halodule pinifolia, Halophila ovalis, and Syringodium isoetifolium.

Experimental investigation of viscous oil–water–sand flow in horizontal pipes: Flow patterns and pressure gradient

Fluid production from unconsolidated reservoirs often leads in sand production, which poses a number of issues. Sand deposition in flowlines can result in significant pressure dips, pipe and facility damage, and obstructions that decrease productivity. More research is needed to understand the movement and deposition of sand in oil–water–sand (O–W–S) fluxes. This article focuses on O–W–S flows in a 6-meter-long horizontal pipe with an inner diameter of 0.0381 m. The study looks at the flow behavior of high viscosity oil–water (O–W), water–sand (W–S), and oil–water–sand (O–W–S) flows. Experiments were carried out at 250 psig pressure in a laboratory flow test facility using various heavy synthetic oils (viscosities ranging from 3500 cP to 7500 cP at 25°C) and tap water. The sand concentration varied from 1% to 10%, with an average sand particle diameter of 145 μm and material density of 2630 kg/m3. Water cuts ranged from 0.0 to 1.0. The experimental results revealed a minor change in pressure gradient between (O–W) and (O–W–S) flows. However, increasing the sand concentration in (O–W–S) flow resulted in higher pressure losses. The reduction factor of pressure gradient indicated that the highest decrease in pressure drop occurred at higher superficial oil velocities. Furthermore, a direct relationship was observed between the reduction factor and the decrease in water cut. The results also showed that the minimum required transportation velocity for sand slurry decreased with increasing superficial oil velocity, while the minimum transportation condition increased with higher sand concentration. The comparison between the expected pressure gradient from Bannwart and McKibben et al. and the actual experimental data demonstrated significant accuracy for the oil viscosities and superficial oil velocities used in the study.

Study of the Catastrophic Process of Water–Sand Inrush in a Deep Buried Stope with Thin Bedrock

Taking the 14,030 panel of Zhaogu No. 2 coal mine as its research object, this paper studies the evolution characteristics of the developing height, propagation track and caving arch shape of water-flowing fractures under the influence of thick alluvium by utilizing a physical experiment, theoretical analysis and field investigation. The results show that the height and limit span of the water-flowing fracture zone experience four stages, which include the initial stage, slow-increasing stage, sudden-increasing stage and stable-increasing stage. With the increase in the mining influence range, the shape of the water-flowing fracture in overburden under the influence of thick alluvium is gradually formed. The water in the thick alluvium and the water in the upper phreatic aquifer of the bedrock penetrate each other to form a concentrated danger zone, and the expansion track of the mining water-flowing fracture connects the hydraulic connection between the upper concentrated danger zone of overburden and the panel of No. 2’s first coal seam. A large amount of water mixed with sandstone flows into the fracture surface of the bedrock’s broken rock block through the water-flowing fracture, leading to the instability of the load-bearing structure composed of the thick alluvium caving arch and the towering roof beam, which illustrates the whole process of water–sand inrush accidents in thin bedrock stope with deep thick alluvium.

Numerical and experimental study on vortex optimization in the forebay of a Sandy River

Because the movement of water and sediment is complex, the flow pattern in a forebay can be disordered, which can significantly affect the pumping efficiency of a pump station. Using a pumping station in Ningxia, a multiphase water–sand flow model is built based on field measurements and practical engineering. The vortex flow pattern and the cause of sediment deposition are analyzed by numerical simulations and experiments. Furthermore, 36 rectification measures are proposed to improve the vortex flow pattern and sediment deposition in the forebay. The results show that various rectification measures can correct the flow pattern disorder in the horizontal section of the forebay at different angles. However, the correction effect is not obvious in the slope section. For the first time, a combination plan of adding plates to the back wall of the pumping station is proposed. This strategy not only improves the vortex area of the horizontal section of the forebay but also diverts the vortices of the slope section, reducing the vortex range and the sediment content. At the same time, the flow velocity uniformity of the inlet section of the combined optimal solution increases by 19.22%, and the shear angle decreases by 8.81°. The combination of numerical simulation and experimental analysis demonstrates the accuracy of the combined plan, corrects the flow pattern in the forebay, and reduces the sediment content.

Sanitary and parasitological condition of environmental objects of the Astrakhan Region

The article presents the sanitary-parasitological state of environmental objects of the Astrakhan region for 2022. In 2022, 6246 samples taken from various environmental objects were examined, the number of samples that did not meet sanitary-parasitological indicators was 0.7 % (41 samples): toxocar eggs — 17 samples, strongylid larvae (mobile and immobile) — 19 samples, ascarid eggs (fertilized) — 5 samples. The largest number of samples accounted for flushing from solid household surfaces — 76.7 % (4790 samples), of which only 0.02 % (1 sample) revealed ascaris eggs (fertilized). The second place in the number of samples studied belongs to samples of water bodies — 8.1 % (505 samples), of which 2.2 % (11 samples) did not meet sanitary and parasitological indicators: strongylid larvae (mobile and immobile) were detected — 8 samples, toxocar eggs — 2 samples and ascaris — 1 sample. Samples of food products and food raw materials made up almost the same number of samples — 8.1 % (503 samples), of which 3.2 % (16 samples) were samples that did not meet parasitological indicators. As a result of the work done, the results were obtained: the parasitic contamination of environmental objects in 2023 remains very unfavorable. Contamination of water of surface reservoirs, soil and sand with helminthiasis pathogens may indicate that these objects were contaminated with feces of infected animals and humans, or about the fact of accidents on the sewer network and the likely ingress of helminthiasis pathogens from outside. The presence of parasites in food samples may indicate contamination of the water used for irrigation or contamination of the soil with the feces of infected animals and humans.

Contribution of Climate Change and Human Activities to Runoff and Sediment Discharge Changes Based on Budyko Theory and Water–Sediment Relationships during 1960–2019 in the Taohe River Basin, China

Variations in runoff and sediment discharge are important characteristic variables for revealing the coupled effects of climate change (including both the natural variability of climate and anthropogenic climate change) and human activities (including soil and water conservation measures, land use changes, and hydraulic engineering construction). Based on the meteorological data from 19 meteorological stations and the hydrological data from the watershed control station of Hongqi Station, the temporal and spatial evolution of runoff and sediment discharge and the water–sand relationship were analyzed, and the response mechanisms of runoff and sediment discharge changes were clarified using Mikhail Budyko’s theory and other qualitative and quantitative methods. The results determined that: (1) The runoff and sediment discharge showed significant downward trends, with linear change rates of −0.28 × 108 m3/a and −46.10 × 104 t/a, respectively. The change points of the runoff and sediment discharge occurred in 1987 and 1996, respectively. (2) The spatial distribution of water and sediment was different, and the upper and middle reaches produced water, while the downstream produced sediment. (3) Comparing potential evapotranspiration and rainfall based on Budyko theory and the regression relationship, runoff is more closely related to rainfall, and runoff changes are more affected by it. The change in sediment discharge is most closely related to sediment concentration, followed by rainfall and potential evaporation. (4) The contribution rates of runoff and sediment discharge changes influenced by climate change were 24% and 3%, respectively, and the contribution rates by human activities were 76% and 97%, respectively. Human activities, including soil and water conservation measures, land use changes, and hydraulic engineering construction were the main influencing factors, and the impacts of human activities increased from 1960 to 2019. The research results are of great significance for erosion control and ecological restoration in the Tao River Basin under the conditions of the changing environment.

Study of Water–Sand Inrush through a Vertical Karst Conduit Uncovered through Tunnel Excavation

The existence of karst compromises the safety of underground engineering, especially during tunnel excavations. Karst conduits are uncovered through tunnel excavations, which may lead to a water–sand inrush disaster. Taking a vertical karst conduit as an example, the process of water–sand inrush through a karst conduit could be viewed as being similar to the process whereby a water–sand mixture flows through the discharge opening of a storage bin. In this study, based on force analysis of a non-aqueous sand body above a karst conduit, the limiting diameter of the karst conduit under force equilibrium was obtained. Considering the effect of water on aqueous sand bodies, the criterion of water–sand inrush was established. We aimed to study water–sand migration and inrush through vertical karst conduits in order to obtain the distribution of the water pressure near a vertical karst conduit, and to explore the relationship between the conduit size, water pressure, and water–sand flow rate; therefore, a simulated testing system for analyzing water–sand inrush through a vertical karst conduit was developed. When the water pressure in the testing chamber was close to the critical head pressure of the water–sand inrush, the water–sand inrush exhibited a pattern of instability—migration—deposition—stability. When the water pressure in the testing chamber exceeded the critical head pressure, the water–sand flow increased first and then stabilized over time. With the increase in the set values of the water pressure and conduit size, the steady flow of the water–sand mixture increased gradually. When the karst conduit was opened suddenly, the actual water pressure in the testing chamber decreased significantly, due to the water–sand mixture flowing out of the testing chamber and the water supply lagging behind. With the stabilization of the water–sand flow, the actual water pressure gradually tended towards stability, but it was still lower than the initial set water pressure. When the karst conduit was opened, the values of the water pressure monitored by the pore pressure gauges all clearly decreased. With the stabilization of the water–sand flow, the water pressure gradually became stable. With the increase in the distance between the pore pressure sensor and the karst conduit, the water pressure values all increased gradually. These test results are significant for further studies of the formation mechanisms of water–sand inrush through vertical karst conduits.

Increasing performance efficiency of reconstructed oil fields

In the oil-gathering stations of most OGPDs, oil water sand clay mixtures that enter the settling equipment after passing through the separators are initially separated and collected in appropriate tanks. Prior to the production of commercial oil, more labor and energy is utilized to separate water and sand-clay mixtures from oil. Tanks are quickly contaminated with bottom sediments consisting of sand-clay and cleaning of them is difficult. Mixtures of sand-clay-water from settler, formation water from oil tanksa are drained into open oil traps, as a result, the environment is polluted with oil wastes and oil losses occur. It is more efficient to use a horizontal oil and gas separator to overcome shortcomings identified in the reconstruction of the tank farm with a capacity of more than 1.500 m3/day. Sand-clay separator should be installed at the inlet of it to protect the separator and tanks from sand-clay mixed sediments. Sand-clay separators should be installed inside the overflow tanks for better separation of formation water and sand-clay mixtures from oil, oil suspensions and sand-clay mixtures from water in formation water storage tanks. In order to reduce evaporation losses in the tanks, an auxiliary palte should be used under the PSV and the gas phase of the technological tanks and commercial oil tanks should be connected via pipes.

Evolution of the Chenglingji–Datong Channel in the Middle and Lower Reaches of the Yangtze River and Its Drivers

In recent years, the water–sand composition of the Yangtze River channel has changed due to the influence of human factors, especially the construction of water reservoirs such as the Three Gorges Project. Changing water–sand conditions have a long-term impact on the shaping of the river channel morphology in the middle and lower reaches of the Yangtze River, and the erosion retreat of local river sections has caused great harm to embankment projects. This paper focuses on the river evolution mechanism of the river channel from Chenglingji to Datong in the middle and lower reaches of the Yangtze River over the past 31 years. Landsat remote sensing images from 1989–2019 were used to extract and interpret water bodies, river shorelines, and central bars in the study area using the Modified Normalized Difference Water Index (MNDWI) combined with visual interpretation. We used near analysis to study the morphological evolution characteristics of the river, the channel, and selected typical river reaches for comparative analysis. We found out that the overall change in river morphology between 1989 and 2019 was small in the horizontal direction, but the local area changed significantly. Considerable scouring occurred in the vertical direction. Combining hydrological and meteorological data, we investigated the effects of the Three Gorges Dam, instream sand mining, boundary conditions, vegetation cover on both sides of the riverbanks, and aspects of storm flooding in the watershed on the evolution of the river. The study indicated that the geological conditions on both sides of the river, the implementation of the bank protection project, and the improvement of vegetation cover on both sides of the river have made the riverbanks more resistant to scouring. However, heavy rainfall floods, the operation of the Three Gorges Reservoir, and sand mining activities in the river channel make the river channel more susceptible to scouring. Based on the calculation of the slope change rate of the accumulated volume, it was found that the runoff is mainly influenced by precipitations, while the sand transport is mainly affected by human activities. This study shows that natural and anthropogenic activities affect the equilibrium state of the river’s water and sediment to varying degree.

Study on Prevention and Control Measures of Water–Sand Inrushes Based on Adaptive Adjustment of Mined Thickness

There have been frequent occurrences of water–sand inrushes in underground mines due to irregular mining activities under thick loose gravel layers. The morphological development characteristics of the caving zone and the changes in the geological conditionsin the working face under a thick loose sedimentlayerof the Pingan Coal Mine have been studied. The empirical formula and numerical simulations are carried out to explore the effect of different thicknesses of the bedrock on the height of the caving zoneand mining thickness. The method of solving the water-sand inrush of the fully mechanized caving face by adjusting the mining thickness was proposed. The results indicate that there is a linear relationshipbetween the height of the caving zone and the mined thickness. The caving height ratio decreases with an increase in the mined thickness and the correlation can be described by a power function. The maximum allowable height of the caving zone and mined thickness are determined based on the thickness of the bedrockand the changed tendency of the caving height ratio. This provides a mean to control the stability of the sand layer on the roof of the working face by adjusting the mined thickness of coal. The method has been applied in the Pingan mine to prevent water-sand inrushes successfully.

Phase Distribution Measurement of Liquid–Solid Media Using Multimode Ultrasound

Ultrasound tomography (UT) is an emerging technique for phase distribution measurement in industrial multiphase flow monitoring. A multimode UT combining the ultrasound transmission and reflection modes is proposed to measure stratified phase distribution and sound speed of liquid–solid mixtures in the horizontal pipe. First, the acoustic attenuation is used to reconstruct the phase distribution with a modified matrix regularization algorithm, and the time-of-flight (TOF) of ultrasound is used to extract the boundary of multiphase layers with the weight Akaike information criterion algorithm. Second, a wavelet fusion method based on the principal component averaging is proposed to fuse the reconstruction images of UT transmission and reflection. Third, numerical investigations are carried out to validate the feasibility of the proposed method. According to the quantitative indexes, the proposed method can effectively reconstruct the phase distribution of multiphase media. Finally, an experimental test pipeline Section is established, and sand–water and oil–water–sand liquid–solid media are investigated. The minimum relative error (RE) and the maximum correlation coefficient (CC) of experimental fusion results can reach 0.33 and 0.94, respectively, and the average measurement error (ME) of the layer height is 3.80%.

Bioinspired Dynamic Antifouling of Oil‐Water Separation Membrane by Bubble‐Mediated Shape Morphing

AbstractOil–water separation membranes easily fail to oil foulants with low surface energy and high viscosity, which severely limits these membranes’ applications in treating oily wastewater. Herein, an oil–water separation membrane by bioinspired bubble‐mediated antifouling strategy is fabricated via growing hierarchical cobalt phosphide arrays on stainless steel mesh. The as‐prepared membrane is superhydrophilic/superaerophobic and electrocatalytic for hydrogen evolution under water, which helps to rapidly generate and release abundant microbubbles surrounding the oil‐fouled region on the membrane. These microbubbles can spontaneously coalesce with the oil foulants to increase their buoyancy and warp their interface tension by morphing the oil shape. And this spontaneous coalescence also increases the kinetic energy of oil foulants resulting from the decreased bubbles’ interface energy and potential energy. The synergy of the warped interface tension, increased buoyancy, and kinetic energy drives the efficiently dynamic antifouling of this membrane. This dynamic antifouling even can remove some solid sediment such as oily sand particles that causes more serious fouling of the membrane. Thus, this membrane maintains high flux (>11920 L m−2 h−1 bar−1) in the long‐term separation of oil–water and oil–sand–water emulsions by dynamically recovering the decayed flux on demand, which exhibits great potential in treating industrial oily wastewater.

A State-Dependent Hypoplastic Bounding Surface Model for Gassy Sand

As a kind of partially saturated soil often containing dissolved gas with a high degree of saturation (S > 85%), gassy sand sediment widely exists in the marine environment all over the world. Due to the effect of gas dissolution and exsolution on the pore fluid compressibility, its stress–strain and pore pressure responses are quite different from those of common saturated and unsaturated soils when subjected to undrained loading. Since almost all the gas bubbles are occluded in the pore water of offshore gassy sand, the matric suction may be neglected, and an undrained constitutive model for gassy sand is developed based on the existing hypoplastic bounding surface model for saturated sand. Both Boyle’s and Henry’s laws are employed in the model to characterize the equilibrium behavior of the gas compressibility and solubility, and then the equivalent compressibility coefficient of the pore fluid is obtained. To avoid unrealistic volumetric expansion, the concepts of the critical state and state-dependent dilatancy stress ratio are incorporated to describe its ultimate shear strength and dilatancy characteristics, respectively. Finally, the triaxial undrained test results on gas-charged sand from Hangzhou Bay are analyzed at three initial saturation degrees of 85%, 90%, and 100%, and two effective confining pressures of 50 kPa and 200 kPa. Moreover, carbon dioxide (CO2) was selected in the test, and the samples were loose with a relative density of 30%. It is noted that a good agreement is achieved between the simulation results and the experimental data, including the influence of gas content and confining pressure on the shear dilatancy and the mean effective stress increase at the beginning of the effective stress path, among others.

Two-phase MPM modelling of debris flow impact against dual rigid barriers

Multiple barriers are usually installed to effectively mitigate large-volume debris flows. Existing multiple-barrier design recommendations ignore the effects of solid–fluid interaction and may cause uncertainties in estimating the flow impact force on subsequent barriers. In this study, a fully coupled, two-layer, two-phase material point method with an incompressible fluid phase is implemented and validated using the experimental results of dry sand, water and sand–water mixture flows impacting on rigid barriers. Numerical parametric study is carried out using the validated model to investigate the effects of Froude number (Fr) and barrier spacing on second barrier impact force. A debris flow volume of 500 m3 is modelled, with the Fr ranging from 2 to 6; these are values relevant to the gentle and steep terrains in Hong Kong. Simulation results show the importance of changes in fluidisation ratio, which is the ratio of basal pore fluid pressure and total stress. The debris flow, after impacting the first barrier, overflows and lands on the slope between the two barriers. The fluidisation ratio of debris flow after landing increases by up to 30%, leading to an increase of impact velocity at the second barrier by up to 80%. Consequently, the impact force of debris flows on the second barrier is underestimated by up to 50% compared with existing design guidelines. This implies that neglecting the fluidisation ratio may lead to non-conservative design of multiple barriers.

The effect of VC content on the scouring erosion resistance of tool steels

This work investigates the effect of vanadium carbide (VC) content and bulk hardness on the low angle impingement/scouring erosion of tool steels. Five grades of CPM xV (x = 1, 3, 9, 10, and 15) tool steels have been studied using a Coriolis erosion tester with a slurry of 10 wt% AFS 50–70 silica sand in water. The results showed that the scouring erosion resistance of the steels increases with increase in VC volume fraction and the increase is much more rapid when the volume fractions of VC are greater than ∼12%. On the other hand, the erosion resistance is mostly independent of material hardness. Wear scars were examined using scanning electron microscopy and laser profilometry. It was found that the standout wear protection effect of the fine VC carbides became more pronounced in steels with VC volume fractions higher than ∼12%. In these steels, the contribution of the microcutting mechanism decreased drastically with increase in VC volume fraction, with the grooving depth being reduced by about 4 times in CPM 15V as compared with the steel containing the lowest VC volume fraction (CPM 1V).

Overburden stress evolution characteristics and prediction of disasters with across-gully mining

The coal water co-mining of shallow coal seams in the loess gully area of Northern Shaanxi is affected by the coupling effect of overburden rock structure and topography. The development characteristics of mining fracture are complex and can induce mining and environmental disasters. To predict the disaster formation, taking the 113101 working face of the Kunyuan Coal Mine as the engineering background, numerical simulation, physical similarity simulation experiment, and theoretical analysis methods were used to analyze the mining gully of a shallow coal seam in a loess gully area. Based on the dynamic evolution characteristics of stress at different locations, the formation positions, dynamic development, and evolution processes of various fractures were studied; disaster-causing mechanisms were revealed and comprehensive methods were proposed. The results showed that in across-gully mining, the maximum horizontal compressive stress at the bottom of Gully No. 2 was approximately 20.00 MPa, the maximum horizontal tensile stress of the reverse slope section was approximately 1.50 MPa, the width of the F5 fracture of Gully No. 2 was 46.00 cm, and the elevation difference was up to 52.00 cm. The working face across-gully mining formed tensile fractures in most areas, collapsed fractures at the gully bottom, and extruded fractures in the reverse slope section. The fracture at the gully bottom could easily induce water–sand inrush and roof caving and supports crushing. The slope fracture could also induce a gully-induced landslide. According to the mechanisms and distribution areas of fracture disasters, the disaster areas were divided into water–sand inrush areas at the gully bottom, roof caving and supports crushing areas at the gully bottom and at the base of the slope section, and landslide areas at the upper part of the slope section and reverse slope section. Appropriate prevention and control measures were proposed, such as the upstream interception of surface water, slope reinforcement in the middle and upper part of the downhill section, artificial precracking of the roof in the middle and upper part of the downhill section, and grouting reinforcement at the gully bottom and slope toe of the downhill section. These measures were proven to effectively guarantee the safe and efficient mining efficiency of the working face.

Study on Barriers of Water Salt Transfers in Earthen Sites by Plastic-Coated Sand

Under the action of unidirectional water migration, museum soil sites generally encounter erosion through dry cracking, salt enrichment, etc. In this paper, the earthen site of the Terra Cotta Warriors Museum of the First Emperor of Qin was used as the research object, and the “hydrophobic” property of coated sand was proposed to prevent water migration and salt accumulation. Through the soil column experiment of water salt migration and the HYDRUS software numerical simulation, the water salt migration law of the soil in the heritage site under different conditions and the characteristics of water and salt resistance of plastic-coated sand were studied. The results showed that the salt damage on the earthen ruins was mainly due to the horizontal and vertical migration of water and salt in soil. After embedding the coated sand layer into the soil environment under the earthen site, the vertical and horizontal migration of water and salt in the soil can be completely prevented due to precipitation and groundwater. The coated sand protection technology and method proposed in this paper use materials similar to those of the earthen, and provide a feasible method for the protection of cultural relics in our country.