Side Slope Research Articles

A Case Study: Shear Interface Testing of a Constructed Geosynthetic Barrier

Since geosynthetic interfaces often serve as a weak plane on which sliding may occur, shear strengths of these interfaces need to be carefully assessed. In this case study, geosynthetic and soil samples were exhumed from the base and side slope of a constructed facility to generate site specific data. The importance of using representative materials and performing the shear interface testing under conditions similar to those expected in the field are discussed. Once the test data was available, they were used in a stability analysis software package to determine the Factor of Safety (FoS) of the barrier system. Lastly, to illustrate the risk of using literature shear strengths parameters without confirming them during construction, the FoS using actual shear strengths will be compared to the design FoS which used literature shear strengths.

Effects of ratchet surfaces on inclined thermal convection

The influence of ratchets on inclined convection is explored within a rectangular cell (aspect ratio Γx=1 and Γy=0.25) by experiments and simulations. Measurements are conducted over a wide range of tilting angles (0.056≤β≤π/2 rad) at a constant Prandtl number (Pr=4.3) and Rayleigh number (Ra=5.7×109). We found that the arrangement of ratchets on the conducting plate determines the dynamics of inclined convection, i.e., when the large scale circulation (LSC) flows along the smaller slopes of the ratchets (case A), the change of the heat transport efficiency is smaller than 5% as the tilting angle increases from 0 to 4π/9 rad; when the LSC moves toward the steeper slope side of the ratchets (case B), the heat transport efficiency decreases rapidly with the tilting angle larger than blue π/9 rad. Through the analysis of the flow properties, we give a physical explanation for the observations. As the tilting angle increases, the heat carrier gradually changes from the thermal plumes to the LSC, resulting in different dynamical behavior. In addition, the distribution of the local heat transport also validates the explanation quantitatively. The present work gives insight for the controlling inclined convection using the asymmetric ratchet structures.

Technology of an open pit refinement under limit stability of sides

Purpose. To establish the feasibility of refining deep open-pit mines below the boundary of the use of combined motor-conveyor transport with an increased slope angles of the pit walls using the developed transport unit for reloading rocks to overlying horizons during the reactivation of pillars under transport berms. Methodology. Preparation of a digital block model of the deposit, the elaboration of 3D geomechanical models for the dynamics of mining, 2D and 3D numerical simulation of the rock stress-strain state of the outcrops of opencast workings, mathematical modeling of stepwise ore reserves and mining schedule, patent research and feasibility study. Findings. It is advisable to carry out mining in terms of the marginal rock state with an increase in the slope of the pit sides below the limit of application of the cyclic and continuous method in ultra-deep open pits. Such design of pit sides is achieved when benches are mined from top to bottom within the boundaries of steeply inclined layers with the use of inter-bench loaders of the developed designed in the completion zone. Provisions for the selection and feasibility of using the loader in the deep zone are formulated based on demarcation of application zones of cyclic (road transport) and cyclic-flow (combined road-conveyor transport) technologies. Originality. Schematization of the mining operation was performed based on the calculated values of safety factor of sides, which allows increasing the slope angles of the pit walls of even ultra-deep open pits in the completion zone. It was found that with deepening of mining, the zones of potential sliding move away from the loose overburden to lower ore benches closer to the final depth of the Kacharsky open pit (760 m), but the safety factor corresponds to the required value according to the design standards. Practical value. An increase in the slope of the pit walls in the completion zone can be achieved using the developed loading installation, the main difference of which is that it can be moved without dismantling under conditions of reactivation of transport pillars (with an increase in lifting height by 1.54.5 times compared to the known equipment).

Overtopping-Induced breaching process of concrete-faced rockfill dam: A case study of Upper Taum Sauk dam

The back analysis of the dam breaching process based on reported failure case data is of great significance for understanding dam breaching mechanisms and the ability to predict breach flow hydrograph during emergencies. According to the essential information and post-failure investigation report of the Upper Taum Sauk dam, the first pumped storage power station in the United States, the most probable failure mechanism for dam breach is studied. Furthermore, a detailed physically-based numerical model is developed to simulate the overtopping-induced breach process of the concrete-faced rockfill dam (CFRD). Highlights of the model include the establishment of a simulation method of the dam-break flow based on the actual three-dimensional terrain considering the water-retaining characteristics of concrete face slabs, and the times and lengths of failure for each concrete face slab under water load and self-weight, as well as the adoption of different transportation modes for the widely graded rockfill materials. The breach side slope sliding mechanism is considered during the dam breach process. It is worth noting that the hydraulic features of dam-break flow and breach morphology can be well described with a combination of renormalization group (RNG) k-ε turbulence model and volume of fluid (VOF) method. The calculated results of the Upper Taum Sauk dam breaching parameters agree with the measured values, which testify to the rationality of the proposed model. The obtained time-varying dynamic dam breach process of CFRD can be divided into three stages. Moreover, the sensitivity analysis indicated that, the presence and absence of concrete face slabs affect the breach process of the Upper Taum Sauk dam significantly. The performance comparison with the existing dam breach models also verifies the advancement of the detailed physically-based model. Hence, the addressed numerical method can be used as an effective tool for simulating the CFRD breach process.

Numerical Study on Hydrodynamics of Submerged Permeable Breakwater under Impacts of Focused Wave Groups Using a Nonhydrostatic Wave Model

Extreme waves, called rogue waves or freak waves, usually occur unexpectedly and with very large wave heights. In recent years, extreme waves were reported not only in deep ocean waters but also in shallow waters, which threaten the safety and intactness of the coastal regions. To prevent the coastal infrastructures and communities from the devastating power of extreme surges and waves, many coastal defense structures were built along the coastline, i.e., submerged permeable breakwaters. However, the number of studies on the hydrodynamic characteristics of a submerged permeable breakwater under the impact of extreme waves is relatively few. In addition, wave focusing has been widely used to generate extreme waves in the past few decades. Hence, as a necessary supplement to the previous research work, the hydrodynamic performance of a submerged permeable breakwater under the impacts of focused wave groups was numerically studied by using a nonhydrostatic numerical wave model (NHWAVE). The influences of several main factors, such as the incident significant wave height, water depth, wave peak period, porosity of the breakwater (n), and the side slope angle of the breakwater, were considered. It is expected that the results of this study will further strengthen the research on the hydrodynamic characteristics of a submerged permeable breakwater under extreme wave conditions.

Evaluation of Atactic Polypropylene (APP) geomembranes used as liners for salt ponds

This study focused on evaluating the longevity of Atactic Polypropylene (APP) used as a geomembrane (GM) to line ponds that collect runoff water from salt handling facilities. Samples of APP were exhumed from the ponds that have been in service for 6-, 25-, and 44-years and evaluated in the laboratory. Tests were conducted to analyze the surface cracks and textures, tensile properties, puncture resistance, and ability to hold water (permeability). Control tests were conducted with virgin APP GM. Results were compared based on the difference in the age of the APP, location of where the APP samples were obtained within the side slope of the pond (i.e., submerged, and above water level), and orientation of the side slope in relation to the sun (e.g., east, west, north, or south). Based on the field observations and laboratory evaluations, it was determined that exposure to sunlight accelerates the degradation more so than the chemical degradation that occurs due to the salt content within the pond water. The samples exhumed from the north slope (south-facing) had more severe degradation due to high solar radiation energy deposition.

Optimizing embankment structures in a snowy permafrost region of the pan-Arctic based on a coupled numerical model

In pan-Arctic permafrost regions, snow drift may lead to more snow accumulation around the road, which prevents the heat release from the underlying soil in winter and aggravates the permafrost degradation beneath the road. However, the study of snow distribution patterns around the road is insufficient, which makes it difficult to accurately evaluate the long-term stability of the road. To investigate the thermal regime of the road and optimize the road structure in permafrost regions under the effect of snow drift, based on heat transfer and multiphase flow theories, a coupled numerical model is presented. The model includes snow transportation around the embankment, natural convection of air in the crushed-rock layer, and heat conduction in soil and snow layers. The results of model simulation show that an embankment with a height of 4 m leads to heavier snow accumulation on both sides of the embankment in winter compared to an embankment with a height of 3 m, which accelerates permafrost degradation. The full crushed-rock embankment with a height of 3 m can be used to counteract the permafrost degradation caused by snow accumulation to some extent, while the soil temperature beneath the toe of the embankment slope is still noticeably higher. By contrast, when the U-shaped crushed-rock embankment (UCRE) with a height of 3 m and 1:6(vertical: horizontal) side slopes is used, the snow accumulation around the embankment is greatly reduced, the embankment slope delivers better cooling performance. Considering the climate warming at a rate of 0.067 ℃ year−1 in pan-Arctic regions, the thermal stability of the UCRE can still be ensured after 20 years of its construction. These results provide a valuable reference for road construction in pan-Arctic snowy permafrost regions.

Evaluation of the long-term thermal stability of a crushed-rock revetment embankment in pan-Arctic permafrost regions under the effect of snow drift

In the pan-Arctic region, snow drift events usually result in heavy snow accumulations on both sides of road embankment which severely affects the energy exchange process at the embankment slopes and further changes the temperature distribution in the embankment and its subsoil. However, there is a lack of research on the prediction of snow distribution patterns around the embankment, which makes it difficult to accurately assess the impact of snowdrift on the thermal stability of the embankment in permafrost regions, and the embankment structure cannot be reasonably optimized accordingly. Herein, using the theories of two-phase flow and heat transfer, a numerical model is developed to evaluate the long-term thermal stability of embankments with different structures under the effect of snow drift. The results show that snow deposition occurs at the toe of the windward side slope and the whole leeward side of the embankment under the effect of snow drift. If the side slope of the embankment is reduced from 1:2 to 1:5 (vertical:horizontal), the snow accumulations on both sides of the embankment are significantly reduced, and the subsoil refreezes more effectively in cold season. When a crushed-rock revetment embankment (CRRE) with 1:5 side slopes is used, the soil beneath the embankment is sufficiently cooled, the warming of permafrost beneath both sides of the embankment caused by snow accumulation is eliminated, and the temperature distribution in the embankment and subsoil has a good symmetry in warm season. The crushed-rock revetment is thus proved to be an applicable and effective structure to ensure the long-term stability of the embankment in pan-Arctic permafrost regions.

Wearing high-heeled shoes on a side slope makes standing balance unstable

IntroductionMany women wearing high-heeled footwear are at high risk of falls. Past studies have examined the balance on level ground or balance during walking. We measured the standing balance on the ground and side slopes for 18 healthy women. MethodBody sway was evaluated based on the center of pressure (COP) while participants stood on level ground on a side slope. The total locus length as well as rectangular and outer peripheral areas were then measured using a Zebris system. Measurements were compared under bare feet, normal shoe, and high-heeled shoe conditions. ResultsOn level ground, there were no significant differences among the three conditions. On the side slope, the total locus length (TLL), rectangular area (RA) and outer peripheral areas (OPA) were significantly greater for the high-heeled shoes than for the bare feet and normal shoes. Standing on the side slope caused larger body sway than on the level ground, along with a higher risk of falling. DiscussionIn TLL, OPA, and RA, the COP moved outside substantially when participants stood on a slope in high heels than in shoes. High heels were highly unstable for standing on a slope since the ankle joint of one leg is in plantar flexion, the foot is pronated, and the other side is plantarflexed at the ankle with pronation of the foot. ConclusionHigh-heeled shoes significantly alter a person's balance when standing on a side slope, suggesting a high risk of falling.

Slope stabilisation of railway embankments over loose subgrades using deep-mixed columns

An investigation was undertaken into the stability of railway embankment slopes over soft subgrades stabilised by deep-mixed columns (DMCs). Three 1 : 10 scale laboratory embankments were constructed over unreinforced and reinforced subgrade with DMCs in square and triangle patterns. The load–settlement responses of both embankments and columns were measured. The laboratory embankments were then mathematically modelled and the results were compared. After validation, a comprehensive parametric study was carried out to evaluate the factor of safety (FoS) of the embankment side slopes against sliding. Five embankment soil types from poor to high strength, three heights from 1.5 to 10 m and various DMC improvement area ratios from 0 to 65% were considered. The experimental outcomes indicated an increase of nearly 63% in the bearing capacity of both DMC-supported embankments compared with the unreinforced one. Regarding the parametric study, a minimum required FoS of 1.5 was observed for 1.5 m embankments of all soil types stabilised with a 60% improvement ratio. The greatest safety increase was associated with a 1.5 m height embankment with poor soil type, which showed a 36% increase.

Impacts of snow cover on the pattern and velocity of air flow in air convection embankments of sub-Arctic regions

In northern regions, air convection embankment (ACE) has been implemented to mitigate road subsidence caused by permafrost degradation. The seasonal snow cover largely alters the surface energy balance and adversely affects the thermal stability of the road. However, thermal characteristics of a closed ACE and the quantification of their impacts on talik development remain largely unknown, especially in the present and future context of global warming. Here, impacts of snow cover on the pattern and strength of the air circulation were investigated and quantified. Snow cover greatly weakened the cooling effect of the closed ACE side slopes. The pore air velocity of the crushed-rock layer was reduced by half and the mean annual heat flux increased by approximately 1.6 W/m2, in comparison to the snow-free case. Conversely, the U-shape closed ACE had a better cooling performance due to a stronger air convection in winter, which increased heat loss from the snow-free surface of the embankment center. Our simulations suggest that the U-shape ACE embankment is a potential long-term solution to mitigate permafrost thaw over the life service (50 years) of road embankments in sub-arctic regions. The net results of this study are imperative to improve engineered design and road maintenance in cold regions.

Investigating the Influence of Dam-Breach Parameters on Dam-Break Connected Flood Hydrograph

The dam-break connected flood hydrograph properties primarily depend on the breach geometry and the time for the breach to fully develop. Therefore, the prediction of dam’s breach geometry is essential in dam-break studies. To understand the impact of breach parameters on flood peak hydrograph, five of the most common breach prediction methods are implemented in the presented study to estimate the flood hydrographs using 2-dimensional HEC-RAS model. The Ürkmez Dam is chosen as the case study due to the presence of a residential settlement located right at the dam downstream where undesirably any breach of the dam body can have inevitable and dramatical risks on downstream populations and properties. Various levels for reservoir storage are investigated in each method. In order to assess the impact of each breach parameter on the resulting flood hydrographs, sensitivity analysis is carried out. The peak discharge rates and the times to peak for each analyzed scenario are investigated and discussed. Results reveal that Froehlich approach is the most reasonable method for estimating dam-breach parameters as far as exemplified in the Ürkmez Dam case. Furthermore, sensitivity analysis points out that the parameter of the breach side slope has no major influence on the time to peak while having an insignificant impact on the peak discharge. Besides, the study exhibits that both the peak discharge and the time to peak characteristics are highly sensitive to breach time formation parameter. In the light of these targeted findings, the study is aimed to contribute to other relevant research in designating the set of key parameters in experimental or modeling efforts in a way to limit the uncertainty that substantially originates from personal judgment.

Flow over embankment gabion weirs in free flow conditions

In this study, a series of laboratory tests were performed to investigate the effects of side ramp slope, crest length, and porous media properties on the flow regimes, water-surface profiles, discharge coefficients, and energy dissipation in embankment gabion weirs with upstream and downstream slopes. 24 physical models of solid and gabion weirs with three different upstream/downstream slopes (90°, 45° and 26.5°) were created. To investigate the complexity of flow over the porous-fluid interface and through the porous material, three-dimensional (3D) numerical simulations were developed. In numerical simulation, the standard k-ε turbulence model was utilized. A structured mesh domain was used to simulate the physical model. Water surface profiles above the porous weirs were used for comparison between the numerical simulations and measured data. These comparisons helped determine variables in the numerical simulations. Numerical simulation enables visualization of streamlines around and through the gabion weirs. In addition, mean stream wise velocity profiles above and within the porous structures were obtained. Numerical simulations showed that a reduction in the slope of the upstream face leads to an increased curvature of streamlines and the velocity distribution exhibits a non-uniform wavy shape due to the geometrical properties of the weirs. As the velocity profiles move downstream, the velocity distribution within the porous structures were more affected by the presence of the pores. The experimental results show that decreasing upstream slopes, from 90° to 26.5°, leads to decreased discharge coefficients. However, in all cases, gabion weirs lead to greater discharge coefficients than those of similar solid weirs. For milder side slopes, discharge ratios (flow passing through all faces of the gabion weirs over the inlet discharge) decreased nonlinearly. Moreover, with increasing the inlet discharge, relative energy dissipation was reduced up to 45% in gabion weirs.

Lateral Load Capacity and p-Multiplier of Group Piles with Asymmetrical Pile Cap under Seismic Load

Earthquakes are a high-risk natural phenomenon in Indonesia, which is between three tectonic plates: the Eurasian, Pacific, and Indo–Australian plates. This study examines the response of bored piles with asymmetrical pile cap in the Auditorium Building of Brawijaya University to seismic loads, which is still rare to conduct this research. This study assessed based on 3D finite element-numerical approach, where lateral resistance and p-multiplier values compared on the effects of combination lateral loads, pile stiffness, and soil stiffness. The behavior of lateral resistance and deflection group piles with asymmetrical pile cap and single pile with square pile cap gives a good agreement. The side slope of the pile cap can increase the shear zone, increase the lateral resistance, and the most considerable lateral resistance to the lowest occurs in the horizontal direction, opposite the loading direction. In addition, the pile configuration that is not symmetrical gives an increasing p-multiplier value followed by an increasing deflection and the p-multiplier from the 3D finite element method was within the recommended range.

Analysis of Intelligent Monitoring and Early Warning in High Side Slope Areas

As a large amount of excavation, filling and compaction are required during the construction of railroad projects, and slope cutting is also required in special terrain areas, which destroys the original geological environment balance of the soil, and under the influence of environmental and engineering factors, geological disasters such as landslides and collapses are easily induced. In this paper, a scientific method of slope stability discrimination is firstly proposed on the basis of monitoring and early warning. By combining two methods of engineering displacement monitoring and numerical simulation analysis for monitoring and early warning, it circumvents the problem of using a single method with poor accuracy and improves the efficiency of the early warning system. Compared with the traditional monitoring and early warning, this paper proposes the method of linkage early warning, which summarizes the factors that have a great influence on the stability of slope and obtains the corresponding prediction information in advance, and applies the data to the numerical simulation to obtain the stability change of slope, so that the early warning can be released in advance and the countermeasures can be taken to reduce the loss.

Soil Erosion Assessment Using the RUSLE Model, Remote Sensing, and GIS in the Shatt Al-Arab Basin (Iraq-Iran)

In the Shatt Al-Arab basin, soil erosion is a major problem due to the steepness of the terrain and the significant difference in altitude between the upstream and downstream parts of the basin. Vast quantities of soil are moved annually, resulting in massive repercussions including soil degradation, structural damage, biodiversity loss, and productivity reduction in the catchment area, huge sediment load, and the pollution of streams and rivers. Consequently, the assessment of soil erosion risk and geographical distribution is essential for constructing a database for developing effective control strategies. Revised Universal Soil Loss Equation (RUSLE) was combined with Remote Sensing (RS) and Geographic Information System (GIS) in the current work to define the soil erosion hazard map in the Shatt Al-Arab basin. The RUSLE model included various characteristics for soil erosion zonation including rainfall erosivity, soil erodibility, slope length and steepness, land cover and management, and conservation support practices. Annual erosion rates in this study in tons per hectare were: extremely high (more than 50); very high (50 to 16.5); high (16.5 to 2.2); medium (2.2 to 1); and low (1 to 0) ton ha−1year−1 representing 16, 4, 13, 7, and 60 % of the basin’s area, respectively. The high soil loss rates are associated with heavy rainfall, loamy soil predominance, elevated terrains/plateau borders with a steep side slope, and intensive farming. Managers and policymakers may use the results of this study to implement adequate conservation programs to prevent soil erosion or recommend soil conservation acts if development projects are to proceed in places with a high soil erosion risk.

Cost-effective management measures for coastal aquifers affected by saltwater intrusion and climate change.

Sustainable management of natural water resources and food security in the face of changing climate conditions is critical to the livelihood of coastal communities. Increasing inundation and saltwater intrusion (SWI) will likely adversely affect agricultural production and the associated beach access for tourism. This study uses an integrated surface-ground water model to introduce a new approach for retardation of SWI that consists of placing aquifer fill materials along the existing shoreline using Coastal Land Reclamation (CLR). The modeling results suggest that the artificial aquifer materials could be designed to decrease SWI by increasing the infiltration area of coastal precipitation, collecting runoffs from the catchment area, and applying treated wastewater or desalinated brackish water-using coastal wave energy to reduce water treatment costs. The SEAWAT model was applied to verify that it correctly addressed Henry's problem and then applied to the Biscayne aquifer, Florida, USA. In this study, to better inform Coastal Aquifer Management (CAM), we developed four modeling scenarios, namely, Physical Surface Barriers (PSB), including the artificial aquifer widths, permeability, and side slopes and recharge. In the base case scenario without artificial aquifer placement, results show that seawater levels would increase aquifer salinity and displace large amounts of presently available fresh groundwater. More specifically, for the Biscayne aquifer, approximately 0.50% of available fresh groundwater will be lost (that is, 41,192 m3) per km of the width of the aquifer considering the increasing seawater level. Furthermore, the results suggest that placing the PSB aquifer with a smaller permeability of <100 m per day at a width of approximately 615 m increases the available fresh groundwater by approximately 45.20 and 43.90% per km of shoreline, respectively. Similarly, decreasing the slope on the aquifer-ocean side and increasing the aquifer recharge will increase freshwater availability by about 43.90 and 44.50% per km of the aquifer. Finally, placing an aquifer fill along the shallow shoreline increases net revenues to the coastal community through increased agricultural production and possibly tourism that offset fill placement and water treatment costs. This study is useful for integrated management of coastal zones by delaying aquifer salinity, protecting fresh groundwater bodies, increasing agricultural lands, supporting surface water supplies by harvesting rainfall and flash flooding, and desalinating saline water using wave energy. Also, the feasibility of freshwater storage and costs for CAM is achieved in this study.

Large eddy simulation of flow around semi-conical piers vertically mounted on the bed

In this paper, details, and results of three-dimensional numerical modeling of flow around the semi-conical piers vertically mounted on the bed in a channel, are presented. For flow simulation, 3-D Navier–Stokes equations are solved numerically using the finite volume method and large eddy simulation. In this study, the semi-conical piers with different side slope angles ( $$\alpha$$ ) are tested, and the flow around them is compared with the cylindrical reference pier. Flow structures, vortex shedding behind piers, horseshoe vortices, instantaneous and time-averaged flow structures are presented and discussed. Numerical model results show that the semi-conical piers are eventuated remarkable reduction (up to 25%) in downward flow velocity in the upstream side of the piers, and much more reduction (up to 46%) in bed shear stresses in comparison with the cylindrical pier. Moreover, the model results showed some decrease in vortex shedding frequency for the semi-conical piers compared to the cylindrical pier. We report on numerical results of large eddy simulation of the flow around semi-conical piers with different side slopes. This research is significant because of the effect of these piers on the:

Damage Simulation Analysis of Canal Concrete Lining Plates Based on Temperature-Stress-Water Load Coupling

Forming an important component of water conservation infrastructure, canal concrete linings are often subjected to damage to different degrees under the combined action of many factors (temperature, stress, water load, etc.) during construction or later operation. Here we explore the temperature and stress changes in the lining plate under different temperatures and water loads and determine the most unfavorable position (where the stress is more concentrated or the stress value is the largest) of the whole canal lining plate to provide guidance for the subsequent design, construction, and maintenance of canal linings. This paper takes a large irrigation district canal lining project in Henan Province, China as an example and uses ABAQUS finite element software to simulate the temperature and stress fields of the canal concrete lining plate under the combined actions of temperature, stress and water load. The results show that under both conditions of no water or water load, the temperature distribution is more uniform in the middle area of the canal bottom slab, and the temperature of the sunny side slope is higher than that of the shady side slope. The stress values of the lining plate and the bottom plate at the slope foot of the canal are large. Under the action of water load, the maximum stress of the right slope foot of the canal concrete lining plate reaches 2.38 MPa. Furthermore, the validity of the model is verified by comparing the error values, and parameters such as the elastic modulus and Poisson’s ratio were found to have a large influence on the sensitivity of the model. The results can be used as a reference for further research on canal concrete lining construction quality control.

Experimental study on pressure distribution of spur dike under the combined action of landslide surge and water flow

Combined with the physical model test of the force of landslide surge on the spur dike under the condition of water flow dynamics, this paper measures and analyzes the pressure distribution of the spur dike body, the wave pressure distribution along with the water depth, and the circumferential pressure distribution along with the near-surface layer, the middle layer, and a near-bottom layer of the upstream and downstream spur dikes of the river channel opposite the landslide entry point under the action of pure water flow and wave–current coupling, respectively. For the upstream spur dike, the maximum pressure is concentrated on the right side of the river slope of the spur dike body and the part of the backwater slope close to the spur dike head, that is, the position of the upstream slope; for the downstream spur dike, the pressure on the upstream slope and upstream slope of the spur dike head is the largest. Under the same test parameters, the pressure increase of the downstream spur dike is more significant than that of the upstream spur dike, and the downstream spur dike is easier to be damaged than the upstream spur dike.