Embankment Side Research Articles

Near-Surface Soil Moisture Characterization in Mississippi’s Highway Slopes Using Machine Learning Methods and UAV-Captured Infrared and Optical Images

Near-surface soil moisture content variation is a major factor in the frequent shallow slope failures observed on Mississippi’s highway slopes built on expansive clay. Soil moisture content variation is monitored generally through borehole sensors in highway embankments and slopes. This point monitoring method lacks spatial resolution, and the sensors are susceptible to premature failure due to wear and tear. In contrast, Unmanned/Uncrewed Aerial Vehicles (UAVs) have higher spatial and temporal resolutions that enable more efficient monitoring of site conditions, including soil moisture variation. The current study focused on developing two methods to predict soil moisture content (θ) using UAV-captured optical and thermal combined with machine learning and statistical modeling. The first method used Red, Green, and Blue (RGB) color values from UAV-captured optical images to predict θ. Support Vector Machine for Regression (SVR), Extreme Gradient Boosting (XGB), and Multiple Linear Regression (MLR) models were trained and evaluated for predicting θ from RGB values. The XGB model and MLR model outperformed the SVR model in predicting soil moisture content from RGB values. The R2 values for the XGB and MLR models were >0.9 for predicting soil moisture when compared to SVR (R2 = 0.25). The Root Mean Square Error (RMSE) for XGB, SVR, and MLR were 0.009, 0.025, and 0.01, respectively, for the test dataset, affirming that XGB was the best-performing model among the three models evaluated, followed by MLR and SVR. The better-performing XGB and MLR models were further validated by predicting soil moisture using unseen input data, and they provided good prediction results. The second method used Diurnal Land Surface Temperature variation (ΔLST) from UAV-captured Thermal Infrared (TIR) images to predict θ. TIR images of vegetation-covered areas and bare ground areas of the highway embankment side slopes were processed to extract ΔLST amplitudes. The underlying relationship between soil surface thermal inertia and moisture content variation was utilized to develop a predictive model. The resulting single-parameter power curve fit model accurately predicted soil moisture from ΔLST, especially in vegetation-covered areas. The power curve fit model was further validated on previously unseen TIR, and it predicted θ with an accuracy of RMSE = 0.0273, indicating good prediction performance. The study was conducted on a field scale and not in a controlled environment, which aids in the generalizability of the developed predictive models.

Verification of Structural Strength of Spur Roads Constructed Using a Locally Developed Method for Mountainous Areas: A Case Study in Kochi University Forest, Japan

Owing to steep terrain and complicated geology, constructing spur roads with low cost and sufficient strength is crucial for sustainable forest management in Japan. The Shimanto method was developed for making narrow spur roads robust against collapse around the 2000s in the Shimanto geology belt area, where the strata were slanted because of an accretion wedge. Kochi University Forest adopted this method and constructed some routes of spur roads in the 2010s. In the present study, we assessed the performance of this method in terms of the roadbed strength and bearing capacity. Two routes were selected, namely Sites 1 and 2, constructed in 2013–2016 and 2019–2021, and tested in 2017 and 2021, respectively. The roadbed strength was measured up to a depth of 100 cm using a handy dynamic cone penetrometer with a rammer of 5 kg. The results showed that the roadbed strength of the embankment side was weaker than that of the cut slope side, although the method was supposed to compact the roadbeds equally over the road width. However, most of the roadbeds had sufficient strength; the younger ones tended to have lower strength than the older ones, and the same tendency was observed for the bearing capacity. It was suggested that the soil under the road width should be excavated more widely toward the cut slope side before compaction.

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.

An impervious sand used as separation layer in collapsible loess embankment: A case study

In this study, a novel impervious sand is modified from the desert sand. It has a good waterproofing and thermal-isolating capacity. Hence. it was used as the separation layer in the collapsible losses embankment to prolong the service life. It has the advantages of lightweight, good waterproofing effect, and cycled usage. The application of impervious sand in collapsible losses embankment could constrain water immigration effectively. Hence, local collapsible losses could be used in highway construction, which means the construction cost could be saved to a large extent. In this study, an artificial fill and impervious sand of different thicknesses were both used in collapsible losses embankment. In-suit monitoring on soil temperature, water content, settlement, and strains of different directions were conducted for more than one year. Hence, the waterproofing effect between the artificial fill and impervious sand could be compared. Furthermore, the collapsible losses embankment side slope stability was calculated through a finite element model. The long-term performance of embankment stability, which took the filling loess’s water content into consideration, was also calculated and compared between the separation layer made of artificial fill or impervious sand.

The role of Soviet modernism objects in the formation of Rostov-on-Don silhouette along the Don River embankment

The active use of the landscape features in urban areas for the architectural environment formation has become a topical method of urban planning in the USSR. Developed in the late 1960s the new master plans for the large cities in the country primarily emphasized the existing natural features. Rostov-on-Don was no exception. Here, the main principle of urban planning in the early 1970s began to focus on the urban development disclosure in the direction of the Don River, which continued the tradition of the general plan of the 1930s and the post-war reconstruction concept. It was planned to demolish the dilapidated and warehouse buildings that had built up the slope descending from the city to the river, as well as to preserve the valuable historical sites and create the new structures in the form of modernism. The article analyzes the principles of the formation of silhouette buildings in Rostov-on-Don from the central embankment side. In the course of field studies and photographs, a panorama of the central embankment of the 1970-1980s city was compiled, the planning of the panorama, spatial landmarks and axes were revealed. The objects of modernism participating in the silhouette creation are analyzed as well as their role is determined depending on their location relative to the river (on the embankment, on the slope, in the central building). Unrealized structures of the 1970s, revealing the general principles of building spatial landmarks, have been studied.

Mitigating high-speed train vibrations with EPS blocks for various soil conditions

Ground-borne vibrations due to high-speed trains passage strongly depend, apart from the speed of the train, on the geometry of the railways as well as the properties of the underlying soil layer(s). The main aim of this study is to investigate the effectiveness of expanded polystyrene (EPS) blocks in mitigating soil vibrations induced on railway embankments for different subsoil and railway embankment material conditions. The EPS blocks are placed in suitable locations, either as embankment's side fill material, or trench filling material, or combination of the above. An efficient three-dimensional numerical model has been developed -in conjunction with a user-developed subroutine for applying the moving loads-to accurately calculate the dynamic response of the coupled embankment-soil model. Four typical soil types - categorized as rock, dense sand with gravels, stiff and soft clay - are investigated. In addition, the mechanical properties of the embankment material have been altered to assess to what extend they can affect the HST vibrations.

Proposal Studies of Using Eco-Protection for the Highway Embankment Side Slope Erosion in Sudan by Applying Native Vegetation

Proposal Studies of Using Eco-Protection for the Highway Embankment Side Slope Erosion in Sudan by Applying Native Vegetation

Study the Native Vegetation around the <i>Al Hosh</i> Highway Slope in Sudan (Gezira State) as Bioengineering Method of Slope Erosion Protection

Soil erosion occurs due to rainfall intensity and soil movement had become one of the disasters faced by Al Hosh highway today. And the carelessness (Where there is no any type of protection) it has also caused occur the soil erosion due unprotected embankment side slope of the Al Hosh highway, which affect widely of the loss of human lives according to traffic accidents, the destruction of cars and large vehicles. Although the area is usually categorized as eroded area because of high rainfall intensity during the autumn season time, the Middle East states of the Sudan as Gezira state is known by the heavy rainfall. As stabilization of slopes using mechanical structures is costly to establish and maintain, biotechnical slope protection is an alternative which is more aesthetically pleasing and cost effective. Hence, in this research, an overall study on the positive impacts of the presence of native vegetation for the slope stability were studied in the Al Hosh embankment side slope. Trying to use native vegetation as the local grasses to restore the Al Hosh highway slope as a new bio-engineering method in Sudan. This paper explores the review the native vegetation and its ability to use it in protecting Al Hosh slope erosion with different slope angles by identification, categorization and studying of the salient features of them according to the soil classification for relevant slope by using both Unified Soil Classification System and US Department of Agriculture. This research recommends suitable native vegetation against soil erosion and subsequent slope failures in cut slopes.

The albedo of crushed-rock layers and its implication to cool roadbeds in permafrost regions

The construction of roadway embankments may destabilize the thermal stability of roadbeds in permafrost regions. One mitigating strategy is to face the embankment side slopes with a crushed-rock layer, which promotes convective cooling and cools the underlying permafrost. While research on the convective cooling of the crushed-rock layer is fairly plentiful, the solar absorption of this layer remains unknown in the current stage. Measuring the albedo of a crushed-rock layer is crucial to estimate the thermal performance of the roadway embankment. This study proposes the theory and procedure for measuring the albedo of crushed-rock layers. The albedo of crushed-rock layers with different sizes of aggregate is measured in sunny and cloudy weather. It was found that the albedo of crushed-rock layers decreases with the increase of the aggregate size. The reason for this correlation is that at a rough surface, some photons leaving the surface return to it, increasing its absorption. Incorporating light-colored aggregates on a highway surface or side slope layer may raise the highway albedo and cool the underlying permafrost.

Experimental study on the solar reflectance of crushed rock layer with different sizes

A crushed rock layer is often reveted on a cold-region embankment side slope to keep the underlying permafrost layer cool. However, its cooling effect is strongly affected by the solar absorption of this layer. This study proposes a procedure for measuring the albedo of a heterogeneous surface like a crushed rock layer. The albedo of crushed rock layers with different aggregate sizes is measured. It is found that the albedo of the crushed rock layer decreases with the aggregate size and that the albedo of the crushed rock layer is 0.1–0.2 lower than the albedo of the fresh flat rock. This is because the multiple reflections in the inter-aggregate cavity increase the solar absorption of the layer. Painting the crushed rock layer with high-reflective pigments can increase the albedo of the layer about 0.10–0.20, with the greater increase for the layer with the larger aggregate size.

Painting the roadway embankment with non-white high reflective pigments to raise the albedo

Roadway in permafrost regions usually needs embankments to disperse the traffic stresses to the underlying layers. As a bent surface, the diffuse reflections leaving the surface may return to it, increasing the solar absorption of the embankment. The purpose of this study is to illustrate the possibility of raising the embankment section’s albedo as a strategy to cool the roadbed. This study searched for a group of non-white pigments with high reflectivity for the near-infrared light but low reflectivity for the visual and ultraviolet light. These pigments were painted on the surface of the embankment model, whose albedo was estimated by a proposed procedure for measuring the albedo of a bent surface. It is found that increasing the embankment surface albedo of 0.10 could raise the embankment albedo of 0.09. The residual 0.01 is because multiple reflections between the embankment side slope and its adjacent ground increase the side-slope solar absorption. Further experiments are expected to measure the albedo of bare soils and crushed rock layers with high reflective non-white pigments painted.

Shading boards with smaller lower-surface thermal emissivity perform better cooling effect

Roadway embankments over permafrost stratum are susceptible to thawing damage. Installing shading boards on the embankment side slope reflects solar irradiance back to the sky and thus has been deemed as a roadbed cooling technique. Research on the cooling effect of shading boards has centered on the temperature evolution of the roadbed under the board and on the optimum design of the board. Few researches, however, have been dedicated to understand the heat balance between the board and the embankment and to adapt the board's thermal properties to maximize the cooling effect. This study models the heat flux balance between the board and the embankment side slope and validates the model with measured data logged from an in situ shading board experiment. The validation of the model reveals that shading boards with smaller lower-surface thermal emissivity perform stronger cooling effect. Further outdoor experiments are expected to paint the shading board upper surface with differential albedo to understand the influence of board albedo on the cooling effect.

Effect of Slope and Loading Direction on Laterally Loaded Piles in Cohesionless Soil

An extensive program of laboratory model tests was undertaken to study the effect of slope and loading direction on laterally loaded piles in cohesionless soil. The paper includes studies of the effect of distance from the crest of the slope (both slope side and embankment side), soil properties, and loading direction (both forward in the direction of the slope and reverse loading). The pile lateral capacity in sloping ground was compared with that in horizontal ground. From the experimental investigation, it is observed that when piles installed in sloping ground undergo forward loading, lateral capacities of the piles are almost reached at 8% of the pile diameter in loose-to-medium dense soil and 16% of the pile diameter in dense soil. If the pile is placed >15 times the pile diameter away from the slope crest within the embankment, the influence of slope in the lateral-load capacity is almost negligible under both forward and reverse lateral load.

Stability analyses for levees on deep-mixed shear walls

The deep-mixing method can increase the strength of soft ground, and thereby improve the stability of earthen levees. Additional benefits are that deep-mixing support can accelerate construction and protect adjacent facilities from deformations that would otherwise be induced by the new embankment loads. Continuous shear walls located under the embankment side slopes and oriented perpendicular to the embankment centreline are more efficient for stability than isolated columns because shear walls are not subject to the same type of bending failure that isolated columns can experience. Even when continuous shear walls are used, stability analyses must consider multiple modes of failure, such as composite shearing, rotation of the deep-mixed zone, shearing on vertical planes along column overlaps, extrusion between shear walls, crushing of the deep-mixed ground at the toe of the deep-mixed zone and global instability. This paper presents simplified analysis methods for stability of earthen levees supported on deep-mixed shear walls.

Numerical analysis of wind speed variation under awning boards covering embankment side slopes

To protect the permafrost under the embankment from thawing and to ensure the safety and smoothness of the road, the use of shading boards (awnings) was one of the main measures applied along the side slopes of the Qinghai–Tibet Highway, the Qinghai–Tibet Railway and the Qingkang–Highway embankments. Aside from the shading effect acting against solar irradiation such constructions may also help to channel the natural wind flow and thus contribute to the cooling of the embankment and the underlying ground by enhancing the natural wind flow close to the surface. In this study we present results from numerical finite element simulations of the air flow under two different awning designs, with the aim to find an optimal geometry and awning height to be applied in future engineering work. We compare the air flow profiles across and along the awning headroom and investigate the influence of embankment slope inclination on the flow under the awning.

An experimental study on the cooling mechanism of a shading board in permafrost engineering

Shading boards (SB) were tested on an embankment slope as one of the measures for actively cooling permafrost in roadbed engineering along the Qinghai-Tibet Highway on the Tibet Plateau, China. A series of tests, evaluating the cooling mechanism of SBs, also were conducted in the laboratory that showed that the SB cooled the permafrost by significantly reducing the input of solar radiation onto the side slope surfaces. In these laboratory tests, the radiation intensity was lowered by 85.5%. In addition, the enhanced air convection between the SB and the slope surface removed the heat produced by the secondary radiation from the back side of the board, as well as heat released from the soil. Laboratory tests indicate that the temperature on the slope surface lowered in more degree with the SB can be explained by the “stack effect” triggered between the SB and the slope surface. The accelerated air flow under the SB brings the temperature of the slope surface to ambient air temperature. There was an optimal height of 15 cm for the SB, where the air flow reached its maximum amount and velocity, which means that, in practice, the installed height of the SB should be taken into account. Also, the free flow of the air under the SB should be assured by leaving the space between the SB and the protected surface unblocked. Practical applications of the SB along the Qinghai-Tibet Highway from November 2003 to November 2004 showed that the SB could reduce the annual average surface temperature of the entire embankment side slope by about 3.2 °C compared with the unshaded embankment slope. The maximum reduction was 4 °C. The annual average slope surface temperature under the SB was about 1.5 °C lower than the nearby natural ground surface.

5701763 Cryogenic hybrid system for producing low purity oxygen and high purity nitrogen

The construction of roadway embankments may destabilize the thermal stability of roadbeds in permafrost regions. One mitigating strategy is to face the embankment side slopes with a crushed-rock layer, which promotes convective cooling and cools the underlying permafrost. While research on the convective cooling of the crushed-rock layer is fairly plentiful, the solar absorption of this layer remains unknown in the current stage. Measuring the albedo of a crushed-rock layer is crucial to estimate the thermal performance of the roadway embankment. This study proposes the theory and procedure for measuring the albedo of crushed-rock layers. The albedo of crushed-rock layers with different sizes of aggregate is measured in sunny and cloudy weather. It was found that the albedo of crushed-rock layers decreases with the increase of the aggregate size. The reason for this correlation is that at a rough surface, some photons leaving the surface return to it, increasing its absorption. Incorporating light-colored aggregates on a highway surface or side slope layer may raise the highway albedo and cool the underlying permafrost.

Spatially Varied Flow over an Embankment Side Weir

Overtopping of embankments during floods leads to a spatially varied flow (SVF). In order to estimate the water surface profiles and the amount of water spilling over the embankment for a given steady-state flow condition, a mathematical model for SVF over a broad-crested weir is formulated. The mathematical model is tested for accuracy using laboratory experiments. The computed water surface profiles and the discharge estimates are within 3 and 10%, respectively, of the experimentally observed values.

Discussion on ‘A55 Pwll Melyn slip and remedial works: a case history’ by A. Siva Subramaniam and R. W. Carr

G. H. C hild and D. R. N orbury write: From our investigation of the slip when active we would like to make the following comments. Although we did not find shear zones in borehole samples, overnight movement of drill casing in two holes and positive response from a slip indicator in another enabled us to identify the surface of sliding under the embankment side slope which the authors confirmed. We disagree with the authors on the location of the back of the slip, considering the crack in the road to be a secondary feature. In our investigation we considered the primary slip surface to be as shown on Fig. 1 Figures 2 and 3 show the top and toe of the slip on 25 October 1976. The casing of the borehole commenced on the verge and referred to in the paper can be seen in Fig. 2 At this stage major movement had occurred and was all downslope of the road. Figures 3 shows the surface ruckling that had already occurred in the field below. Because of the large crack in the embankment side slope we question the authors’ conclusion regarding the significance of pore water pressures in the fluvioglacial deposits uphill from this crack. Pore water pressures to their line A or above seem most improbable since this would imply flooding of the old A55 road. We agree that the embankment fill was relatively permeable; gradings indicated that it was probably more permeable than the fluvioglacial sand. Therefore, a feature

Basic Blues, and: On the Ledge, and: A Bower of Roses

Louis Simpson 5 BASIC BLUES / Louis Simpson Three comrades . . . there are always three. The one with his cap cocked rakishly tosses a coin, and they're off. But it's hopeless. Ever since Pearl Harbor all the women have been hidden away as though by magic. The length of Main Street, and Market, and Figueroa . . . They keep walking past houses with lawns and trees. In an area where there are benches they sit and gaze at the grass being watered and the names of flowers and trees: Pyracantha, Golden Rain Tree, Ceniza. A vagrant breeze rustles the leaves and they become aware that time is passing. They take the bus back to town. By now it is the middle of the afternoon, the light on concrete is glittering, the heat rising in waves. They hold another sidewalk conference and decide to settle for the movie. It's time to return to the depot and the ride back . . . looking at fields, small trees, houses like wooden boxes, a church with "Praise the Lord." 6 THEMISSOURIREVIEW They've been travelling for hours. When the bus brakes for a stop the sleepers stir, and someone asks, "What time is it?" The streets are dark and desolate. O, all the wars in Germany and Russia will not make them grieve like a Shell station, and Lone Star Bar, and the Hotel Davy Crockett. Louis Simpson 7 ON THE LEDGE / Louis Simpson I can see the coast coming near . . . one of our planes, a Thunderbolt, plunging down and up again. Seconds later we heard the rattle of machine guns. That night we lay among hedgerows. The night was black. There was thrashing in a hedgerow, a burst of firing . . . in the morning, a dead cow. A plane droned overhead . . . one of theirs, diesel, with a rhythmic sound. Then the bombs came whistling down. We were strung out on an embankment side by side in a straight line, like infantry in World War One waiting for the whistle to blow. The Germans knew we were there and were firing everything they had, bullets passing right above. I knew that in a moment the order would come. There is a page in Dostoievsky about a man being given the choice to die, or to stand on a ledge through all eternity . . . alive and breathing the air, looking at the trees, and sky . . . the wings of a butterfly as it drifts from stem to stem. 8 THEMISSOURIREVIEW But men who have stepped off the ledge know all that there is to know: who survived the Bloody Angle, Verdun, the first day on the Somme. As it turned out, we didn't have to. Instead, they used Typhoons. They flew over our heads, firing rockets on the German positions. So it was easy. We just strolled over the embankment, and down the other side, and across an open field. Yet, like the man on the ledge, I still haven't moved . . . watching an ant climb a blade of grass and climb back down. Louis Simpson 9 A BOWER OF ROSES / Louis Simpson The mixture of smells— of Algerian tobacco, wine barrels, and urine— I'll never forget it, he thought, if I live to be a hundred. And the whores in every street, and like flies in the bars . . . Some of them looked familiar: there was a Simone Simone, a Veronica. And some were original, like the two who stood on a corner, a brunette with hair like ink and a platinum blonde, holding a Great Dane on a leash. "A monster," said Margot. "Those two give me the shivers." The other girls were of the same opinion. One said, "And, after all, think what a dog like that must cost to feed." This was conclusive. They stared out at the street— there was nothing more to be said. When they gave him a pass at the hospital he would make for the bar in Rue Sainte Apolline Margot frequented. Sitting in a corner as though she had been waiting . . . Like the sweetheart on a postcard gazing from a bower of roses . . . "Je t'attends toujours." 10 THEMISSOURIREVIEW For ten thousand francs she would let him stay the night...