Edina Koch

18037534700

Publications - 24

Flower fertilization optimization algorithm with application to adaptive controllers

Edina Koch Hazim Albedran Shaymaa Alsamia

Publication Name: Scientific Reports

Publication Date: 2025-12-01

Volume: 15

Issue: 1

Page Range: Unknown

Description:

This article presents the Flower Fertilization Optimization Algorithm (FFO), a novel bio-inspired optimization technique inspired by the natural fertilization process of flowering plants. The FFO emulates the behavior of pollen grains navigating through the search space to fertilize ovules, effectively balancing exploration and exploitation mechanisms. The developed FFO is theoretically introduced through the article and rigorously evaluated on a diverse set of 32 benchmark optimization problems, encompassing unimodal, multimodal, and fixed-dimension functions. The algorithm consistently outperformed 14 state-of-the-art metaheuristic algorithms, demonstrating superior accuracy, convergence speed, and robustness across all test cases. Also, exploitation, exploration, and parameter sensitivity analyses were performed to have a comprehensive understanding of the new algorithm. Additionally, FFO was applied to optimize the parameters of a Proportional-Integral-Derivative (PID) controller for magnetic train positioning—a complex and nonlinear control challenge. The FFO efficiently fine-tuned the PID gains, enhancing system stability, precise positioning, and improved response times. The successful implementation underscores the algorithm’s versatility and effectiveness in handling real-world engineering problems. The positive outcomes from extensive benchmarking and practical application show the FFO’s potential as a powerful optimization tool. In applying multi-objective PID controller parameter optimization, FFO demonstrated superior performance with a sum of mean errors of 190.563, outperforming particle swarm optimization (250.075) and dynamic differential annealed optimization (219.629). These results indicate FFO’s ability to achieve precise and reliable PID tuning for control systems. Furthermore, FFO achieved competitive results on large-scale optimization problems, demonstrating its scalability and robustness.

Open Access: Yes

DOI: 10.1038/s41598-025-89840-1

Flower Pollination Algorithm on optimal design of space trusses

Edina Koch M. Movahedi Rad Shaymaa Alsamia

Publication Name: International Review of Applied Sciences and Engineering

Publication Date: 2025-10-13

Volume: 16

Issue: 3

Page Range: 418-427

Description:

Abstract: This study assesses the performance of four nature-inspired optimization algorithms—Dynamic Differential Annealed Optimization (DDAO), Flower Pollination Algorithm (FPA), Firefly Algorithm (FF), and Particle Swarm Optimization (PSO) for achieving optimal space truss design. The aim is to minimize the structural weight of three benchmark trusses (10-bar, 25-bar, and 72-bar) while meeting stress and displacement constraints. The key contribution of this work is the first systematic evaluation of FPA in space truss optimization, demonstrating its greater effectiveness in obtaining optimal or near-optimal solutions with faster convergence and higher stability compared to PSO and FF. The results also highlight the limitations of DDAO in handling constrained engineering problems. Findings confirm that FPA and FF are highly effective for structural optimization, offering robust solutions with minimal computational cost. These insights contribute to advancing metaheuristic-based structural design, supporting the adoption of FPA in large-scale optimization problems.

Open Access: Yes

DOI: 10.1556/1848.2025.00958

Investigation of CO2 Emission Concerning Levee Reinforcement Technologies

Edina Koch Zoltán Major Szigeti Cecília

Publication Name: Lecture Notes in Civil Engineering

Publication Date: 2025-01-01

Volume: 580 LNCE

Issue: Unknown

Page Range: 1-10

Description:

Flooding is one of the primary causes of losses from natural disasters in numerous regions worldwide, surpassing all other types of natural hazards in terms of damage. In recent decades, flood damage has been significantly severe due to the increase in the frequency and intensity of floods. Considering that levees are built for an established design life, it is essential to consider potential changes in loads due to atmospheric climate change. Climate variability may affect hydraulic loading and soil eroding with significant precipitation or during drought or high wind conditions. These atmospheric changes over time may affect the structural integrity of the levee. The dominating failure modes for typical ground conditions along rivers are slope stability, overtopping, through seepage, and underseepage. Several technologies can be applied to prevent levee failure, strengthen the levee, avoid overtopping or internal erosion, and ground subsidence due to changing groundwater. The most common ones are concrete columns, sheet piles, geosynthetics, and deep mixing using different binders. However, these technologies come out to be costly, in terms of materials. Moreover, the primary material of these interventions is cement. Nowadays, it is accepted that the cement industry is one of the two largest producers of carbon dioxide (CO2). The Sustainable Development Goals (SDGs) provide comprehensive guidelines for promoting sustainable development in terms of environmental, social, and economic dimensions in all sectors of the economy, including civil engineering. The study outlines the procedure to calculate the carbon dioxide emissions of different technologies for levee reinforcement. Considering a simple scenario, the technical suitability of the investigated technologies is analyzed, and the carbon dioxide emission is analyzed separately.

Open Access: Yes

DOI: 10.1007/978-981-96-1873-6_1

Adaptive Exploration Artificial Bee Colony for Mathematical Optimization

Edina Koch Hazim Albedran Shaymaa Alsamia R. P. Ray

Publication Name: AI Switzerland

Publication Date: 2024-12-01

Volume: 5

Issue: 4

Page Range: 2218-2236

Description:

The artificial bee colony (ABC) algorithm is a famous swarm intelligence method utilized across various disciplines due to its robustness. However, it exhibits limitations in exploration mechanisms, particularly in high-dimensional or complex landscapes. This article introduces the adaptive exploration artificial bee colony (AEABC), a novel variant that reinspires the ABC algorithm based on real-world phenomena. AEABC incorporates new distance-based parameters and mechanisms to correct the original design, enhancing its robustness. The performance of AEABC was evaluated against 33 state-of-the-art metaheuristics across twenty-five benchmark functions and an engineering application. AEABC consistently outperformed its counterparts, demonstrating superior efficiency and accuracy. In a variable-sized problem (n = 10), the traditional ABC algorithm converged to 3.086 × 106, while AEABC achieved a convergence of 2.0596 × 10−255, highlighting its robust performance. By addressing the shortcomings of the traditional ABC algorithm, AEABC significantly advances mathematical optimization, especially in engineering applications. This work underscores the significance of the inspiration of the traditional ABC algorithm in enhancing the capabilities of swarm intelligence.

Open Access: Yes

DOI: 10.3390/ai5040109

Applying clustered artificial neural networks to enhance contaminant diffusion prediction in geotechnical engineering

Edina Koch Shaymaa Alsamia

Publication Name: Scientific Reports

Publication Date: 2024-12-01

Volume: 14

Issue: 1

Page Range: Unknown

Description:

This paper introduces a novel approach using Clustered Artificial Neural Networks (CLANN) to address the challenge of developing predictive models for multimodal dataset with extreme parameter values. The CLANN method strategically decomposes the dataset, derived from Finite Element Analysis (FEA), into clusters, each representing distinct diffusion behaviors, and applies specialized neural networks within these clusters. The CLANN model was rigorously evaluated and demonstrated superior accuracy and consistency compared to traditional methods such as the Adaptive Neuro-Fuzzy Inference System (ANFIS) and fuzzy expert systems. While these conventional models struggled to capture the full range of diffusion dynamics, particularly under extreme conditions, CLANN consistently provided predictions that closely aligned with the actual FEA data across all scenarios. The versatility of the CLANN approach extends beyond its application to soil contamination. Its ability to handle complex, multimodal datasets suggests that this methodology can be generalized to a wide range of scientific and engineering problems characterized by similar data structures. This makes CLANN not only a powerful tool for geotechnical engineers but also a promising framework for broader applications where traditional models fall short. The findings of this study pave the way for more accurate, reliable, and adaptable predictive modeling in diverse domains, enhancing our ability to manage and mitigate environmental and engineering challenges.

Open Access: Yes

DOI: 10.1038/s41598-024-79983-y

Random forest regression on pullout resistance of a pile

Edina Koch Shaymaa Alsamia

Publication Name: Pollack Periodica

Publication Date: 2024-10-16

Volume: 19

Issue: 3

Page Range: 28-33

Description:

This research aims to study the pullout resistance of a helical pile using three methods of machine learning techniques, which are: random forest regression, support vector regression, and adaptive neuro-fuzzy inference system, based on experimental results of a helical pile. The performance of these three techniques has been d compared and the results show that random forest algorithm has best performance than neuro-fuzzy inference system and support vector technique. The results show that machine learning considered a good tool in terms of estimating the pullout resistance of helical piles in the soil.

Open Access: Yes

DOI: 10.1556/606.2024.01052

Dynamic Analysis of Geosynthetic-reinforced Pile-supported Embankment for a High-Speed Rail

Edina Koch Rashad Alsirawan

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2024-01-01

Volume: 21

Issue: 1

Page Range: 31-50

Description:

Geosynthetic-Reinforced-Pile-Supported (GRPS) embankments are a trustworthy option ideal to support the railways over soft soils. They are widely used for the time-bound infrastructure projects. The majority of earlier research concentrated on the analysis of the GRPS embankments under static loads while the studies on the behavior of these constructions under dynamic loads are scarce. The fundamental purpose of this study has been to better comprehend the dynamic behavior of GRPS embankments in terms of stresses and settlements distribution via 3D modeling employing the finite element method (FEM). The advanced constitutive model of Hardening soil with small-strain stiffness was utilized to simulate the behavior of the soils under dynamic loads and the train load was modeled according to the recommendations of LM71 Eurocode. The results indicate to the contribution of the piles and geosynthetic reinforcement in the decrease of the settlements. The behavior of settlements and stresses under static and dynamic loads is similar. The load efficiency of the piles decreases during the passage of the train remarkably. The train speed affects obviously on the behavior of the GRPS embankment.

Open Access: Yes

DOI: 10.12700/APH.21.1.2024.1.3

Impact Assessment of Railway Bridge Construction Schedule, based on 3D Geotechnical Finite Element Modeling

Edina Koch R. P. Ray

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2024-01-01

Volume: 21

Issue: 1

Page Range: 187-205

Description:

The increasing demand for high-speed railways has risen, to solve the "age-old" problem of bridge abutments, the step between the backfill and the bridge deck. Examples prove that inadequate technical solutions can generate damage that may require long-term speed restrictions or lead to short maintenance cycles, significantly increasing the total cost of ownership. The problems associated with the transition zones require complex analysis. The complex interaction of structural elements with different stiffnesses and different dynamic behavior varies over time due to the time-dependent behavior of the soil, and in addition, a bridge deck and its connecting elements can be constructed in several sequences. This study investigated a typical single-span railway bridge and its soil environment using PLAXIS 3D geotechnical finite element software. Different constitutive soil models were used to approximate the behavior of the bridge and the connecting elements. To model the soil behavior, the HS-small constitutive model was implemented. Loads of the structure are transferred onto the subsoil by 60 cm diameter piles modeled as embedded piles. Six different construction schedules were analyzed using time-domain analyses. The importance of high-speed railways was highlighted, and a 250 km/h train speed was applied, using dynamic analysis. The study focuses on the effect of different construction schedules on settlement, consolidation time, the behavior of the transition, and the substructure movements. The results of this study show that geotechnical approaches by themselves are not enough to solve the problem of the transition zone, highlighting the collaboration of geotechnical, structural and railway engineers.

Open Access: Yes

DOI: 10.12700/APH.21.1.2024.1.12

Change in Stiffness of Reinforced Concrete Tunnel Walls and Its Effect Under Fire Load

Edina Koch Éva Lublóy Zoltán Major

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 342-350

Description:

This article uses the knowledge gained from tunnel fires to address the structural analysis of tunnel walls during fire exposure. The designing at normal temperature and its theoretical background are discussed in the literature. As these books did not yet deal with the issue of fire protection designing, we tried to supplement the existing theoretical knowledge with the knowledge provided by the relevant standards for reinforced concrete tunnel walls. In addition, we have tried to add our own individual ideas to the theory where we felt that there were gaps. The theoretical summary has been compiled in such a way that it can be easily transferred and applied to everyday practice. In this article, we discuss in detail the calculation of the internal forces in tunnel walls during fire exposure. Due to space constraints, the issue of designing at normal temperatures is only touched upon in this article, limiting it to the knowledge available in the literature. Since finite element modelling has become a commonly used technique in tunnel design since the 1970s, we use its potential to investigate the effects of earth pressure and surface loads on the tunnel walls during fire and their changes, using specific software for geotechnical design. In accordance with the limitations of the scope, the determination of the equivalent thickness and the modulus of elasticity of the tunnel wall is also presented in order to determine the internal forces during the fire action.

Open Access: Yes

DOI: 10.3233/ATDE240565

Finite Element Analysis of Microtunneling Under a Railway Track

Edina Koch Zoltán Major Shaymaa Alsamia

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 351-357

Description:

Microtunneling is a trenchless construction method used to install pipelines beneath highways, railroads, runways, harbors, rivers, and environmentally sensitive areas. For railway lines, the primary objective of the method is to address the challenges posed by the installation of utilities without disrupting rail operations. The aim is to minimize the impact on railway services, ensuring the uninterrupted flow of transportation while facilitating essential infrastructure development. Traditional excavation methods often involve significant ground disturbance and pose risks to the stability of the railway track, leading to service interruptions and safety hazards. Microtunneling, on the other hand, offers a non-disruptive alternative by utilizing advanced tunneling equipment that minimizes ground settlement and vibration, reducing the risk of damage to the railway structure. The technique involves the use of remotely controlled boring machines to excavate tunnels with precision, allowing for the installation of pipelines or other utilities with minimal impact on the railway infrastructure above. The aim is to achieve a seamless integration of new underground utilities while maintaining the structural integrity and operational functionality of the railway line. Furthermore, microtunneling under a railway line contributes to sustainable development by minimizing the environmental footprint associated with construction activities. The reduced excavation and disturbance to the surrounding environment lead to lower levels of noise, dust, and disruption, aligning with modern principles of environmentally conscious infrastructure development. In this study, the installation of a sewage pipeline constructed by microtunneling under an existing railway track is investigated using geotechnical and structural FEM.

Open Access: Yes

DOI: 10.3233/ATDE240566

Experimental and Numerical Investigation of Geosynthetic-Reinforced Pile-Supported Embankments for Loose Sandy Soils

Edina Koch Rashad Alsirawan Ammar N. Alnmr

Publication Name: Buildings

Publication Date: 2023-09-01

Volume: 13

Issue: 9

Page Range: Unknown

Description:

This research focuses on advancing the geosynthetic-reinforced pile-supported embankment technology over loose sandy soil. A small-scale laboratory model supported by floating piles and a geotextile layer was constructed, and a numerical model was validated against laboratory measurements. This study aims to achieve a more uniform distribution of the load over all piles of the system via a parametric study that analyzes the influence of embankment fill material, horizontal reinforcement scenarios, pile cap shape, and pile type. The results demonstrate that using embankment fill with high cohesion and internal friction properties leads to a significant reduction of 46% and 37% in maximum settlements, respectively, and similarly, results in a noteworthy reduction of 48% and 50% in differential settlements. The incorporation of two geotextile layers contributes to a reduction of up to 30% in maximum settlement. The utilization of plus-shaped caps in small areas, with an area equal to three times the cross-sectional area of the pile, has been substantiated as the preeminent approach for the reduction of settlements. Piles with caps also present better behavior regarding differential settlements compared to longer piles and piles with bigger diameters under the same volume condition.

Open Access: Yes

DOI: 10.3390/buildings13092179

Comparative study of metaheuristics on optimal design of gravity retaining wall

Edina Koch Shaymaa Alsamia Hanaa Shihab Hamadi

Publication Name: Pollack Periodica

Publication Date: 2023-07-11

Volume: 18

Issue: 2

Page Range: 35-40

Description:

Retaining walls are typical geotechnical engineering applications analyzed extensively in the literature. However, the optimal design of these walls is still unsolved due to the optimization problem's complexity and the unrecognized best solver that can be used. Most similar works present a single optimizer for this problem. This work used six metaheuristics to formulate and solve the optimal gravity retaining wall problem design. The comparative study was achieved among particle swarm optimization, grey wolf optimizer, artificial bee colony, dynamic differential annealed optimization, fertilization optimization algorithm, and whale optimization algorithm. The problem and its results were discussed in detail within the respective sections.

Open Access: Yes

DOI: 10.1556/606.2023.00826

Proposed Method for the Design of Geosynthetic-Reinforced Pile-Supported (GRPS) Embankments

Edina Koch Rashad Alsirawan Ammar N. Alnmr

Publication Name: Sustainability Switzerland

Publication Date: 2023-04-01

Volume: 15

Issue: 7

Page Range: Unknown

Description:

Soft soils with unfavorable properties can be improved using various ground-improvement methods. Among these methods, geosynthetic-reinforced pile-supported (GRPS) embankments are considered a reliable option for challenging ground conditions and time-bound projects. Nevertheless, the intricate load transfer mechanism of the GRPS embankment presents challenges due to the multiple interactions among its components. To overcome the limitations of current design methods that do not fully account for all interactions, a simplified design method has been developed for GRPS embankments. This method uses numerical analysis to predict pile load efficiency and geosynthetic tension. In this study, a validated model of the GRPS embankment, which incorporates certain simplifications for design purposes, was adopted. Based on this simplified model, a database of load efficiency and geosynthetic tension was collected to derive the design equations. The design method employed six parameters, namely, pile cap width, pile spacing, embankment height, oedometric modulus of the subsoil, geosynthetic stiffness, and embankment fill unit weight. The design process utilized Plaxis 3D and Curve Expert software. The results showed reasonable agreement between the findings of the proposed design method and the field measurements of eight case studies.

Open Access: Yes

DOI: 10.3390/su15076196

EVALUATION THE BEHAVIOR OF PULLOUT FORCE AND DISPLACEMENT FOR A SINGLE PILE: EXPERIMENTAL VALIDATION WITH PLAXIS 3D

Edina Koch Shaymaa Alsamia

Publication Name: Kufa Journal of Engineering

Publication Date: 2023-04-01

Volume: 14

Issue: 2

Page Range: 105-116

Description:

This study conducted an experimental and numerical investigation to examine the pullout behavior of a single pile in sand soil with a specific density. The soil testing model was constructed to simulate real-world geotechnical applications where the soil is subjected to varying pullout forces. The experimental setup involved measuring vertical displacement corresponding to different values of pullout forces. The results were then compared to numerical results obtained from a PLAXIS 3D model with HS-small. The experimental and numerical results showed good agreement, demonstrating the effectiveness of the numerical model in simulating real-world geotechnical applications. The study provides valuable insights into the pullout behavior of a pile in soil with specific density and can be used to improve the design and construction of geotechnical structures. The difference between experimental results and numerical predictions was in acceptable values.

Open Access: Yes

DOI: 10.30572/2018/KJE/140207

Investigating the Ecological Footprint of Deep Mixing

Edina Koch Zoltán Major Szigeti Cecília

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 349-354

Description:

In railway construction practice, we are increasingly faced with the problem of having to pass our new lines through areas with unfavorable subsoil conditions or with the need to reinforce the substructure of our existing lines due to increasing traffic demands (speed, axle load). The low strength, high compressibility, and low permeability of unfavorable subsoil will result in stability problems and prolonged consolidation with extremely high settlements, respectively. One of the effective technologies to counter the geotechnical problems is the deep mixing. The technology requires the addition of a binder (cement, lime) to the local soils. These materials have a high installed CO2 emission, thus significantly increasing the ecological footprint of infrastructure development. Due to the increasing demands on reducing CO2 emissions, secondary raw materials, e.g., fly ash or slag, have been increasingly prioritized. The study reports the methodology for calculating the ecological footprint of deep-mixing as an embankment foundation. Based on a simple case, the effect of different cement content (5 and 8%), and the application of slag and fly ash as a secondary raw material is analyzed, and the ecological footprint is calculated separately. The results show that the ecological footprint of deep mixing can be drastically reduced; under the conditions of the study, the reduction compared to clean cement is 40% for slag stabilization and 50% for fly ash.

Open Access: Yes

DOI: 10.3303/CET23107059

Sustainable levee construction along the Danube River

Edina Koch M. Marchi R. P. Ray L. Tonni

Publication Name: Proceedings of the International Congress on Environmental Geotechnics

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: 399-408

Description:

Nowadays' changing weather conditions and the resulting increasing flood levels make flood protection improvement essential. In Hungary, in the Szigetköz floodplain area, a complex water resources management unit of the Upper part of the Danube River, the rehabilitation of the water levels, and the setting back of the settled low and middle water levels had become necessary. It has been achieved by relocating the estuary of the Mosoni-Danube River and constructing a complex water control structure. A new ~1.5 km long levee connects to the structure. Due to a large volume of fine-grained blanket material on the site, the possibility arose to build a section of the levee using the blanket material without applying a cut-off wall to prevent water flow through the levee. The geotechnical parameters of the available local material were based on a complex site investigation program. According to the results of the field and laboratory tests, the blanket layer was suitable as fill material and could be compacted to the required 90% degree of compaction using standard machinery and procedures. Plaxis 2D software using fully coupled flow-deformation analysis, imitating the previously registered flood waves, modeled seepage and stability behaviour to evaluate the ultimate limit states of the levee constructed from the blanket material. The analysis proved the adequacy of the blanket material, avoiding the necessity for a barrier within the embankment. The use of local blanket material as fill eliminated the need to excavate and transport additional material, reducing environmental impact, shortening construction time, and saving costs on the project.

Open Access: Yes

DOI: 10.53243/ICEG2023-396

The finite element modeling of rigid inclusion-supported embankment

Edina Koch Rashad Alsirawan

Publication Name: Pollack Periodica

Publication Date: 2022-01-01

Volume: 17

Issue: 2

Page Range: 86-91

Description:

The design of supported embankments on soft soil is a common challenge for civil engineers. This article aims to evaluate the performance of three advanced constitutive models for predicting the behavior of soft soils, i.e., hardening soil, hardening soil model with small-strain stiffness, and soft soil creep. A case study of a rigid inclusion-supported embankment is used for this purpose. Plaxis 3D program was adopted to predict the settlements in subsoil layers and vertical stresses in the load transfer platform. Comparison between field measurements and result of Plaxis 3D modeling was performed. Results demonstrate that soft soil creep model yields predictions in a good agreement with the field measurements, while hardening soil small strain model gives slightly worst predictions.

Open Access: Yes

DOI: 10.1556/606.2021.00504

Finite element analysis of bridge transition zone for investigating the effect of moving loads

Edina Koch

Publication Name: 17th European Conference on Soil Mechanics and Geotechnical Engineering Ecsmge 2019 Proceedings

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The problem of track-bridge interaction and its modeling issues have increasingly been emphasized and highlighted due to the presence of high-speed rails. The quality criteria for high-speed rail lines must be stricter than those for conventional rail lines to assure passenger comfort and safety. Experience shows that in transition zones when a train rides from an embankment onto a stiff structure, such as a bridge, tunnel or culvert, an abrupt change occurs in the support stiffness possibly inducing differential settlements. Examples prove that inadequate technical solutions can generate damage that may require long term speed restrictions or lead to short maintenance cycles, significantly increasing the total cost of ownership. The problems associated with the transition zones require complex analysis. The author reports the results obtained by the investigation of a 3D numerical model of a bridge transition zone by means of an advanced constitutive model and time domain analysis. The mechanical behavior of a railway bridge and its soil environment is presented in the study with special regards to factors like train speed, embankment height and the settlement differences apparently developing in the transition zone.

Open Access: Yes

DOI: 10.32075/17ECSMGE-2019-0137

Modeling of railway transition zones under dynamic loading

Edina Koch P. Hudacsek

Publication Name: Icsmge 2017 19th International Conference on Soil Mechanics and Geotechnical Engineering

Publication Date: 2017-01-01

Volume: 2017-September

Issue: Unknown

Page Range: 1369-1372

Description:

Transition zones of railway tracks are intended to provide a smooth transition of the riding train, minimizing the effect of the discontinuities that exist along the track. When a train rides from an embankment onto a stiff structure, such as a bridge, tunnel or culvert, an abrupt change in the support stiffness occurs possibly inducing differential settlements. This in long term can yield to the degradation of the tracks and foundations in the transition zones. The differential settlement is especially problematic for high speed rail infrastructure as the "bump" at the transition is accentuated at high speeds. A number of techniques have been proposed or implemented to provide gradual stiffness transition at the problem zones, such as methods to ensure gradually changing pad stiffness, application of long sleepers or installation of auxiliary rails in the transition zone. The problems associated with the transition zones require a complex analysis. For efficient modeling of the mechanisms resulting in gradual line deteriorations in the transition zones the understanding of the 3D and dynamic effects associated with the problem seems to be essential. To enhance our understanding regarding the problem a 3D numerical model has been developed and presented for time domain analysis.

Open Access: Yes

DOI: DOI not available

Numerical modeling of levees according to Eurocode 7

Edina Koch None Wolf R. Szepeshazi

Publication Name: Geotechnical Engineering for Infrastructure and Development Proceedings of the Xvi European Conference on Soil Mechanics and Geotechnical Engineering Ecsmge 2015

Publication Date: 2015-01-01

Volume: 4

Issue: Unknown

Page Range: 2019-2024

Description:

In many European countries, flood protection and development of levees has a great importance due to ever-increasing flood levels. The final version of Eurocode 7 includes three chapters that govern the levee design. They suggest mainly conventional concepts and principles but do not provide a comprehensive design methodology for use in practice as it was formerly given in the national standards. Analytical seepage calculations used in present-day practice are based on numerous simplifying assumptions, so they often do not simulate actual conditions. The method of slices, generally used for stability analysis, is sometimes criticized for theoretical reasons. Recently, development of numerical modeling and software have employed coupled finite element analysis for mechanical and hydraulic problems. A single FEM model can apply to levee design, stability analysis, underseepage and through seepage, and analysis of seepage forces. This paper reports research results gained about modeling levees by Plaxis to meet the requirements of the Eurocode 7.

Open Access: Yes

DOI: DOI not available

Laboratory tests and numerical modeling for embankment foundation on soft chalky silt using deep-mixing

Edina Koch R. Szepeshazi

Publication Name: 18th International Conference on Soil Mechanics and Geotechnical Engineering Challenges and Innovations in Geotechnics Icsmge 2013

Publication Date: 2013-01-01

Volume: 3

Issue: Unknown

Page Range: 2521-2524

Description:

The deep-mixing is nowadays world-wide accepted method as a ground treatment technology to improve the permeability, strength and deformation properties of soils. Binders, such as lime or cement are mixed in-situ with the soil by rotating mixing tools. The method is undergoing rapid development, particularly with regard to its range of applicability, cost effectiveness and environmental advantages. The paper describes the results of laboratory tests on chalky silt samples mixed with cement of different content. The influence of the different mixing parameters on the unconfined compression strength and deformation modulus is shown and evaluated. Typical results of the laboratory tests were used in numerical modeling with PLAXIS 3D as input parameters to study the behavior of a 4 m high embankment constructed on this soil improved by deep mixed columns with different spacing and diameters. The parameters of the soil improvement technique were analyzed to study their influence on the settlement and the stability of the embankment. The trends of the calculation outputs are shown and evaluated.

Open Access: Yes

DOI: DOI not available

Behaviour of transdanubian clay under unloading and reloading

Edina Koch

Publication Name: Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering the Academia and Practice of Geotechnical Engineering

Publication Date: 2009-12-01

Volume: 1

Issue: Unknown

Page Range: 463-465

Description:

In recent years, in the field of geotechnical design, software based on FEM has come to the front. Advanced computer programs make it possible to use more developed soil models besides the most current elastic-plastic Mohr-Coulomb model. By using these computer programs, nonlinear behaviour of the soil can be followed better, even in the case of more complicated load events. Among the constitutive models incorporated in the commercial software the Hardening Soil Model (HS) and Soft Soil Model (SS) are the most promising ones. Observations and experience gained in tunnel construction, deep open excavation or preloaded embankment prove that with these soil models reality can be followed more accurately, especially in cases where unloading and reloading are present. In order to produce the software input parameters, in case of more complicated soil model, more demanding laboratory tests are needed. In case of HS model one of the basic demands is to determine the power for stress-level dependency of stiffness (m), tangent stiffness for primary oedometer loading (E oed ref) and unloading/reloading stiffness (E ur ref). The paper focuses on the behaviour of transdanubian clay common in Hungary. Sampling, laboratory investigations and evaluation aimed to determine the input parameters for the HS are described. Results based on a number of oedometric tests accomplished with unloading and reloading proved to be adequate for the computational purposes. © 2009 IOS Press.

Open Access: Yes

DOI: 10.3233/978-1-60750-031-5-463

Input parameters of transdanubian clay for the hardening soil and soft soil models

Edina Koch

Publication Name: Pollack Periodica

Publication Date: 2009-04-01

Volume: 4

Issue: 1

Page Range: 93-104

Description:

In recent years, finite element modeling has become an important design tool. Advanced programs make it possible to use more complex soil models in addition to standard elasto-plastic models with Mohr-Coulomb failure criteria. These new models can follow nonlinear behavior and complicated loading sequences. The two most promising new models are: the Hardening Soil Model (HS) and the Soft Soil Model (SS). This paper focuses on the behavior of Transdanubian Clay, common in Hungary. Sampling, laboratory testing, and evaluation of data aiming at determining parameters for HS and SS models are described. Results based on oedometer tests using unloading/reloading sequences proved to be adequate for input to these models. © 2009 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.1.10

Monitoring of embankment construction processes

Edina Koch

Publication Name: Pollack Periodica

Publication Date: 2007-04-01

Volume: 2

Issue: 1

Page Range: 89-100

Description:

Nowadays more and more engineering structures are constructed on soft soils of low strength. High compressibility, low permeability and liability to secondary compression of these soils can result in long-term settlements and a menace with critical situations when the construction deadlines are tough. To cope with these problems several technologies have recently been developed in the embankment construction practice. Staged construction, over-filling, vertical drainage, stone columns, dynamic compaction - all of them often combined successfully with geosynthetics - are preferred to the previously predominant technology of soil replacement. Nevertheless, common design methods often do not balance properly the structural modeling, computation, economical and construction aspects. This is why a correct design may become a subject of reconsideration and modification in specific circumstances. There remains a room for innovative approaches, when conventional solutions are used. Two examples seem to prove that construction combined with monitoring may tum out to be good compromises. © 2007 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/Pollack.2.2007.1.8