Safety Of Embankments Research Articles

Village road restoration in electrical steam power plant area in Banten, Indonesia through embankment reinforcement using geoframe technology

This paper presents a case study of the restoration of village road located between Zone 2A and Zone 2B after the excavation for box culvert underneath it. Geotechnical investigations showed that the area will be constructed upon volcanic rock material. The height of the Geoframe is approximately 19.7 meters. This system is a combination of polyester strip for reinforcing element and connected with clamp to the facing made of galvanized steel as a permanent formwork and non-woven geotextile material for filter element. The inclination of Geoframe structure can reach almost vertical with over 85⁰ inclined facing. The result of this work, Geoframe’s facing can be grown with vegetation (grass) to accentuate a natural and green structure. From design perspective, the embankment safety factor was above the criteria stated in Indonesian National Standard for Geotechnical Design Requirements which is above 1.50 and design with pseudo-static earthquake load which is above 1.10. The system has proven to be easy to implement in the field, fast and can be carried out with good quality control.

Embankment surface crack pixel-wise identification in UAV images based on a lightweight U-Network with transfer learning

Embankments in challenging environments experience cyclic external influences and loads that render their surfaces susceptible to a range of defects, with cracks particularly menacing. Therefore, accurate and efficient crack identification holds paramount significance for embankment safety. This paper addresses the challenges of low crack recognition rates on complex embankment surfaces and the high training costs associated with deep learning-based crack detection methods. We introduce a novel residual structure as the foundational innovation, followed by developing a streamlined U-shaped network (denoted as U²-Net_Aggregation) that amalgamates multi-scale insights by integrating skip connections. The newly devised U²-Net_Aggregation network demonstrates significant improvements in accuracy, intersection over union (IOU), and F1-score metrics through ablation tests on three distinct crack datasets. Comparisons with commonly employed crack detection methods (FCN, SegNet, U-Net, DeepCrack, and U²-Net) were conducted at the pixel level using an embankment crack dataset. Results unequivocally showcase enhancements in both accuracy and processing speed. To overcome the challenge of a high application threshold resulting from a scarcity of training data specific to embankment cracks, we compile an extensive dataset featuring diverse building crack scenarios, serving as a foundation for transfer learning. Following transfer learning, U2-Net_Aggregation attains recall, IOU, and F1-score values of 87.31%, 81.76%, and 90.06%, respectively. The proposed methodology enables swift and accurate crack detection by directly utilizing Unmanned Aerial Vehicle (UAV) images, offering a novel avenue for embankment crack detection in real-world field scenarios.

Evaluating the accuracy and effectiveness of machine learning methods for rapidly determining the safety factor of road embankments

PurposeSlope stability analysis is essential for ensuring the safe design of road embankments. While various conventional methods, such as the finite element approach, are used to determine the safety factor of road embankments, there is ongoing interest in exploring the potential of machine learning techniques for this purpose.Design/methodology/approachWithin the study context, the outcomes of the ensemble machine learning models will be compared and benchmarked against the conventional techniques used to predict this parameter.FindingsGenerally, the study results have shown that the proposed machine learning models provide rapid and accurate estimates of the safety factor of road embankments and are, therefore, promising alternatives to traditional methods.Originality/valueAlthough machine learning algorithms hold promise for rapidly and accurately estimating the safety factor of road embankments, few studies have systematically compared their performance with traditional methods. To address this gap, this study introduces a novel approach using advanced ensemble machine learning techniques for efficient and precise estimation of the road embankment safety factor. Besides, the study comprehensively assesses the performance of these ensemble techniques, in contrast with established methods such as the finite element approach and empirical models, demonstrating their potential as robust and reliable alternatives in the realm of slope stability assessment.

A real-time prediction interval correction method with an unscented Kalman filter for settlement monitoring of a power station dam

A prediction interval (PI) method is developed to quantify the model uncertainty of embankment settlement prediction. Traditional PIs are constructed based on specific past period information and remain unchanged; hence, they neglect discrepancies between previous calculations and new monitoring data. In this paper, a real-time prediction interval correction method is proposed. Time-varying PIs are built by continuously incorporating new measurements into model uncertainty calculations. The method consists of trend identification, PI construction, and real-time correction. Primarily, trend identification is carried out by wavelet analysis to eliminate early unstable noise and determine the settlement trend. Then, the Delta method is applied to construct PIs based on the characterized trend, and a comprehensive evaluation index is introduced. The model output and the upper and lower bounds of the PIs are updated by the unscented Kalman filter (UKF). The effect of the UKF is compared with that of the Kalman filter (KF) and extended Kalman filter (EKF). The method was demonstrated in the Qingyuan power station dam. The results show that the time-varying PIs based on trend data are smoother than those based on original data with better evaluation index scores. Also, the PIs are not affected by local anomalies. The proposed PIs are consistent with the actual measurements, and the UKF performs better than the KF and EKF. The approach has the potential to provide more reliable embankment safety assessments.

Mapping of Slope Failures on Highway Embankments using Electrical Resistivity Imaging (ERI), Unmanned Aerial Vehicle (UAV), and Finite Element Method (FEM) Numerical Modeling for Forensic Analysis

Highway Embankment Fill Slope is one of the significant components of transportation geo-infrastructures assets. Embankmets failure is a common problem that occurs due to various geotechnical, climatological, and environmental contributing parameters. Major influential factors include high temperature, high rainfall volume, and type of soil or a combination of all the above. For instance, when a slope built on high swell-shrinkage clay soil fails abruptly, it is due to the weakened self-retaining ability of the soil due to excess pore water pressure from high rainfall events. In Mississippi, rainfall is very intense, and lately, it is often characterized by aggressive showers. This rainfall generates significant soil strength losses that can endanger the safety and durability of embankments. Most embankments in the Jackson metro areas are constructed using Yazoo clay which is a typical High Swell-Shrinkage Clay Soil. These embankments have been found to experience shallow to deep failures a few years after construction due to the shrink-swell cycles during seasonal variations. These frequent failures have caused a significant maintenance problem for the Mississippi Department of Transportation (MDOT). Therefore, methods and approaches to evaluate embankment failures have been subject to careful examination by the MDOT by employing multiple investigations means, including Non-Destructive Testing (NDT) methods. To this end, in this study, Unmanned Aerial Vehicle (UAV), Electrical Resistivity Imaging (ERI), and Finite Element Method (FEM) numerical modeling were used to analyze shallow failure mechanisms within slopes. Several failed slopes located in the Jackson metro area in Mississippi were considered as references. The objective of the current study is to highlight the differences between pre and post-monitoring, evaluative, and analytic actions regarding embankments experiencing failure. During this study, four failed embankments were investigated using ERI and UAV to identify and locate the failed geometry, including slip surfaces. To better understand the failure mechanism, the identified embankments failure slip surfaces were numerically modeled using the FEM software package Plaxis 2D. Soil-strength parameters at failure were extracted through back calculation, and failure/slip surface depth was numerically characterized. The finding of this study helps post-embankments failure forensic evaluations significantly in terms of understanding failure mechanisms, identifying contributing failure parameters, better managing the decision-making process, and selecting an optimized stabilization technique.

Effectiveness of Stone and Deep Mixing Lime Columns on Stability of Embankments Constructed on Soft Consolidating Soil

One of the most common, effective and innovative ways to improve soft soil is to use stone columns or lime columns. An extensive study has been conducted to find the effectiveness of lime or stone columns to improve the settlement of embankments constructed over soft consolidating soil. There are very few studies to evaluate the effects of columns on embankment safety factor during foundation soil consolidation. This study examined the effectiveness of stone and lime columns on the embankment stability, both in terms of safety factor and settlement, which are determined at different intervals of time, during the foundation soil consolidation. Further, it was also investigated the effectiveness of stone and lime column composite system. In this numerical study, two-dimensional plane strain finite element method is used. This study shows that, stone columns are more effective than lime columns in reducing post-construction settlement and to accelerate consolidation process, whereas lime columns are observed to be more effective than stone columns in improving the safety factor after the embankment construction indicating that the usage of stone or lime columns is significantly affected by the purpose for which columns are used. In addition, it is also observed that the column effectiveness on safety factor is strongly influenced by the relative shear strength of embankment and foundation soils. Further, provision of stone and lime columns as a composite system performs better than providing only stone or lime columns.

Automatic recognition of earth rock embankment leakage based on UAV passive infrared thermography and deep learning

Leakage erosion is one of the most harmful driving factors causing river embankment breaches, particularly in flood season. However, manual patrol is the main way to find river embankment leakage presently, which badly hinders disaster prevention. To realize the efficient detection and automatic identification of embankment leakage, for the first time the strategy of UAV carried passive infrared thermography combined with transfer learning is introduced herein as an innovative approach to ensure embankment safety. Especially, the problem of embankment leakage identification is transformed into image classification. The main research objects in this study are slope leakage and piping, two of the most dangerous causes of embankment failure. To obtain sufficient images for model training, an open-air simulation platform which can simulate the slope leakage and piping under the actual service conditions of river embankment is established. A total of more than 500 infrared thermography experiments are conducted on the leakage simulation platform and then an infrared image database containing more than 10,000 images which contain various thermal anomaly areas generated by 6 classes of embankment leakage is established. Using these images and AlexNet-based transfer learning method, an image classification model with excellent performance is trained. This model has a classification accuracy of 94.90%, a small leakage missed rate of 0.64%, and a small false alarm rate of 2.65% on the test set. Moreover, before model deployment, visualization techniques such as t-SNE and Grad-CAM are adopted to provide interior insight of the model to ensure that the objects of concern on which the model makes its classification decisions are reasonable. Finally, field tests demonstrated strong feasibility of UAV carried infrared thermography combined with this well-trained model, and revels that the proposed leakage detection and recognition approach has good applicability and generalization.

Stability of Embankment Constructed on Soft Soil Treated with Soil–Cement Columns

The objective of this study was to investigate the effectiveness of soil–cement (SC) columns, provided either individually or in combination with lime columns, on the stability of embankment constructed on soft consolidating soil. The stability of the embankment was evaluated in terms of both the settlement and factor of safety at various time intervals during the consolidation. The effectiveness of columns was studied numerically using the two-dimensional plane strain finite element method. Settlement, excess pore water pressure and factor of safety were obtained at various time intervals. From the study, it was concluded that SC columns were effective in improving both the settlement and factor of safety of embankment throughout the consolidation of foundation soil. Provision of SC columns with lime columns was also effective in improving the stability of embankment. In addition, the stability of the embankment was affected by the arrangement of columns in the lime and SC composite system. The arrangement most effective to improve the settlement need not be the most effective system to improve the factor of safety after the construction of the embankment.

Effect of GGBS on Strength Characteristics and Stability of Pond Ash Mixed Soil Embankment

The increased usage of coal by thermal power plants results in enormous volumes of pond ash. Ground Granulated Blast Furnace Slag (GGBS) is produced in huge quantity in iron industries and is mostly utilised in the cement industry. Despite the fact that these industrial by-products have a wide range of applications, it is still conceivable to investigate the alternate mode for batch usage. The present study explores the effectiveness of GGBS in modifying the strength characteristics of a soil-pond ash mix. Pond ash was mixed with soil at 10%, 15%, 20%, and 25%, and strength behaviour were determined by analysing compaction characteristics, Unconfined Compressive Strength (UCS), bearing ratio behaviour, and shear strength parameters. The effect of GGBS addition in various amounts on the strength properties of pond ash-soil mix was also observed at various curing periods. Stability analysis was also conducted using limit equilibrium based GEOSLOPE software to evaluate the Factor of Safety (F) and stability of stabilized soil embankment. It was found from the test results that the addition of GGBS to the pond ash-soil mix improved the strength behaviours. With the inclusion of GGBS, the curing period was extended, which resulted in a substantial improvement in strength properties. Substantial improvement in factor of safety and stability of embankment was also observed by adding GGBS in pond ash-soil mix. Outcome of present study demonstrates an alternative approach for effective and safe utilization of GGBS and pond ash at optimum proportions.

Detect and identify earth rock embankment leakage based on UAV visible and infrared images

Leakage is one of the most common and harmful disease in earth rock river embankment. Timely detection and accurate identification of the leakage in flood season is of great significance to ensure the safety of river embankment. Existing detection technologies generally have the defects of large blind area, low efficiency and high operation cost. And as a result, manual visual observation is still the main means to find embankment leakage in flood season. In order to reduce the huge labor resources consumption and provide an efficient and cheap method for embankment leakage detection in flood season, a non-contact sensing mode of UAV equipped with visible and infrared cameras is introduced into river embankment leakage detection. A simple and efficient leakage identification method based on UAV infrared images is also proposed. Considering the limitations of single vision, a leakage region segmentation method based on infrared and visible image fusion is proposed. The application of the proposed methods is demonstrated on an actual river embankment, and the results show that the proposed strategy is feasible to identify embankment leakage and it has a great application prospect for embankment leakage detection in flood season.

Characteristics of the Interface between Bamboo Grids and Reinforced Soil of High-Filled Embankments in Loess Areas

There are a large number of high-filled and deep-dug highways in loess areas. The differential settlement between the filled and undisturbed soils is the main cause of damage. Bamboo grids are good reinforcement and flexural tensile materials for highway subgrades, and the properties of the interface between the bamboo grid and loess soil affect the safety and stability of embankments. First, the feasibility of bamboo grid application in high-filled embankments in loess areas was verified based on a durability analysis and test of the mechanical properties of bamboo. Then, a series of large-scale direct shear tests were carried out to determine the shear properties of the interface between bamboo grids and loess soils. The influential factors of vertical stress, shear rate, grid spacing, and compactness on the shear properties were studied, and the related mechanism was discussed. The results show that bamboo grids enhance the shear strength of loess soils more than geogrids under different vertical stresses because of the passive friction resistance between the vertical and horizontal ribs and soil particles, the bite force of particle skeletons, and the surface friction of grids. Bamboo grids enhance the stability and shear resistance of soils because of their good deformation performance, and thus, the shear rate effect within 7 mm/min can be negligible. The greater the relative compaction of the subgrade soil, the better the reinforcement effect owing to the greater cohesive force, greater internal friction angle, and better bite force. The variation in grid spacing changes the embedded effect of soil, side friction resistance, and size of the contact area. The shear resistance has an optimal value, which first increases and then decreases. Therefore, in practical applications, it is necessary to test the optimal bamboo grid spacing for a project.

A Simulation of Salt Transport in NaCl-Laden Soil Barrier to Control Subterranean Termites in an Earth Embankment

Subterranean termite activity can increase the hydraulic conductivity and water infiltration of filling soil, and therefore affects the stability of an earth embankment and subsequent safety. As a physical barrier for sustainable termite management, NaCl-laden soil barrier (NLSB) is a promising alternative for subterranean termite control in earth embankments. This novel technology can prevent tunneling and penetration of subterranean termites into the interior of an embankment and has been widely employed for more than 20 years in Zhejiang Province, China. The efficacy and longevity of NLSB depend on the long-term presence of NaCl concentration in soil barriers. The aim of this study is to develop an understanding of water flow and salt transport in NLSB based on the two-dimensional Richards’ equation and convection dispersion equation using the HYDRUS software package. Conceptual and numerical models of NLSB are modeled using scenario analysis according to water level fluctuations, saturated hydraulic conductivity, and rainfall infiltration conditions. Furthermore, the center and spread variance of a solute mass over a 100-year period are quantified using moment analysis. As flood frequency, saturated hydraulic conductivity, and rainfall infiltration flux increase, salt desalination in NLSB significantly increases. When the rainfall infiltration flux is 1% of the annual average rainfall, the total amount of salt transport and leaching can increase by 55%. Moreover, these results facilitate better long-term sustainable management of existing sites and optimal design of future NLSBs.

Experimental investigation on uniaxial compressive mechanical characteristics of red-sandstone containing single fissure after rainfall infiltration

The fissure flawed red-sandstone under dynamic rainfall infiltration is one of the key factors determining the safety and reliability of red-sandstone embankment and slope. However, there is still a lack of investigations considering the combined influence of rainfall infiltration and flaw geometry on the mechanical behavior of fissure flawed red-sandstone. Therefore, the effects of rainfall intensity, rainfall duration, as well as prefabricated fissure inclination angle on the uniaxial compressive mechanical behavior of red-sandstone containing a prefabricated fissure were investigated by rainfall infiltration and uniaxial compression tests. The results show that fissure inclination angle, rainfall intensity, and duration have significant influences on the axial stress-strain characteristics of the red-sandstone specimen under uniaxial compression. The quantitative expression of the unconfined compressive strength, peak strain, modulus with fissure inclination angle, rainfall intensity, and duration are obtained. The unconfined compressive strength, deformation modulus, and elastic modulus of the red-sandstone specimen present negative relationships with rainfall intensity and duration, while a positive trend is observed for its peak strain. The unconfined compressive strength, deformation modulus, and elastic modulus of the red-sandstone specimen attain the minimums when the prefabricated fissure inclination angle is 45°, while its peak strain reaches the maximum at this time. The ultimate failure modes, crack characteristics, and types of the red-sandstone specimen under uniaxial compression after rainfall infiltration are discussed according to the photographic monitoring in uniaxial compression tests. The meso-level failure mechanism of the red-sandstone specimen under uniaxial compression after rainfall infiltration is evaluated on the basis of the meso-morphology of the specimen’s fractured surface. The influences of prefabricated fissure inclination, rainfall intensity, and duration on the variations of the red-sandstone specimen’s crack growth angle under axial compression are also analyzed.

Geosynthetic-Encased Granular Columns Subjected to Vertical and Shear Loads

Granular columns are commonly used to support flexible structures over soft clay soils. The installation of such columns increases both the strength and stiffness of the ground. However, constructing these columns in clay soils having low cohesive strength of about 15 kPa is a challenge due to inadequate confinement. The columns may be encapsulated in geosynthetic tubes to enhance their constructability, strength and drainage properties. The geosynthetic encasement is also known to improve their performance under shear loading. This paper reviews the application of geosynthetic-encased granular columns for treatment of soft grounds. The design of these systems under vertical loads by two different methods is described in this paper. The performance of geosynthetic-encased granular columns under shear loads and the influence of geosynthetic encasement on the factor of safety of embankments supported on soft clay soils is discussed. The use of geosynthetic encasement of granular columns is seen to change the deep-seated foundation failure mechanism to toe failure mechanism.

Provision of Percolation Pits for Embankment Safety: A-State-of-Art-and-Review

An embankment is a vacillating wall of earth or concrete, which directs the river or flood water to its actual target and prevents farmlands. During heavy flood, water overtops the crest and silts clog sluice gate. This creates wave and extensive silt pressure on the wall. In order to avoid such situation, it needs to diverted floodwater through a water channel to a silt trap. Silts will settle in the silt trap and clean water will lend into the injection well passing through the multilayer of injection media. The floodwater is accommodated in a specially designed storage well accompanied with percolating cloak. The cleared water columns injected into the deeper layers of semi-impervious soil strata through the non-clogging percolating screens attached to the well. This diverts the water to percolates to deeper earth strata by capillary action and helps to recharge ground water. The paper aims on deliberating different eco-friendly design and construction technique of high raise embankment. Apart from this, an attempt has been made to showcase the increasing trends in research publication and activity in the area of eco-friendly construction practices to direct and absorb water without affecting the artesian spring.

ANALISIS STABILITAS TIMBUNAN DI ATAS KONSTRUKSI TIANG DAN GEOSINTETIK MENGGUNAKAN PROGRAM ELEMEN HINGGA

soft soil is a challenge for geotechnical engineer due to the characteristics of the soil that cause over settlement. Geosynthetic reinforcement is used on piles to correct undesirable soft soil characteristics. This thesis will use the BS 8006 methods and 3D software that use the finite element method to compare the geosynthetic tensile strength and how geosynthetic influences the embankment. The author will use the 3D software in the hope that it will produce a more accurate analysis compared to the 2D software. This thesis will compare the calculation of the geosynthetic tensile strength with the finite element method and the BS 8006 method. This is done because the calculation method BS 8006 does not take into account the subgrade in analyzing the geosynthetic tensile strength. This geosynthetic material has been proven to reduce slippage and channel load to the pile. This reinforcement of poles and geocyntetics can increase embankment safety factor by at least 0.35.

Deep-Seated Slope Stability Analysis and Development of Simplistic FOS Evaluation Models for Stone Column-Supported Embankments

Inclusion of stone columns in the underlain soft soil is one of the most prominent methods for improving the stability of embankments. The stone columns are encased with a geosynthetic material to further enhance the stability. The influence of this partial replacement of weak foundation soil with stone columns on the performance of embankments needs to be quantified. In this study, performance of ordinary stone column (OSC) and geosynthetic-encased stone column (GESC)–supported embankments is carried out using a three-dimensional finite element programme (PLAXIS3D). A parametric study was conducted to quantify the influence of various factors viz. spacing to diameter ratio (S/D), stiffness of encasement, cohesion of soil, friction angle of stone column and friction angle of embankment on the factor of safety against deep-seated failure. The results show that encasing the stone columns enhances the stability of embankments. Decreasing the column spacing (S/D) enhances the stability, reduces the excess pore pressure development and average settlement. Increase in geotextile encasement stiffness, cohesion of underlain soft soil, friction angle of stone column and friction angle of embankment improves the performance of embankments and also reduces the average settlement of the ground under embankment. Results of the parametric study were used to develop two types of data-driven models viz. multiple linear regression (MLR) and artificial neural networks (ANN) to simplify the evaluation of the factor of safety (FOS) of embankments. Among the two approaches, ANNs were able to predict the factor of safety values more accurately.

Farklı Malzemeler ve Geosentetiklerin Yol Dolgusu Güvenliğine ve Davranışına Etkileri

Bu çalışmada, doğal ve atık malzemelerin geri kazanımından elde edilen yeni malzemeler ile oluşturulmuş yol dolgusu modelleri sonlu elemanlar yöntemi kullanılarak analiz edilmiştir. Kumlu silt, kaya agregası, beton, cam gibi farklı malzemelerin yol dolgusuna etkileri incelenmiş ve atık liflerin yol dolgusunda kullanıldığı modellerin analiz sonuçları doğal koşullar ile karşılaştırılmıştır. Ayrıca farklı geosentetik donatı sayıları ile güçlendirilmeye çalışılan yol dolgusu modelleri için de hesaplamalar yapılmıştır. Böylece oluşturulan yol modelinin güvenlik sayısına farklı malzemelerin, liflerin ve geosentetik sayısının etkileri incelenmiştir. Yolun ani göçmesine karşı değerlendirmeler yapılarak, dolgu altındaki yeraltı suyundan kaynaklanacak konsolidasyon davranışının da etkileri farklı malzeme koşulları için karşılaştırılmıştır. Ayrıca, farklı malzemeler kullanılarak inşa edilen dolgularda yolun farklı bölgelerinde trafik yükünden oluşabilecek oturma farkları da değerlendirilmiş ve geosentetiğin etkileri de belirlenmeye çalışılmıştır. Sonuçlar incelendiğinde hem çevreci hem de daha verimli çözümler için değerlendirmeler yapılmıştır. Atık malzemelerin geri dönüşümü ile elde edilen malzemelerin, yol dolgularının stabilite ve güvenlikleri için önemli katkılar sağlayabileceği gözlenmiştir.

Ant colony optimization for slope stability analysis applied to an embankment failure in eastern India

The safety of road embankments is mainly assessed in the engineering practice by limit equilibrium analyses. Locating the critical slip surface of embankments and calculating the corresponding factor of safety is a crucial task. In this paper, the continuous ant colony optimisation algorithm is used to analyse the stability of slopes with non-circular slip surfaces. To illustrate the proposed procedure, one example from published literature and another engineering case study of a landslide at a road construction site in India is analysed. This latter study is supplemented by the results of geotechnical investigations performed before and after the failure of the embankment. The results demonstrate that the proposed technique identifies correctly the critical slip surface and can thus be used for engineering applications.

Design method for quantifying embankment safety against lateral spreading and determining contribution of basal reinforcements

This study proposes an analytical method for the calculation of the safety factor against lateral spreading in embankments, both for cases with and without basal reinforcement. Hence, a new limit equilibrium approach is presented based on the lower bound plasticity theorem, which allows the computation of the required distribution of stresses along presumed slip surfaces at the limit state. Comparing the required distribution of stresses with the available resistances, the safety factor in the absence of basal reinforcement is calculated. If the safety factor is unsatisfactory, basal reinforcement can be introduced and its contribution to stability quantified. The lower bound approach allows the computation of mobilized resistance along the reinforcement. Accordingly, the proposed method allows the calculation of the safety factor against lateral spreading for problems involving basal reinforcements. Finally, the proposed method is compared with well-established methods in literature. Results suggest that the proposed method is reliable, practical, and applicable to safe and economical designs.