Ammar N. Alnmr

57976842000

Publications - 20

Comparative Analysis of Foundation Systems in Expansive Soil: A Three-Dimensional Model Approach to Moisture Diffusion and Volume Changes

Ammar N. Alnmr Mounzer Omran Alzawi R. P. Ray

Publication Name: Geotechnical and Geological Engineering

Publication Date: 2024-11-01

Volume: 42

Issue: 8

Page Range: 7935-7961

Description:

This study compares the performance of various foundation systems in expansive soils, such as mats, granular anchor piles, and concrete piles. Expansive soils experience volumetric changes due to moisture fluctuations, which can lead to structural damage. Abaqus software, in conjunction with the SCV approach, is used to analyze soil-foundation interactions. A custom subroutine enhances simulation accuracy by incorporating empirical data on unsaturated clay behavior, matric suction, and variations in effective stress. The method’s accuracy is validated by comparing simulation results to field and laboratory experiments. The findings indicate that increasing the applied load on mats decreases overall heave but increases the differential heave. Additionally, higher soil permeability dereases the differential heave of mats. Granular anchor piles outperform concrete piles by more than 50% in highly expansive soils, suggesting a preference for these foundations. This study provides insights into the behavior of expansive soils, which will assist engineers in designing resilient foundation systems for structures.

Open Access: Yes

DOI: 10.1007/s10706-024-02959-2

Compressibility of expansive soil mixed with sand and its correlation to index properties

Rashad Alsirawan Ammar N. Alnmr Mounzer Omran Alzawi R. P. Ray

Publication Name: Heliyon

Publication Date: 2024-08-15

Volume: 10

Issue: 15

Page Range: Unknown

Description:

Prior research has primarily focused on Atterberg limits, void ratios, and/or water content, often disregarding the impact of coarse material percentage in the soil, which significantly affects compressibility behavior. This paper examines the effects of sand content, initial degree of saturation, and initial dry unit weight on the compressibility behavior of expansive soils. Ninty-six oedometer tests were performed in order to accurately predict the compressibility behavior of expansive soils. The previous studies have attempted to correlate compressibility with different index properties separately, but no single study has taken into consideration all properties influencing compressibility behavior, especially for expansive soils. The findings show that compressibility is greatly influenced by the sand content, initial degree of saturation, and initial dry unit weight. Increasing the initial dry unit weight specifically lowers the compression index and permeability while raising the recompression index for the same percentage of added sand. Moreover, since swelling reduces with increasing initial saturation, raising the saturation degree also lowers the permeability, recompression index, and compression index. The results indicate that a sand content of more than 30 % is recommended for achieving desired properties in expansive clayey soil. This is a result of sand taking the dominant role in the soil mixture, which lowers soil suction and improves soil properties by reducing swelling, permeability, and compressibility. Symbolic regression equations were created to predict the compression and recompression indices, outperforming previous models in accurately predicting the compressibility behavior of expansive soils, considering the percentage of sand. The validation of these equations demonstrates their predictive capabilities.

Open Access: Yes

DOI: 10.1016/j.heliyon.2024.e35711

Innovations in Offshore Wind: Reviewing Current Status and Future Prospects with a Parametric Analysis of Helical Pile Performance for Anchoring Mooring Lines

Ammar N. Alnmr Mais Mayassah

Publication Name: Journal of Marine Science and Engineering

Publication Date: 2024-07-01

Volume: 12

Issue: 7

Page Range: Unknown

Description:

This study examines the current status and future potential of the offshore wind sector. Offshore wind is pivotal in transitioning to a low-carbon society and meeting rising energy demands, despite being capital-intensive. The industry aims to develop larger-scale wind farms in deeper ocean locations, with projections indicating significant cost reductions. To explore deeper ocean areas, specialized foundations like floating platforms moored to the seabed are required. This study proposes helical piles anchored in the seabed as a method to secure mooring lines. Using Plaxis 3D, a parametric examination was conducted on helical piles with two plates: one fixed at the pile’s toe and the other varying in position between 0.5 and 13 m from the seabed surface. Load inclination angles (0, 20, 40, and 60 degrees) were used to simulate mooring line loads. Results indicate the optimal Zh/Z ratios for maintaining load-bearing capacity and stability: 0.12 (10 mm movements), 0.22 (25 mm), and 0.26 (50 mm) for small shaft diameters; and 0.34 (10 mm), 0.38 (25 mm), and 0.46 (50 mm) for large shaft diameters. These findings highlight the importance of specific load inclination angles based on shaft diameter and allowable movement for effective performance.

Open Access: Yes

DOI: 10.3390/jmse12071040

Investigating the Impact of Varying Sand Content on the Physical Characteristics of Expansive Clay Soils from Syria

Ammar N. Alnmr R. P. Ray

Publication Name: Geotechnical and Geological Engineering

Publication Date: 2024-06-01

Volume: 42

Issue: 4

Page Range: 2675-2691

Description:

Expansive clayey soils often pose challenges for construction projects due to their low bearing capacity, swelling, and shrinkage properties. While previous research has explored additives to enhance these soils’ properties, the potential of sand remains underexplored. This study investigates the impact of varying sand percentages on expansive clayey soils’ consistency, compaction, and permeability. This study examines how adding different percentages of sand influences the physical properties of expansive clayey soils. Laboratory tests involved systematic testing of texture, compaction, and permeability. Findings reveal a notable improvement in the physical properties of the soil with the addition of sand. Results from the laboratory tests provided data for empirical equations that facilitate the prediction of soil properties based on the sand content. The enhancement in soil properties underscores the potential of sand as an additive for expansive clayey soils. The empirical equations presented here provide practical benefits to geotechnical engineers and practitioners engaged in construction projects involving these soils, offering them valuable insights into the benefits of sand additives to improve physical characteristics. The insights gained from this research hold promising prospects for improving construction practices and addressing the challenges associated with these soils.

Open Access: Yes

DOI: 10.1007/s10706-023-02698-w

Novel Insights in Soil Mechanics: Integrating Experimental Investigation with Machine Learning for Unconfined Compression Parameter Prediction of Expansive Soil

Chuangxin Lyu Haidar Hosamo Hosamo Ammar N. Alnmr Mounzer Omran Alzawi R. P. Ray

Publication Name: Applied Sciences Switzerland

Publication Date: 2024-06-01

Volume: 14

Issue: 11

Page Range: Unknown

Description:

This paper presents a novel application of machine learning models to clarify the intricate behaviors of expansive soils, focusing on the impact of sand content, saturation level, and dry density. Departing from conventional methods, this research utilizes a data-centric approach, employing a suite of sophisticated machine learning models to predict soil properties with remarkable precision. The inclusion of a 30% sand mixture is identified as a critical threshold for optimizing soil strength and stiffness, a finding that underscores the transformative potential of sand amendment in soil engineering. In a significant advancement, the study benchmarks the predictive power of several models including extreme gradient boosting (XGBoost), gradient boosting regression (GBR), random forest regression (RFR), decision tree regression (DTR), support vector regression (SVR), symbolic regression (SR), and artificial neural networks (ANNs and proposed ANN-GMDH). Symbolic regression equations have been developed to predict the elasticity modulus and unconfined compressive strength of the investigated expansive soil. Despite the complex behaviors of expansive soil, the trained models allow for optimally predicting the values of unconfined compressive parameters. As a result, this paper provides for the first time a reliable and simply applicable approach for estimating the unconfined compressive parameters of expansive soils. The proposed ANN-GMDH model emerges as the pre-eminent model, demonstrating exceptional accuracy with the best metrics. These results not only highlight the ANN’s superior performance but also mark this study as a groundbreaking endeavor in the application of machine learning to soil behavior prediction, setting a new benchmark in the field.

Open Access: Yes

DOI: 10.3390/app14114819

Impact of soil composition on maximum depth of wetting in expansive soils

Ammar N. Alnmr

Publication Name: Pollack Periodica

Publication Date: 2024-03-22

Volume: 19

Issue: 1

Page Range: 85-92

Description:

Expansive unsaturated soils present challenges in construction due to their moisture-induced behavior. This study proposes empirical equations to estimate the maximum wetting depth over time. Laboratory experiments and numerical analyses using SEEP/W software investigate wetting depth considering time and sand content in coastal and inland regions. Results reveal the significant influence of sand content on maximum soil moisture depth, emphasizing a recommended content above 30% to mitigate heave. The equations offer practical tools for assessing wetting depth, accounting for temporal and spatial variations. This research highlights the importance of wetting depth in addressing soil-related concerns and provides a foundation for further exploration of related factors.

Open Access: Yes

DOI: 10.1556/606.2023.00870

Experimental Investigation of the Soil-Water Characteristic Curves (SWCC) of Expansive Soil: Effects of Sand Content, Initial Saturation, and Initial Dry Unit Weight

Safwan Abdullah Ammar N. Alnmr Jihad Ibraheem Mounzer Omran Alzawi R. P. Ray

Publication Name: Water Switzerland

Publication Date: 2024-03-01

Volume: 16

Issue: 5

Page Range: Unknown

Description:

Soil-water characteristic curve (SWCC) is an essential parameter in unsaturated soil mechanics, and it plays a significant role in geotechnical engineering to enhance theoretical analysis and numerical calculations. This study investigated the effects of key factors, such as the percentage of sand, initial degree of saturation, and initial dry unit weight, on the SWCC of expansive soil by measuring the matric suction using a pressure apparatus method. The empirical equation of SWCC was obtained using the Van Genuchten and Fredlung Xing models, and the processing of experimental data checks the fitting of the two empirical models. The findings revealed that the Fredlung Xing model fit the relationship between matric suction and volumetric water content of expansive soil better than the Van Genuchten model, indicating that the pressure apparatus approach’s experimental data are correct and acceptable. The study also found that the matric suction increased with decreasing percentage of added sand at the same volumetric moisture content, and the increase in initial dry unit weight increased the matric suction, with the water retention capacity decreasing significantly after adding 20% sand. Moreover, as the initial degree of saturation increased, the volumetric water content decreased, and the characteristic curves became identical when the initial saturation degree reached 90%. Finally, to minimize the water retention capacity of expansive soils, the study recommended adding a percentage of sand not less than 30% to the expansive clay sample.

Open Access: Yes

DOI: 10.3390/w16050627

A Novel Approach to Swell Mitigation: Machine-Learning-Powered Optimal Unit Weight and Stress Prediction in Expansive Soils

Ammar N. Alnmr Mounzer Omran Alzawi R. P. Ray

Publication Name: Applied Sciences Switzerland

Publication Date: 2024-02-01

Volume: 14

Issue: 4

Page Range: Unknown

Description:

Expansive soils pose significant challenges to structural integrity, primarily due to volumetric changes that can lead to detrimental consequences and substantial economic losses. This study delves into the intricate dynamics of expansive soils through loaded swelling pressure experiments conducted under diverse conditions, encompassing variations in the sand content, initial dry unit weight, and initial degree of saturation. The findings underscore the pronounced influence of these factors on soil swelling. To address these challenges, a novel method leveraging machine learning prediction models is introduced, offering an efficient and cost-effective framework to mitigate potential hazards associated with expansive soils. Employing advanced algorithms such as decision tree regression (DTR), random forest regression (RFR), gradient boosting regression (GBR), extreme gradient boosting (XGBoost), support vector regression (SVR), and artificial neural networks (ANN) in the Python software 3.11 environment, this study aims to predict the optimal applied stress and dry unit weight required for soil swelling mitigation. Results reveal that XGBoost and ANN stand out for their precision and superior metrics. While both performed well, ANN demonstrated exceptional consistency across training and testing phases, making it the preferred choice. In the tested dataset, ANN achieved the highest R-squared values (0.9917 and 0.9954), lowest RMSE (7.92 and 0.086), and lowest MAE (5.872 and 0.0488) for predicting optimal applied stress and dry unit weight, respectively.

Open Access: Yes

DOI: 10.3390/app14041411

Numerical Study of the Effect of the Shape and Area of Shallow Foundations on the Bearing Capacity of Sandy Soils

Rashad Alsirawan Ammar N. Alnmr

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2024-01-01

Volume: 21

Issue: 1

Page Range: 103-120

Description:

The settlement and bearing capacity of shallow foundation models with different shapes and areas on cohesionless subsoil under the applied vertical load are presented in this study. Different shapes of foundations with rectangular, square, strip, plus horizontal cross-sectional shapes are numerically studied after the validation on the laboratory model has been conducted and the constitutive soil model that simulates the behaviour of sandy soil has been chosen. The result of the validation showed that the HS model is the most suitable for the simulation of stress-deformation behaviour of sand. The effect of the shape and area are clearly visible and greatly affects the bearing capacity of the soil. The study generally compared Vesic's, Hansen's and German’s bearing capacity equations and showed that Vesic's and Hansen's bearing capacity equations are best suited to the bearing capacity computed from numerical analysis by Plaxis3D. Finally, as a development of Hansen's bearing capacity equation, a new equation of plus shape foundation bearing capacity has been determined.

Open Access: Yes

DOI: 10.12700/APH.21.1.2024.1.7

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

Parametric Investigation of Interaction between Soil-Surface Structure and Twin Tunnel Excavation: A Comprehensive 2D Numerical Study

Hussein Ahmad Ammar N. Alnmr Ashraf Sheble R. P. Ray

Publication Name: Infrastructures

Publication Date: 2023-08-01

Volume: 8

Issue: 8

Page Range: Unknown

Description:

The growing demand for transportation tunnels in densely populated urban areas has led to the widespread adoption of twin tunnel configurations in contemporary infrastructure projects. This research focuses on investigating the complex interaction between soil, structures, and the excavation of twin tunnels. The study employs the tunnel boring machine (TBM) method and utilizes two-dimensional numerical modeling based on the finite element method (FEM). The numerical model is validated by comparing its results with field measurements obtained from a twin tunnel project in Italy, specifically the New Milan Metro Line 5. A comprehensive parametric study is conducted to analyze various parameters that influence soil–structure interaction during tunnel excavation. These parameters include the positioning of the tunnels in relation to each other, the spacing between them, the presence of structures above the tunnels, eccentricity between the structure axis and tunnel axis, and tunnel depth and diameter. Moreover, a comparative analysis is performed between scenarios with and without structures to elucidate the impact of structure presence on the interaction phenomenon. The research findings provide valuable insights into the intricate behavior of twin tunnels and their interaction with the surrounding soil and structures.

Open Access: Yes

DOI: 10.3390/infrastructures8080124

Numerical simulation of replacement method to improve unsaturated expansive soil

Ammar N. Alnmr R. P. Ray

Publication Name: Pollack Periodica

Publication Date: 2023-07-11

Volume: 18

Issue: 2

Page Range: 41-47

Description:

In this paper, a parametric study is done with various removal and replacement materials to study the effectiveness of the removal and replacement method on the wetting depth in the expansive soil and the amount of differential heave caused by climate conditions and common irrigation scenarios for the southern region of Syria. Soil suction changes and associated soil deformations are analyzed using finite element codes, VADOSE/W and SIGMA/W. The paper concludes that the optimum thickness for replacement with high permeability soil should be at least 1 m. In addition, it concludes that replacing soil with a permeability coefficient lower than the permeability coefficient of the site soil contributes to a 56% and 79% reduction in total and differential heave, respectively.

Open Access: Yes

DOI: 10.1556/606.2023.00762

Two-Dimensional Numerical Analysis for TBM Tunneling-Induced Structure Settlement: A Proposed Modeling Method and Parametric Study

Rashad Alsirawan Ammar N. Alnmr Ashraf Sheble

Publication Name: Infrastructures

Publication Date: 2023-05-01

Volume: 8

Issue: 5

Page Range: Unknown

Description:

The construction of tunnels in densely populated urban areas poses a significant challenge in terms of anticipating the settlement that may result from tunnel excavation. This paper presents a new and more realistic modeling method for tunnel excavation using a Tunnel Boring Machine (TBM). This method is compared with other reference modeling methods using a validated model of a subsurface tunnel excavated by a TBM with a slurry shield. A parametric study is conducted to investigate the impact of key parameters, including structure width, foundation depth, eccentricity, load on the structure, overburden depth, and tunnel diameter, on tunnel–soil–structure interaction and the resulting structure settlements. The results reveal that the tunnel diameter, eccentricity, and overburden depth have a significant impact on structure settlements, with values of 22.5%, 17%, and 7.1%, respectively. Finally, the paper proposes an equation for predicting the maximum settlement of a structure, considering the critical parameters. The validity of the equation is evaluated by comparing its results with the outputs from various case studies, including a newly validated model, two real-life case studies, and centrifuge tests. The results indicate a high level of consistency between the calculated and measured settlements.

Open Access: Yes

DOI: 10.3390/infrastructures8050088

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

Dynamic behavior of gravity segmental retaining walls

Rashad Alsirawan Ammar N. Alnmr

Publication Name: Pollack Periodica

Publication Date: 2023-03-07

Volume: 18

Issue: 1

Page Range: 94-99

Description:

This work aims to highlight gravity segmental retaining walls with their varied advantages. The paper investigates the dynamic behavior analysis of segmental retaining walls. The stability analysis is conducted on the basis of a pseudo-static Mononobe-Okabe theory that provides safety factors against sliding and overturning failure. The results demonstrate that the crucial safety factor of internal stability is the safety factor against overturning. Moreover, the positive wall inclination angle contributes to an improvement in the stability of the segmental retaining walls and the effect of the vertical seismic coefficient on the stability can be disregarding. Finally, a new equation is proposed for the elementary design of the segmental retaining walls.

Open Access: Yes

DOI: 10.1556/606.2022.00722

A State-of-the-Art Review and Numerical Study of Reinforced Expansive Soil with Granular Anchor Piles and Helical Piles

Rashad Alsirawan Ammar N. Alnmr R. P. Ray

Publication Name: Sustainability Switzerland

Publication Date: 2023-02-01

Volume: 15

Issue: 3

Page Range: Unknown

Description:

Expansive soils exist in many countries worldwide, and their characteristics make them exceedingly difficult to engineer. Due to its significant swelling and shrinkage characteristics, expansive soil defies many of the stabilization solutions available to engineers. Differential heave or settlement occurs when expansive soil swells or shrinks, causing severe damage to foundations, buildings, roadways, and retaining structures. In such soils, it is necessary to construct a foundation that avoids the adverse effects of settlement. As a result, building the structure’s foundations on expansive soil necessitates special consideration. Helical piles provide resistance to uplift in light structures. However, they may not fully stabilize foundations in expansive soils. A granular anchor pile is another anchor technique that may provide the necessary resistance to uplift in expansive soils using simpler methods. This review and numerical study investigate the fundamental foundation treatments for expansive soils and the behavior of granular anchors and helical piles. Results indicate that granular anchor piles performed better than helical piles for uplift and settlement performance. For heave performance, the granular anchor and helical piles perform nearly identically. Both achieve heave reductions greater than 90% when L/H > 1.5 and D = 0.6 m.

Open Access: Yes

DOI: 10.3390/su15032802

The Significance of Data Integration in Geotechnical Engineering: Mitigating Risks and Enhancing Damage Assessment of Expansive Soils

Ammar N. Alnmr R. P. Ray

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 541-546

Description:

Geotechnical Engineering is a data-driven specialty that models the behavior of soil and rock as engineering materials. Due to their nature, however, much effort is directed toward defining the material properties and extent of various soil and rock on a site (buildings, bridges, dams) or region (transportation infrastructure). The great extent and variability of soil as an engineering material have led to the development of material, field exploration, and laboratory testing databases. Some have become national in scope, while others have expanded along specialist lines (e.g., earthquakes, landslides). This paper presents a typical application that investigates the impact of swelling clays and discusses its integration into the BENIP framework, with an emphasis on its role in advancing sustainability in geotechnical engineering. The study employs artificial neural networks as a modeling tool to predict crucial parameters such as dry density and in-situ confining stress, which directly influence volumetric changes in the soil. By minimizing these changes, potential damage associated with swelling clays, including ground movement, foundation deterioration, and infrastructure instability, can be mitigated. The results of the study exhibit promising outcomes, signifying the potential effectiveness of the proposed neural network models in promoting sustainability in geotechnical engineering.

Open Access: Yes

DOI: 10.3303/CET23107091

A review of the Digital Twin technology for fault detection in buildings

Henrik Kofoed Nielsen Paul Ragnar Svennevig Haidar Hosamo Hosamo Ammar N. Alnmr Kjeld Svidt

Publication Name: Frontiers in Built Environment

Publication Date: 2022-11-09

Volume: 8

Issue: Unknown

Page Range: Unknown

Description:

This study aims to evaluate the utilization of technology known as Digital Twin for fault detection in buildings. The strategy consisted of studying existing applications, difficulties, and possibilities that come with it. The Digital Twin technology is one of the most intriguing newly discovered technologies rapidly evolving; however, some problems still need to be addressed. First, using Digital Twins to detect building faults to prevent future failures and cutting overall costs by improving building maintenance is still ambiguous. Second, how Digital Twin technology may be applied to discover inefficiencies inside the building to optimize energy usage is not well defined. To address these issues, we reviewed 326 documents related to Digital Twin, BIM, and fault detection in civil engineering. Then out of the 326 documents, we reviewed 115 documents related to Digital Twin for fault detection in detail. This study used a qualitative assessment to uncover Digital Twin technology’s full fault detection capabilities. Our research concludes that Digital Twins need more development in areas such as scanner hardware and software, detection and prediction algorithms, modeling, and twinning programs before they will be convincing enough for fault detection and prediction. In addition, more building owners, architects, and engineers need substantial financial incentives to invest in condition monitoring before many of the strategies discussed in the reviewed papers will be used in the construction industry. For future investigation, more research needs to be devoted to exploring how machine learning may be integrated with other Digital Twin components to develop new fault detection methods.

Open Access: Yes

DOI: 10.3389/fbuil.2022.1013196

Material Models to Study the Effect of Fines in Sandy Soils Based on Experimental and Numerical Results

Ammar N. Alnmr

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-11-24

Volume: 14

Issue: 4

Page Range: 651-680

Description:

Choosing and calibrating a robust and accurate soil material model (constitutive model) is the first important step in geotechnical numerical modelling. A less accurate model leads to poor results and more difficulty estimating true behaviour in the field. Subsequent design work is compromised and may lead to dangerous and costly mistakes. In this research, laboratory experimental results were used as a basis to evaluate several soil material models offered in Plaxis2D software. The deciding feature of the soil model was how well it could represent effects of percentage of fine material within sandy soils to simulate its behaviour. Results indicate that the Hardening Soil (HS) model works well when the percentage of fine (soft) materials is less than 10%. Above that level, the Soft Soil model (SS) becomes the most suitable. Finally, some important conclusions about this research and recommendations for future research are highlighted.

Open Access: Yes

DOI: 10.14513/actatechjaur.00625

Review of the effect of sand on the behavior of expansive clayey soils

Ammar N. Alnmr R. P. Ray

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-11-24

Volume: 14

Issue: 4

Page Range: 521-552

Description:

Clayey soils often showed undesirable engineering behavior such as low bearing capacity, swelling and shrinkage characteristics. However, chemical improvement, thermal improvement and improvement by additives like lime, cement and sand offer an efficient technique to overcome the problems resulting from Expansive soils. This paper presents a review of the swelling behavior of sand-clay mixtures as well as the effect of sand on the physical and mechanical characteristics of expansive soils. Results highlight the importance of sand in improving the behavior of expansive soils. Finally, the most important general conclusions about the behavior of expansive soils and suggestions for future researches are highlighted.

Open Access: Yes

DOI: 10.14513/actatechjaur.00611