Embankment Construction Research Articles

Deformation characteristics of red-mud embankment under monotonic and cyclic loads

The rapid growth in the production of the red mud has led to the shortage of land for stockpiling in recent years. Although red mud has been considered as the filling material for embankments, the deformation characteristics of a red-mud embankment under traffic loads has not yet been clarified. To promote its application in embankment construction, a series of centrifuge model tests of red-mud embankment under monotonic and cyclic loads were conducted. The deformation and failure processes of red-mud embankment under normal and overproof traffic loads were analyzed. The results show that the deformation characteristics of red-mud embankment varied significantly depending on the value of the external load. The deformation induced by monotonic load was greater than that induced by the cyclic load of the normal traffic load. The monotonic and cyclic loads of normal traffic load induced similar influential areas, and their deformation processes can be divided into rapid and slow growth parts. Shear failure occurred in the red-mud embankment under overproof traffic load. The same load increment induced more deformation of red-mud embankment after failure. Under reasonable dry density and water content, the deformation of red mud was acceptable, thus meeting the engineering requirements of embankment construction.

Strength degradation of foamed cement paste under sulfate attack

Foamed cement paste is increasingly being applied in the construction of road embankments, bridge abutments, slope treatments, and pipeline backfilling. Constructed foamed cement paste may suffer from sulfate attacks in certain environments, such as offshore regions and salty soil areas. However, the long-term performance of foamed cement paste under such circumstances remains unclear. In this study, laboratory tests are conducted to evaluate the strength deterioration of foamed cement paste after erosion by sulfate attack. Factors influencing the density of the foamed cement paste, concentration of the sulfate solution, and cation type (i.e., Na+ and Mg2+) are considered. The results indicate that the strength of the foamed cement paste decreases with increasing immersion time. The Na2SO4 solution has a more severe erosion effect than the MgSO4 solution when other conditions remain constant. Finally, X-ray diffraction is conducted to identify the phase of the crystalline material in the specimen. This study will be beneficial in the application of foamed cement paste in regions with salt-rich soils.

Methodology for determining the scope of reclamation works when forming recreational zone in the quarry residual space

The article is devoted to the development of methodological recommendations aimed at increasing the recreation territory during reclamation, taking into account the flooding of the quarry residual space. Calculations of the reclamation works volume during the forming of a recreation area on the quarry slope were made. The influence of the embankment section width of the soil in the flooded quarry space on the embankment geometric shape was established. Calculating method of the reclamation works volumes are proposed, taking into account the indicators of the slope inclination angle and the height of the embankment being formed. A scheme for the safe recreation area location within the quarry residual space has been developed, which allows determining the necessary parameters of the mining elements that affect on the volume of embankments construction. A method of determining the volume of works for the formation of a recreation area in the quarry is proposed, taking into account the embankment width and height, the resulting slope angle, the safe angle of mining rocks inclination at the dumping into flooded quarry. It has been established that the volume of reclamation depends on the embankment parameters when the quarry watered area is changed.

Physics-informed machine learning of multi-source monitoring data sparsely measured within a 2D vertical cross-section

Conventional machine learning (ML) methods suffer from several limitations, e.g., overreliance on large training datasets and poor performance in extrapolating beyond observations. Geotechnical monitoring data at specific sites are multi-sourced (e.g., settlement and horizontal displacement data). Moreover, each source of monitoring data may vary temporally and be sparsely measured, e.g., within a two-dimensional (2D) geological cross-section. Thus, effectively learning multi-source and limited monitoring data is difficult using existing ML methods. To address this challenge, this study proposes a physics-informed ML method combining geotechnical numerical models (e.g., the finite element model (FEM)) with sparse dictionary learning (SDL) methods. It uses a range of probable numerical model results corresponding to multiple, temporally varying responses in a 2D spatial range to construct a “dictionary” in SDL and employs multi-source and limited monitoring data to identify a few “atoms” from the constructed dictionary to improve model predictions. An engineering project for embankment construction is used to illustrate the proposed approach. Our results indicate that the proposed approach effectively integrates FEM results with multi-source and sparsely measured monitoring data and improves the predictions of multiple spatio-temporally varying geotechnical responses significantly, particularly those at subsequent time steps and unmonitored spatial locations within a 2D vertical cross-section.

Slope Stability and Reliability Analysis of Earth Embankment Constructed for the Doubling of Railway Track

Embankments of greater height pose threat to its stability and require geotechnical investigation and intervention. Conventionally, limit equilibrium approach is used to estimate the factor of safety of the slope to assess its stability. Over a period of time, with experience and engineering judgments, a factor of safety of 1.4 is deemed sufficient for Indian practice. In the approach, it is inherently assumed that different sources of uncertainty due to testing errors, model transformation, and inherent variability of the geo-material are taken care of with the use of single value of factor of safety. Still, a question remains, whether the suggested factor of safety is acceptable in a given environment of uncertainty or there is a need to further utilize the probabilistic approach. The present study demonstrates how combination of First Order Reliability Method (FORM), Finite Element Method (FEM) and Response Surface Method (RSM) can be useful in the probabilistic assessment of proposed construction of new earth embankment for the doubling of a railway track. It is further highlighted that conventional factor of safety approach when used in conjunction with probabilistic analysis brings rationality in decision making. Also, based on results of slope stability and reliability analysis, it is proposed to incorporate soil nailing to further improve the stability of the earth embankment.

Evaluation of the cooling performance of a crushed-rock interlayer embankment with longitudinal ventilation ducts in a pan-Arctic permafrost region

In pan-Arctic permafrost regions, longitudinal ventilation ducts are often installed in embankments to cool the underlying permafrost and thereby ensure road stability. However, the current design methods for embankments with longitudinal ventilation ducts (ED) normally simplify the conjugate heat transfer process between the duct wall and air in the duct. In this study, based on the chimney effect and the theory of fluid flow and heat transfer, we propose an improved numerical method for evaluating the cooling performance of the ED. Using this method, we conduct an assessment of the influences of duct configuration on the efficiency of ventilation duct cooling in winter. The results indicate that increasing the diameter of the duct and the height of the duct outlet can effectively improve the radial cooling range of the ventilation duct. However, the cooling performance of the ventilation duct becomes worse when the length of the duct is increased. To address the limited cooling performance of the ED, we design a crushed-rock interlayer embankment installed with longitudinal ventilation ducts (CED). It is found that the CED is more effective at maintaining the long-term thermal stability of the road in a typical pan-Arctic permafrost region when compared to the ED and the crushed-rock interlayer embankment. Furthermore, a cost analysis of the four different embankment designs reveals that the CED is a financially viable option for embankment construction in permafrost regions.

Pemodelan 2D Daerah Rawan Banjir Sungai Lepo – Lepo Kota Kendari

Research was carried out to see the potential for flooding through Computational Fluid Dynamic simulations, namely a set of methodologies that allow computers to provide numerical simulations of fluid flow. The entire system is transformed into virtual form, and can be visualized via computer. Components in fluid dynamic computing include selection of mathematical models, discretization, numerical analysis schemes, numerical solutions and representation of processes numerically and graphically. Flood mapping can provide information about which areas need special attention so that it can be used as a reference in making policies related to flood management and can be used to increase wider public awareness regarding floods. The HEC-RAS permanent flow module is able to take into account the influence of various flow obstacles, such as bridges, culverts, bends, or obstacles on riverbanks. The permanent flow module is designed for use in riverbank management environments and the determination of flood risk insurance regarding the determination of riverbanks and floodplains. The permanent flow module can also be used to estimate changes in water level due to channel improvements or embankment construction. HEC-RAS permanent flow special module features include double plan analysis, double profile calculation, double culvert or gate analysis, flow optimization, and stable channel design and analysis. From the simulation results and depth classification, information on the area of inundation and areas prone to flood inundation on the Lepo-Lepo River is 29.34 Ha.

Optimized reinforcement of granite residual soil using a cement and alkaline solution: A coupling effect

Granite residual soil (GRS) is a type of weathering soil that can decompose upon contact with water, potentially causing geological hazards. In this study, cement, an alkaline solution, and glass fiber were used to reinforce GRS. The effects of cement content and SiO2/Na2O ratio of the alkaline solution on the static and dynamic strengths of GRS were discussed. Microscopically, the reinforcement mechanism and coupling effect were examined using X-ray diffraction (XRD), micro-computed tomography (micro-CT), and scanning electron microscopy (SEM). The results indicated that the addition of 2% cement and an alkaline solution with an SiO2/Na2O ratio of 0.5 led to the densest matrix, lowest porosity, and highest static compressive strength, which was 4994 kPa with a dynamic impact resistance of 75.4 kN after adding glass fiber. The compressive strength and dynamic impact resistance were a result of the coupling effect of cement hydration, a pozzolanic reaction of clay minerals in the GRS, and the alkali activation of clay minerals. Excessive cement addition or an excessively high SiO2/Na2O ratio in the alkaline solution can have negative effects, such as the destruction of C-(A)-S-H gels by the alkaline solution and hindering the production of N-A-S-H gels. This can result in damage to the matrix of reinforced GRS, leading to a decrease in both static and dynamic strengths. This study suggests that further research is required to gain a more precise understanding of the effects of this mixture in terms of reducing our carbon footprint and optimizing its properties. The findings indicate that cement and alkaline solution are appropriate for GRS and that the reinforced GRS can be used for high-strength foundation and embankment construction. The study provides an analysis of strategies for mitigating and managing GRS slope failures, as well as enhancing roadbed performance.

Rob Flood Control on the North Coast of Java (Study on coastal areas of Pekalongan and Semarang)

Flooding on the coasts of Pekalongan and Semarang, North Coast of Java (Pantura), has become a severe problem for the Indonesian government. Factors causing the flood are rainfall, climate, land subsidence and rob, river conditions, tidal influence, poorer areas, land change, inappropriate flood control, damage to flood control buildings, excessive groundwater utilization, inappropriate flood management, river sedimentation, reduced water catchment areas, and runoff floods. Therefore, there is a need for an appropriate handling study to deal with these problems. This research aimed to determine the achievements of coastal flood control on the North Coast of Java. Data was collected through a literature review for secondary data, field studies for primary data, in-depth interviews with relevant stakeholders, and observation. The results showed that handling Rob flooding in coastal Pekalongan focuses on four locations: Bremi River, Meduri River, Mrican pump house, and Silempeng. Rob flood handling methods on the Pekalongan coast include the construction of concrete barriers with corrugated sheet pile (CCSP), compacted soil embankments with bamboo mattress reinforcement, and submersible pumping machines at the Mrican pump house. In comparison, rob flood management in coastal Semarang focuses on the Sringin and Tenggang rivers. The flood handling methods conducted are the provision of pumps, construction of Rob embankments and retention ponds, normalization, drainage improvements, and interconnection channels. However, handling coastal flooding needs a comprehensive and sustainable follow-up.

Field test study on thermal performance of a novel embankment using solar refrigeration technology

The embankment construction in permafrost regions affects the energy exchange process between the original ground and the surrounding environment, accelerates the degradation of the underlying permafrost layer, and endangers the stability of the embankment. To prevent permafrost degradation, a solar air conditioning system based on solar refrigeration technology was proposed. In this study, a field test of cooling embankment was carried out in permafrost regions, and the cooling performance of the new technology was analyzed. The solar air conditioning system shows good cooling performance, with a horizontal influence range of about 1.77–2.28 m and a vertical influence depth of more than 3 m. By active cooling, the temperature of the permafrost layer beneath the embankment decreased significantly, and the permafrost table rose by about 0.3 m. In addition, the influence mechanism of complex environmental factors on the cooling performance of the solar air conditioning system was revealed by correlation analysis and machine learning methods. Compared with existing technologies, solar refrigeration technology achieves active refrigeration during the whole season and presents a significant price advantage. The research results help promote the application of solar refrigeration technology in transportation geotechnics and provide a new approach for actively cooling embankments.

Cooling Performance of a Novel Ventilated Slope on Railbed in Permafrost Regions

ABSTRACTThe heat absorption of the railbed mainly originates from the embankment slope in permafrost regions. A novel ventilated slope (NVS) with a double‐layer convection channel is proposed and verified. By applying this method to the Qinghai–Tibet Railway (QTR), the annual average temperature at the 10 cm depth below the embankment slope surface under NVS was reduced by 4.95°C. The freezing index at the 10 cm depth of NVS was 1.78 times higher than that of the slope without any cooling approaches. The numerical simulation results showed that heat was accumulated for the conventional embankment, while heat was released from the railbed after the application of NVS. With the cooling effect of NVS, the 0°C isotherm would rise above the original natural ground surface in the 2nd year after the embankment construction. A low‐temperature region of −2°C would be observed in the underlying permafrost by the 10th year. The underlying permafrost would remain frozen in the 50th year. This study provides a novel method for protecting the underlying permafrost in permafrost regions.

Correlation of Geotechnical and Mineralogical Properties of Lithomargic Clays in Uttara Kannada Region of South India

The present study explores the intricate relationship between the geotechnical and mineralogical properties of lithomargic clays in the Uttara Kannada region of south India. Lithomargic clays, characterized by their unique composition of clay minerals and calcareous content, play a crucial role in the geotechnical behavior of soils. The study aims to provide a comprehensive understanding of the interplay between the mineralogical composition and engineering characteristics of lithomargic clays, shedding light on their suitability for various construction and infrastructure projects. The research methodology involves a systematic analysis of lithomargic clay samples collected from different locations in the Uttara Kannada region. Geotechnical investigations, including particle size distribution, Atterberg limits, unconfined compressive strength (UCS), California bearing ratio (CBR) and triaxial tests, are conducted to assess the engineering properties of the clays. Concurrently, mineralogical analyses, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM), are employed to identify and quantify the clay mineral constituents within the samples. The findings of this study reveal correlations between specific mineralogical features and geotechnical behaviors of lithomargic clays. Understanding these relationships is crucial for predicting the response of these clays to different engineering applications, including slope stability, foundation design and embankment construction. The research contributes valuable insights to the scientific and engineering communities, aiding in the informed utilization of lithomargic clays in geotechnical projects in the Uttara Kannada region and beyond. The outcomes of this investigation, such as the correlation of geotechnical properties with the variation in minerals in various sample locations, enhance our understanding of the complex nature of lithomargic clays, providing a foundation for more sustainable and effective engineering practices in the geologically diverse landscapes of south India.

From Chingford to Carsington: impact of soil mechanics on dam construction, 1937–1987

In 1937 the investigation of the failure during construction of Chingford number 2 embankment dam brought the concepts of modern soil mechanics to bear on the construction of British embankment dams. Effective stress theory highlighted the crucial significance of pore-water pressure in understanding embankment stability and it became standard practice to monitor pore pressures during embankment construction using twin-tube hydraulic piezometers. By the 1980s, embankment stability might have seemed assured, with embankment design utilising limit equilibrium stability analyses that incorporated strength parameters of fill and foundation materials determined by laboratory testing. However, in 1984 the upstream slope of Carsington dam suffered a major slip in the final stage of construction. Recently developed advanced finite-element analyses were able to demonstrate that progressive failure was a major factor in the slope instability, but the failure was also a reminder of the continuing need for experience-based judgement in design.

The Impacts of River Channel Blockages Caused by Sliding Embankment Collapses during Earthquakes

New Japanese regulations governing earth embankment construction were introduced after a debris flow in Atami City, Shizuoka Prefecture, caused significant damage. Slope failures block river channels during earthquakes, triggering flooding, inundation, and debris flows. Appropriate risk assessments are crucial for residential areas potentially impacted by earthen embankment landslides during seismic events. This study evaluates the methods used to assess the potential damage caused by such landslides and previous research on the harm caused by embankment failures during earthquakes. We derived predictive equations based on statistical analyses of historical dam landslides that triggered river channel blockages when residential earth embankments failed in the Nigawa Yurino area. The equations describe the morphologies of landslide dams in river channels. The results indicated that the predictive equations were reasonably accurate. We built and validated a two-dimensional model of landslide dam overtopping and breaching using experimental data on a gently sloping dam. We derived the outflow volumes associated with residential earth embankment failures when full reservoirs breached in the Nigawa Yurino area. Our findings suggest that the peak outflow volumes after such embankments breach are generally lower than those associated with dam landslides or deep-seated dam failures, but higher than those of glacial lake outburst floods.

Enhancing California Bearing Ratio through Optimized Compaction Efforts: A Study on Alluvial Soils in North India

The quantity of soil required for embankment construction is enormous. Often the soil is brought to the site in dumpers in multiple rounds. This to and from movement of the wagons leads to the deterioration of the existing flexible pavement. In the absence of good earth nearby, using existing soils to act as a subgrade material upon meeting the desired strength and stability characteristics is the need of the hour. The California Bearing Ratio (CBR) is an indicator of soil's strength, which further depends on the degree of compaction of soil. In this study, an effort has been made to find the required compaction efforts to achieve maximum CBR value finding its applicability for both conventional flexible and perpetual pavements. Three different types of alluvial soils in North India were tested for CBR with varying compaction efforts using the modified Proctor test. The effect of mixing different soils was also considered to find the effectiveness of mechanically mixing soils on the required compaction efforts. It was observed that there is a constant upsurge in the CBR of soils upon an increase in the percentage compactive effort up to a certain limit. In the case of clayey soils, the rate of increase is less as compared to the well-graded sands. This study also highlights the effect of mechanical mixing of such soils with sandy soils in desired proportions giving rise to amplified values of CBR ratio of the soil blend. The regression analysis was also conducted to examine a correlation between the compactive effort and CBR values and it was best represented by exponential function for different types of soils.

Www.ijeit.misuratau.edu.ly ISSN 2410-4256 Paper ID: EN017 Soil Improvement Technique for Pilot Section as New Railway Project in Libya

The construction of embankments on soft saturated soils can be a challenge due to the low shear strength and high compressibility of these soils. The application of reinforced and pile-supported embankments to sustain the imposed dead and traffic loads for train speeds of up to 250 km/h is recently growing in Libya. The aim of this study examine the performance of Geogrid-reinforced embankments with Vibro- stone columns as a ground improvement method adopted in "Pilot Section Al Khoms" subject to cyclic loadings that are applied over a specific area of the embankment to improve strength and provide a safe and economical design for the whole coastal railway. The main result from the load plate test indicates that the stringent performance requirements of the new railway project were met. Furthermore, it was observed that with an increasing number of reinforcement Geogrid layers, enormous cycles of loading could be applied without experiencing excessive deformation and an important reduction in the stress and settlement on the subgrade. The results from field experience, show the project was completed on time and the ground improvement method adopted was employed successfully to reduce the costs of construction maintenance of embankments in the high-speed railway project.

Effect of Embankment Construction Pace on Slope Stability Wih Varied Heights on Organic Soft Soil in the Sicincin-Padang Toll Road Sta 10+250-10+400

Effect of Embankment Construction Pace on Slope Stability Wih Varied Heights on Organic Soft Soil in the Sicincin-Padang Toll Road Sta 10+250-10+400

Variation of Satellite-Based Suspended Sediment Concentration in the Ganges–Brahmaputra Estuary from 1990 to 2020

The Ganges–Brahmaputra estuary, located in the northern Bay of Bengal, is situated within the largest delta in the world. This river basin features a complex river system, a dense population, and significant variation in watershed vegetation cover. Human activities have significantly impacted the concentration of total suspended matter (TSM) in the estuary and the ecological environment of the adjacent bay. In this study, we utilised the Landsat series of satellite remote sensing data from 1990 to 2020 for TSM retrieval. We applied an atmospheric correction algorithm based on the general purpose exact Rayleigh scattering look-up-table (LUT) and the shortwave-infrared (SWIR) bands extrapolation to Landsat L1 products to obtain high-precision remote sensing reflectance. In conjunction with the normalised difference vegetation index (NDVI), precipitation, and discharge data, we analysed the variation and influencing mechanisms of TSM in the Ganges–Brahmaputra estuary and its surrounding areas. We revealed notable seasonal variation in TSM in the estuary, with higher concentrations during the wet season (May–October) compared to the dry season (the rest of the year). Over the period from 1990 to 2020, the NDVI in the watershed exhibited a significant upward trend. The outer estuarine regions of the Hooghly River and Meghna River displayed significant decreases in TSM, whereas the Baleswar River, which flows through mangrove areas, showed no significant trend in TSM. The declining trend in TSM was mainly attributed to land-use changes and anthropogenic activities, including the construction of embankments, dams, and mangrove conservation efforts, rather than to runoff and precipitation. Surface sediment concentration and chlorophyll in the northern Bay of Bengal exhibited slight increases, which means the limited influence of terrestrial inputs on long-term change in surface sediment concentration and chlorophyll in the northern Bay of Bengal. This study emphasises the impact of human activities on the river–estuary–coast continuum and sheds light on future sustainable management.

Impacts on Embankments, Rigid and Flexible Barriers Against Rockslides: Model Experiments vs. DEM Simulations

AbstractAs a result of climate change, rockfalls and rock avalanches as well as landslides lead to an increasing hazard for settlement areas and infrastructures. The hazards of such mass movements mean that numerous protective structures must be planned and built. In addition to building such constructions, the refurbishment of existing protective structures is also playing an increasingly important role. Some of these protective structures are rigid structures consisting of concrete and/or steel elements. Due to the difficult accessibility, flexible net constructions are often considered. Embankment constructions are normally erected to protect against large mass movements. The choice of the right type of construction is based not only on geotechnical and geographical conditions, but also on the occurring energies and the impact of rockslides on the protective structure. In this study, small-scale laboratory experiments with different protective structures are presented. Rigid and flexible structures as well as reinforced embankments are investigated. Based on the results of the experiments, the impacts and deformations are recalculated numerically using the discrete element method (DEM). From the small-scale laboratory experiments and numerical simulations, the differences regarding the construction type of the protective structure can be investigated. An essential main point concerns the relationship between the flexibility of the barrier and the total impact load. The presented work is limited to the investigation of strongly fragmented gravitational mass movements such as rock avalanches.

Environmental implications of styrofoam waste and its utilization as lightweight fill material for embankment construction

This study investigates the adverse effects of styrofoam waste on the environment due to its non-biodegradable nature and persistence in natural ecosystems, encompassing issues such as visual pollution, habitat disruption, and potential health risks to flora and fauna. The research also delves into the feasibility of repurposing styrofoam waste as a lightweight fill material in embankment construction, aiming to improve the performance of such structures, with the primary objective of augmenting the structural performance of such constructions. The paper conducts an extensive assessment of the technical properties and engineering characteristics of a soil-styrofoam mixture. Key parameters under scrutiny encompass density, shear strength, and bearing capacity behaviors. Various proportions of styrofoam, specifically 0.0%, 0.2%, 0.4%, 0.6%, and 0.8% by weight, were systematically incorporated into the soil mixture. Based on this study, the use of styrofoam can reduce the maximum dry density of the soil mixture, but still has the desired bearing capacity. These results indicate that the reuse of Styrofoam waste as an additional material in embankment construction has great potential to improve the performance and sustainability of embankment projects.