scholarly journals The Behavior of Strip Footing Resting on Soil Strengthened with Geogrid

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Duaa Al-Jeznawi ◽  
Adel A. Al-Azzawi
Keyword(s):  
Finite Elements ◽  
Bearing Capacity ◽  
Soil Improvement ◽  
Strip Footing ◽  
Analytical Models ◽  
Number Of Layers ◽  
Settlement Behavior ◽  
Load Carrying ◽  
Low Load ◽  
The World

Abstract The soil in Iraq has a low load carrying or bearing capacity and high deflections or settlement because of the applied loads. The use of strip footing as a foundation to support different kinds of heavy structures has become necessary nowadays through solving such problems by using geogrid. This soil improvement technique is widely used all over the world. In this paper, the bearing capacity and settlements were calculated using finite elements and analytical models for strip footing resting on different kinds of soil. The study parameters are footing rigidity, the number of layers in a geogrid, the dimension of geogrid, and spacing of geogrid layers. According to the findings, the geogrid improved the bearing ability of the footing and reduced settlement. The optimum geogrid dimension was three times the footing width, and three geogrid layers were optimum. The changing in footing rigidity also affects the stress and settlement behavior.

scholarly journals Modelling of fine soils railway embankments behaviour under real cyclic loads

2018 ◽  
Vol 149 ◽  
pp. 02023
Author(s):  
Soufiane GUESSOUS ◽  
Nouzha LAMDOUAR
Keyword(s):  
Finite Elements ◽  
Bearing Capacity ◽  
Mechanical Behaviour ◽  
Cyclic Loads ◽  
Compacted Soils ◽  
Compacted Soil ◽  
Hydraulic Conditions ◽  
The World ◽  
Finite Elements Modelling

Before the development of regulations, standards and guides for infrastructure building, embankments were generally constructed, by reusing and compacting the excavation materials. Therefore, a large part of existing railway embankments, over the world, is composed of fine compacted soils such as clay or marl. However, the current international trend of the railway undertakings and transport contractors is within the intensification of traffic, and the increase of train’s load and speed. Therefore, infrastructure managers are always called upon to evaluate the bearing capacity of existing infrastructures and define the necessary reinforcement solutions. In this perspective, a better awareness and knowledge of the behaviour of fine soils railway embankments is required to define optimal and efficient reinforcement solutions. In that matter, the article will feature the results of finite elements modelling of instrumented railway embankments that were constructed in Morocco in 1920, with marl compacted soil. The model is based on real applied loads and hydraulic conditions monitored for the last three years, which allow to simulate the hydro-mechanical behaviour of the embankment for this period. The article will be also comparing real monitored deformations recorded by the inclinometers equipping the embankments, with the output of the model using different models and adjustments.

scholarly journals Effectiveness of strip footing with geogrid reinforcement for different types of soils in Mosul, Iraq

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243293
Author(s):  
Noor Ibrahim Hasan ◽  
Aizat Mohd Taib ◽  
Nur Shazwani Muhammad ◽  
Muhamad Razuhanafi Mat Yazid ◽  
Azrul A. Mutalib ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soil Improvement ◽  
Reinforced Soil ◽  
Strip Footing ◽  
Shallow Foundation ◽  
Geogrid Reinforcement ◽  
Soil Failure ◽  
Different Types ◽  
Soil Foundation ◽  
Problematic Soil

The main cause of problematic soil failure under a certain load is due to low bearing capacity and excessive settlement. With a growing interest in employing shallow foundation to support heavy structures, it is important to study the soil improvement techniques. The technique of using geosynthetic reinforcement is commonly applied over the last few decades. This paper aims to determine the effect of using geogrid Tensar BX1500 on the bearing capacity and settlement of strip footing for different types of soils, namely Al-Hamedat, Ba’shiqah, and Al-Rashidia in Mosul, Iraq. The analysis of reinforced and unreinforced soil foundations was conducted numerically and analytically. A series of conditions were tested by varying the number (N) and the width (b) of the geogrid layers. The results showed that the geogrid could improve the footing’s bearing capacity and reduce settlement. The soil of the Al-Rashidia site was sandy and indicated better improvement than the other two sites’ soils (clayey soils). The optimum geogrid width (b) was five times the footing width (B), while no optimum geogrid number (N) was obtained. Finally, the numerical results of the ultimate bearing capacity were compared with the analytical results, and the comparison showed good agreement between both the analyses and the optimum range published in the literature. The significant findings reveal that the geogrid reinforcement may induce improvement to the soil foundation, however, not directly subject to the width and number of the geogrid alone. The varying soil properties and footing size also contribute to both BCR and SRR values supported by the improvement factor calculations. Hence, the output complemented the benefit of applying reinforced soil foundations effectively.

scholarly journals Settlement Prediction of a Group of Lightweight Aggregate (LECA) Columns Using Finite Element Modelling

2018 ◽  
Vol 7 (4.35) ◽  
pp. 59
Author(s):  
Azhani Zukri ◽  
Ramli Nazir ◽  
Ng Kok Shien
Keyword(s):  
Finite Element ◽  
Soft Soil ◽  
Soft Clay ◽  
Lightweight Aggregate ◽  
Soil Improvement ◽  
Stone Columns ◽  
Soft Clays ◽  
Settlement Behavior ◽  
Load Carrying ◽  
Settlement Ratio

The method of reinforcing the soft clays with stone columns is the most commonly adopted technique to enhance its load carrying capacity and to reduce settlements. Their performance with respect to bearing capacity is well researched, but the understanding of settlement characteristics still requires extensive investigations. Moreover, no studies have been made to explore the effectiveness of stone columns using Lightweight Expanded Clay Aggregate (LECA) as filler material replacing normal stone/aggregates in order to improve settlement behavior of soft clay. LECA is known as a common lightweight material that have been applied successfully in civil engineering works where weight is an issue because the materials can help to reduce dead loads and lateral forces by more than half in installations over structures and those with soft soils. The purpose of this work is to assess the suitability of reinforcing technique by LECA columns to improve the settlement through finite element. The analysis of performance of LECA column in soft soil improvement was conducted through finite elements methods by using Plaxis 3D commercial software. Based on the results the settlement ratio was reduced as the column length increased until unity at end bearing condition where β=1.0. It is also observed that bulging was reduced with closer spacing between LECA columns.

scholarly journals Sustainable Concrete Application in the Manufacture of University Urban Furniture

2019 ◽  
Vol 303 ◽  
pp. 05001
Author(s):  
Mónica Bedoya ◽  
Federico Rivera ◽  
María Rico ◽  
David Vélez ◽  
Andrés Urrego ◽  
...  
Keyword(s):  
Finite Elements ◽  
Mechanical Characteristics ◽  
Coal Ash ◽  
Sustainable Concrete ◽  
Waste Production ◽  
Construction And Demolition Wastes ◽  
The World ◽  
Sustainable Materials ◽  
The University ◽  
Community Diagnosis

It is clear that construction and demolition wastes (CDW) are constantly increasing throughout the world and these wastes can be used effectively to minimize the consumption of natural resources in the manufacture of more sustainable concrete. The CDW occupy an important segment of world waste production and its generation reached approximately 3 billion tons in 2012 in 40 countries [1]. Although this topic has been studied in the world, it is still valid for the reuse of waste that is constantly increasing, and although in many countries there are already examples of its use this type of concrete in Colombia and in the Medellìn city lacks applications. This project proposes the application of a sustainable concrete made with CDW and coal ash in the Medellín city for its implementation in the construction of urban furniture. A university community diagnosis of the needs in terms of furnishing was made. With the design reached, a modular chair was proposed to enable spaces within the university. The mechanical characteristics of the concrete and the design of the chair are evaluated and a simulation is done through finite elements to evaluate the viability of the proposed concrete, finding that with these properties is possible to manufacture durable and sustainable furniture that serves as an example for the application of sustainable materials

scholarly journals Study on the ultimate bearing capacity of a strip footing influenced by an irregular underlying cavity in karst areas

2021 ◽  
Author(s):  
Lianheng Zhao ◽  
Shan Huang ◽  
Zhonglin Zeng ◽  
Rui Zhang ◽  
Gaopeng Tang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Strip Footing ◽  
Karst Areas

scholarly journals Evaluation of Bearing Capacity of Strip Footing Using Random Layers Concept

2015 ◽  
Vol 37 (3) ◽  
pp. 31-39 ◽  
Author(s):  
Marek Kawa ◽  
Dariusz Łydżba
Keyword(s):  
Monte Carlo ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Design Theory ◽  
Cohesive Soil ◽  
Probability Of Failure ◽  
Mean Value ◽  
Strip Footing ◽  
Random Field Theory ◽  
The Mean

Abstract The paper deals with evaluation of bearing capacity of strip foundation on random purely cohesive soil. The approach proposed combines random field theory in the form of random layers with classical limit analysis and Monte Carlo simulation. For given realization of random the bearing capacity of strip footing is evaluated by employing the kinematic approach of yield design theory. The results in the form of histograms for both bearing capacity of footing as well as optimal depth of failure mechanism are obtained for different thickness of random layers. For zero and infinite thickness of random layer the values of depth of failure mechanism as well as bearing capacity assessment are derived in a closed form. Finally based on a sequence of Monte Carlo simulations the bearing capacity of strip footing corresponding to a certain probability of failure is estimated. While the mean value of the foundation bearing capacity increases with the thickness of the random layers, the ultimate load corresponding to a certain probability of failure appears to be a decreasing function of random layers thickness.

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