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1 – 10 of 19
Article
Publication date: 5 February 2018

Namal Yapage and Samanthika Liyanapathirana

This paper aims to investigate the behaviour of geosynthetic reinforced deep cement mixed (DCM) column-supported embankments constructed over soft soils.

Abstract

Purpose

This paper aims to investigate the behaviour of geosynthetic reinforced deep cement mixed (DCM) column-supported embankments constructed over soft soils.

Design/methodology/approach

Coupled consolidation analyses based on the finite element method are carried out assuming that the soil and DCM columns are fully saturated porous mediums. In the first part of the paper, a case study of an embankment constructed over a very soft soil deposit in Finland is presented. Two- and three-dimensional finite element models for the case study are developed including isolated and attached DCM columns beneath the embankment to capture the arching mechanism between DCM columns. The model simulations were carried out considering the actual staged construction procedure adopted in the field. Finite element predictions show good agreement with field data and confirm that the load transfer is mainly between attached columns beneath the embankment. Next, the significance of geosynthetic reinforcement on the load transfer mechanism is investigated. Finally, the influence of permeability of columns and soft soil on the performance of geosynthetic reinforcement column-supported embankments is studied.

Findings

Results demonstrate that the excess pore pressure dissipation rate is fast in DCM column-improved ground compared to the same case without any columns, although the same permeability is assigned to both DCM columns and surrounding soft soil. When DCM column permeability exceeds soil permeability, excess pore pressure dissipation rate shows a remarkable increase compared to that observed when the DCM column permeability is less than or equal to the permeability of surrounding soft soil. [ ]

Originality/value

This paper investigates the contribution of permeability and geosynthetic layer on the vertical load transfer mechanism of the embankment and modelling issues related to application of the embankment load and the properties of the cement-improved columns.

Details

Journal of Engineering, Design and Technology, vol. 16 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 15 June 2011

Festus Arunaye and Abraham Mwasha

Constrain on availability of waste landfill sites and stinging environmental regulations are the major reasons stimulating interest in the use of Limited Life Materials in…

Abstract

Constrain on availability of waste landfill sites and stinging environmental regulations are the major reasons stimulating interest in the use of Limited Life Materials in construction industry. The concept of limited life geotextiles seeks to emphasize a clear definable working life, where materials are designed so that progressive loss of their capability with time is matched with the improvement in the ground conditions with time. By clearly defining a working life of the geotextile base on the improvements in ground conditions overtime will reduce over-designing and construction. This paper mainly focus on the ability of biodegradable geotextiles to provide reinforcement to embankments constructed on soft ground where the foundation soil is too weak to support the embankment on it. It is well known that any degradable (decay) material has negative exponential function. Consequently nonlinear function which approximates decay phenomenon is engrossed with errors. The existing methods of investigating time dependent behaviors of Basal reinforced embankment on the soft soil are based on discrete functional equations derived from large number of data. This paper provides an update of effective mathematical equation for predicting limited life span of geotextiles derived from the fundamental mathematical and engineering principles which governed biodegradable materials and soil parameters.

Details

World Journal of Engineering, vol. 8 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 24 September 2020

Abhishek Sharma and Ravi Kumar Sharma

The purpose of this paper is to provide a cost-effective foundation technique for the design of foundations of transmission towers, heavily loaded structures, etc.

Abstract

Purpose

The purpose of this paper is to provide a cost-effective foundation technique for the design of foundations of transmission towers, heavily loaded structures, etc.

Design/methodology/approach

Experimental model tests are conducted in a model test tank to find out the effect of length and diameter of geogrid encased granular pile anchors, the relative density of sand and the angle of inclination of the pile from the vertical on uplift behavior of granular pile anchors.

Findings

The uplift capacity of the geogrid encased granular pile anchor increased with increasing length and diameter of granular pile anchor. Further, increasing the relative density of surrounding soil increased uplift capacity of geogrid encased granular pile anchor system. Moreover, increasing the angle of inclination of loading also increased uplift capacity of whole system. Thus, the proposed system can be effectively used in field for further applications.

Originality/value

The paper is helpful for the engineers looking for cost-effective foundation techniques for heavily loaded structures.

Details

Journal of Engineering, Design and Technology , vol. 19 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 26 April 2011

Hossein Moayedi, Bujang B.K. Huat, Thamer Ahmad Mohammad Ali, Afshin Asadi, Fatemeh Moayedi and Mehdi Mokhberi

The purpose of the paper is to present a new method of controlling through susceptible slopes in order to reduce the risk of landslides.

1109

Abstract

Purpose

The purpose of the paper is to present a new method of controlling through susceptible slopes in order to reduce the risk of landslides.

Design/methodology/approach

Geotechnical and geological characteristics were collected and different FEM analyses were carried out in a case study of the Alasht valley in Northern Iran in order to determine susceptibility to landslides and consider appropriate countermeasures. Gravel drain piles have a real feel of reducing the pore water pressure in times of seismic loading, so they are used as a remediation method. The results clearly show their effects and an increase in safety as a result.

Findings

Since the water table situation has a significant effect on stability, the present study focused on an example of using a seepage controlling system and its effect on the safety factor for different slopes in the area of Alasht, Northern Iran. Several FEM analyses were carried out on a landslide susceptible case. The results from FEM analysis of different slopes in the study area show a high susceptibility to landslides for six sites. Installing a gravel drain pile surrounded by a non‐woven geotextile layer leads to an increase in the safety factor against landslides. As a result, after installing gravel drain piles in the upper parts of slopes in order to control run out and ground water rising up in times of heavy rainfall, the safety factor against landslides in both static and seismic loading improved significantly.

Originality/value

The literature regarding controlling seepage in order to reduce the risk of landslides is limited. This paper collects and analyses geotechnical and geological data from the Alasht valley as an example to show the high risk of susceptibility to landslides.

Details

Disaster Prevention and Management: An International Journal, vol. 20 no. 2
Type: Research Article
ISSN: 0965-3562

Keywords

Book part
Publication date: 27 September 2023

Abstract

Details

High Impact Practices in Higher Education: International Perspectives
Type: Book
ISBN: 978-1-80071-197-6

Article
Publication date: 25 January 2021

Zhen Wang, Huanling Wang, Weiya Xu and W.C. Xie

This paper aims to analyze the influence of rotated anisotropy on the stability of slope, the random finite element method is used in this study.

Abstract

Purpose

This paper aims to analyze the influence of rotated anisotropy on the stability of slope, the random finite element method is used in this study.

Design/methodology/approach

The random field is generated by the discrete cosine transform (DCT) method, which can generate random field with different rotated angles conveniently.

Findings

Two idealized slopes are analyzed; it is observed that the rotated angle significantly affects the slope failure risk. The two examples support the conclusion that when the orientation of the layers is nearly perpendicular to the slip surface, the slope is in a relative stable condition. The results of heterogeneous slope with two clay layers demonstrate that the rotated angle of lower layer mainly controls the failure mechanism of the slope, and the rotated angle of upper layer exhibits a significant influence on the probability of slope failure.

Originality/value

The method for rotated anisotropy random field generation based on the DCT has a simple expression with few parameters and is convenient for implementation and practical application. The proposed method and the results obtained are useful for analyzing the stability of the heterogeneous slopes in engineering projects.

Details

Engineering Computations, vol. 38 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 4 April 2023

Soumaya Hadri, Souhila Rehab Bekkouche and Salah Messast

The paper aims to present an experimental and numerical investigation of the load–settlement behavior of soil reinforced by stone column, as well as to evaluate the plane strain…

Abstract

Purpose

The paper aims to present an experimental and numerical investigation of the load–settlement behavior of soil reinforced by stone column, as well as to evaluate the plane strain unit cell model for the analysis of stone columns.

Design/methodology/approach

The numerical analysis was done using both axisymmetric and plane strain models. The elastic perfectly plastic behavior of Mohr–Coulomb was adopted for both soil and column material. The numerical results of this study were validated by the comparison with the in-situ measurements of a full-scale loading test on a stone column. This study also evaluated the effect of different parameters involved in the design of a stone column, including Young’s modulus of the column material, column diameter, spacing between the stone columns and Poisson’s ratio of the column material.

Findings

After the numerical simulation, the results from both axisymmetric and plane strain models are quite comparable. In addition, the numerical results revealed that the stone column with low spacing, a large diameter and a high Young’s modulus indicated better behavior against the settlement.

Originality/value

The axisymmetric unit cell model was used in many numerical studies on the behavior of stone columns. In the present work, a field load test on stone column was simulated using a plane strain unit cell model. This research adds that the plane strain unit cell model can be used to predict the settlement of reinforced soil with stone columns.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 19 July 2011

H.I. Park and Y.T. Kim

Reinforced lightweight soil (RLS) consisting of dredged soil, cement, air‐foam, and waste fishing net is considered to be an eco‐friendly backfilling material because it provides…

1250

Abstract

Purpose

Reinforced lightweight soil (RLS) consisting of dredged soil, cement, air‐foam, and waste fishing net is considered to be an eco‐friendly backfilling material because it provides a means to recycle both dredged soil and waste fishing net. It may be difficult to find an optimum mixing ratio of RLS considering the design criteria and the construction's situation using the limited test results because the unconfined compressive strength is complicatedly influenced by various mixing ratios of admixtures. As a result, in order to expedite the field application of RLS, an appropriate prediction method is needed. The paper aims to address these issues.

Design/methodology/approach

In this study, an artificial neural network (ANN) model that was based on experimental test results performed on various mixing ratios, was developed to predict the unconfined compressive strength of RLS.

Findings

It was found that the unconfined compressive strength of RLS at a given mixing ratio could be reasonably estimated using the developed neural network model. In addition, sensitivity analysis was also conducted to evaluate the effect of mixing conditions on the compressive strength of RLS.

Practical implications

RLS is considered to be environmentally friendly because it provides a means to recycle both dredged soil and waste fishing net. The contractors could use the proposed ANN model as an alternative method to predict the strength of RLS with a specific mixing ratio.

Originality/value

This paper reveals that the developed ANN model can be served as a simple and reliable predictive tool for the strength of RLS without excessive laboratory tests for various admixture contents. An optimum admixture ratio of composed materials to get a designed strength could be easily found by using the proposed ANN model.

Details

Engineering Computations, vol. 28 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 13 October 2021

Ana Junça Silva and Cannanda Lopes

This study aimed to (1) analyze whether the perceived organizational support (POS) was a significant predictor of performance and stress and (2) explore the mediating role of…

Abstract

Purpose

This study aimed to (1) analyze whether the perceived organizational support (POS) was a significant predictor of performance and stress and (2) explore the mediating role of engagement in these relations.

Design/methodology/approach

To test the hypotheses, the authors collected data with 200 working adults in a mandatory quarantine due to COVID-19 pandemic crisis.

Findings

The results showed that the POS contributed to increase engagement, and consequently, job performance. These relations also proved to be significant for stress, because when the POS increased, the work engagement also increased, and as a result decreased occupational stress.

Research limitations/implications

This study relied on a cross-sectional design. Therefore, future research should consider a daily design to replicate this study and analyze daily fluctuations. Overall, the authors can conclude that work engagement is an affective process through which POS decreases stress and increases performance.

Originality/value

This study tests the mediating effect of work engagement on the link between POS, stress and performance, and its theoretical and practical implications of these findings are discussed.

Details

Journal of Economic and Administrative Sciences, vol. 39 no. 4
Type: Research Article
ISSN: 1026-4116

Keywords

Article
Publication date: 9 August 2011

Umit Halis Erdogan and Nilufer Erdem

The purpose of this paper is to propose a theoretical model to predict the mechanical behaviour of needle punched heavy geotextiles in uniaxial tensile test.

Abstract

Purpose

The purpose of this paper is to propose a theoretical model to predict the mechanical behaviour of needle punched heavy geotextiles in uniaxial tensile test.

Design/methodology/approach

The model was constructed using theory of layered composite materials and finite element method. The properties of a reference fabric were used as initial data in theoretical calculations and a commercially available finite element program was chosen to carry out stress analysis. A comparison is made between theoretical calculations and experimental data to evaluate the deformation mechanism of geotextile fabrics in uniaxial tensile test.

Findings

The results indicate that compatible data were predicted in terms of stress values and stress distribution of fabrics. The inconstant lateral contraction of nonwoven fabrics in tensile test is also successfully simulated by the model. However, in the case of elongations, the model could not predict the strains of heavy geotextiles accurately.

Originality/value

The study aims at predicting the mechanical behaviour of needle punched heavy geotextiles by using the structural and mechanical properties of a “reference fabric” instead of constituent fiber properties.

Details

International Journal of Clothing Science and Technology, vol. 23 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

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