scholarly journals Effect of Keratin Structures from Chicken Feathers on Expansive Soil Remediation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Elda Montes-Zarazúa ◽  
Arturo Colín-Cruz ◽  
María de la Luz Pérez-Rea ◽  
Miguel de Icaza ◽  
Carlos Velasco-Santos ◽  
...  
Keyword(s):  
Random Distribution ◽  
Expansive Soils ◽  
Complex Structure ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Degree Of Saturation ◽  
One Dimensional ◽  
Chicken Feathers ◽  
Swelling Characteristics ◽  
First Time

Chicken feathers are composed mainly of avian keratin, a fibrillar protein with a complex structure, and important properties such as durability, hydrophobicity, being chemically unreactive, and depending on the specific function can change its morphological and inner structure. This study takes advantage of these features and for the first time the use of keratin from chicken feathers to modify characteristics on expansive soils is reported. Swelling characteristics of remolded expansive soil specimens were studied through varying the percentage of keratin fiber content using 0.25, 0.50, 1.00 and 3.00 wt%. One-dimensional swell-consolidation tests were conducted on oedometric specimens, specific surface area was determined using methylene blue, and degree of saturation was also analyzed. Finally random distribution and interaction between keratin structures and soil were studied by scanning electron microscopy. The results show that randomly distributed fibers are useful in restraining the swelling tendency of expansive soils. The maximum reduction of pressure (43.99%) due to swelling is achieved by reducing the void ratio, which can be reached with the addition of chicken feather keratin structures to the expansive soil. Finally, the mechanism by which discrete and randomly distributed fibers reduce swelling pressure of expansive soil is explained.

scholarly journals An Experimental Study on the Effect of Micro-Metakaolin on the Strength and Swelling Characteristics of Expansive Soils

2022 ◽  
Author(s):  
Mohamed Sakr ◽  
Waseim Azzam ◽  
Mohamed Meguid ◽  
Hebatalla Ghoneim
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Soil Conditions ◽  
Arid Areas ◽  
Continuous Increase ◽  
Swell Index ◽  
The World ◽  
Swelling Characteristics ◽  
The Government

Abstract Expansive soils are found in many parts of the world, especially in arid areas and dry weather regions. Urbanization and development of new cities around the world resulted in construction in areas of challenging subsurface soil conditions. For example, in the Middle East, the Government of Egypt is building several new cities to accommodate the continuous increase in the country’s population. Most of these new cities are located in areas underlain by expansive soils. In this study, a series of laboratory tests were carried out to investigate the effect of introducing micro-metakaolin into the matrix of an expansive soil to improve the swelling potential as a new stabilizing material. Test results showed that micro-metakaolin can considerably decrease the free swell index of the soil by 37% and 54% at micro-metakaolin content of 15% and 25%, respectively. In addition, the shear strength of the soil was found to also increase as a result of the introduction of the micro-metakaolin material. Adding 25% micro-metakaolin content reduced the swelling pressure of the soil by about 33%. The results suggest that the proposed method is efficient in stabilizing and improving the properties of expansive soils found in arid areas. This is important to control excessive swelling and prevent possible damage to the supported structures.

Increasing pull-out capacity of granular pile anchors in expansive soils using base geosynthetics

2000 ◽  
Vol 37 (4) ◽  
pp. 870-881 ◽  
Author(s):  
B R. Phani Kumar ◽  
N Ramachandra Rao
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Ground Movement ◽  
Anchor Plate ◽  
Pull Out ◽  
Swelling Soil ◽  
Granular Pile ◽  
Load Rate ◽  
Uplift Load

Granular pile anchors are innovative and effective in resisting the uplift pressure exerted on the foundation by a swelling expansive soil. In a granular pile anchor, the foundation is anchored at the bottom of the granular pile to an anchor plate with the help of a mild steel rod. This renders the granular pile tension-resistant and enables it to offer resistance to the uplift force exerted on the foundation by the swelling soil. This resistance to uplift or pull-out load depends mainly upon the shear parameters of the pile-soil interface and the lateral swelling pressure of the soil, which confines the pile radially and prevents it from being uplifted. The resistance to uplift can be increased by placing a base geosynthetic above the anchor plate so that it forms an integral part of the granular pile anchor. The increase in resistance is due to the friction mobilized between the geosynthetic and the confining media when the uplift load acts on the pile and the geosynthetic moves along with the pile. Hence it depends on the friction between the geosynthetic and the confining media and the area and stiffness of the geosynthetic. This paper discusses the effects of these parameters on pull-out load, rate of heave, and relative ground movement near the pile surface.Key words: expansive soil, granular pile anchor, base geosynthetic, ground movement, rate of heave, pull-out load.

Review of Oedometer Method for Predicting Heave on the Expansive Soil

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Willis Diana ◽  
◽  
Agus Setyo Muntohar ◽  
Anita Widianti ◽  
◽  
...  
Keyword(s):  
State Of The Art ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Foundation Design ◽  
Swelling Properties ◽  
One Dimensional ◽  
Testing Procedures ◽  
Frequent Use ◽  
The One ◽  
Heave Prediction

In foundation design on an expansive soil, the most critical step is to quantify accurately the magnitude of heave and swelling pressure due to change in moisture content. The one-dimensional oedometer has been widely accepted method to determine the heave and swelling pressure of expansive soil. Its simplicity, suitability, and the availability were the reasons for the frequent use of oedometer swell testing technique, but many procedures were identified to measure the swelling properties. Each testing procedures were not unique and resulted different swelling properties and heave prediction. Then, this paper provides an overview of various existing heave prediction by oedometer methods and evaluate common practices of this methods. The techniques were reviewed systematically and summarized. The study summarized a state-of-the-art heave prediction based on the oedometer methods. Various equations forms to predict heave based on the oedometer method have been presented, but the fundamental principles were the same to propose the equation of heave prediction. The differences in these methods were related to the procedures in which the heave index parameter were determined. The three main procedures of oedometer test, i.e. consolidation swell (CS), constant volume CV, and swell overburden (SO), have been summarized. Most of the heave prediction uses the parameter from CS and CV methods. Several reports have shown that the closest estimates of field heave were predicted based on CV method.

scholarly journals Full Scale Modeling of Footing Supported on Expansive Soil using Concrete Pile Anchor Foundation (CPAF).

2020 ◽  
Vol 8 (6) ◽  
pp. 1859-1864
Keyword(s):  
Expansive Soils ◽  
Limit State ◽  
Expansive Soil ◽  
Site Investigation ◽  
Ultimate Limit State ◽  
Upward Movement ◽  
Scale Modeling ◽  
Concrete Pile ◽  
Swelling Characteristics ◽  
A Site

Buildings constructions over expansive soils are exposed to many problems and cracks. The most damaging issues occur due to differential heave displacements, which cause excessive deformations to the overlying structure up to and beyond its serviceability limit state and, in the worst cases, its ultimate limit state. A site investigation is performed for the study area at Tabuk University, Kingdom of Saudi Arabia. The geotechnical soil properties and swelling characteristics were determined. Visual observations of samples obtained from drilled boreholes at study area revealed reddish brown to grey thinly laminated weathered shale followed by shale formation, the subsurface formation is classified (CH) according to USCS. The research study is aimed at measuring the contact pressure at field and studying the efficiency of concrete pile anchor foundation (CPAF) system in reducing heave of footings constructed on expansive soil. In the field, two full scales reinforced concrete footings with and without concrete anchor piles were constructed on top of the expansive shale. After construction of field prototypes, the test area is wetted for 64 days. Monitoring of the footing movement indicated that the footing upward movement using CPAF system caused a 62% less than the footing constructed directly on expansive shale.

scholarly journals Prediction of final settlements of buildings constructed on expansive soils

2015 ◽  
Vol 4 (3) ◽  
pp. 424
Author(s):  
María-de-la-Luz Pérez-Rea ◽  
Tania Ayala ◽  
Victor Castano
Keyword(s):  
Soil Structure ◽  
Expansive Soils ◽  
Volumetric Strain ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Soil Structure Interaction ◽  
Soil Behavior ◽  
Building Conditions ◽  
Structure Interaction ◽  
Strain Coefficient

Because the action of the swelling pressure, the settlements caused by the transmitted load from the structure on expansive soils, and the settlements calculated by classic theories of soils mechanics are different. This swelling pressure acts in opposite direction to the weight of the building. In this paper, the authors propose the use of a volumetric strain coefficient by settlements exp, in a soil-structure interaction algorithm taking into account the expansive soil behavior in the reduction of the settlement magnitude when a building is placed above soil. It’s necessary to know the initial properties of the expansive unsaturated soil and the load building conditions. A laboratory process is described for determining the aexpcoefficient.

Studies on the determination of swelling properties of soils from suction measurements

2011 ◽  
Vol 48 (3) ◽  
pp. 375-387 ◽  
Author(s):  
B. Hanumantha Rao ◽  
K. Venkataramana ◽  
D. N. Singh
Keyword(s):  
Expansive Soils ◽  
Swelling Pressure ◽  
Soil Suction ◽  
Swelling Potential ◽  
Empirical Relationships ◽  
Swelling Properties ◽  
Swelling Characteristics ◽  
Stability Of Structures ◽  
Made In

Expansive soils exhibit significantly high volumetric deformations and hence, pose a serious threat to stability of structures and foundations. As such, determination of their swelling properties (viz., swelling potential and swelling pressure) becomes essential. Earlier researchers have developed various experimental techniques, and empirical relationships based on the results obtained from these investigations, for determining swelling characteristics of these soils. However, although these techniques help in direct estimation of the swelling properties of soils, the instrumentation is quite cumbersome and time consuming. This limitation can be overcome by measuring soil suction, which would also yield its swelling characteristics, though indirectly, but quite rapidly and easily. To demonstrate the utility and ease of application of this methodology, attempts were made in the present study to establish swelling properties of expansive soils from their suction measurements. Details of the methodology adopted are presented and results have been critically evaluated vis-à-vis those available in the literature.

Model for the simulation of swelling-pressure measurements on expansive soils

1998 ◽  
Vol 35 (1) ◽  
pp. 96-114 ◽  
Author(s):  
Fangsheng Shuai ◽  
D G Fredlund
Keyword(s):  
Pore Water ◽  
Volume Change ◽  
Unsaturated Soil ◽  
Pore Water Pressure ◽  
Expansive Soils ◽  
Water Pressure ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Oedometer Test ◽  
Free Swell

Numerous laboratory swelling tests have been reported for the measurement of swelling pressure and the amount of swell of an expansive soil. These test methods generally involve the use of a conventional one-dimensional oedometer apparatus. Few attempts, however, have been made to formulate a theoretical framework to simulate the testing procedures or to visualize the different stress paths followed when using the various methods. The simulation of the oedometer tests on expansive soils is required to fully understand the prediction of heave. The correct measurement of swelling pressure is required for an accurate prediction of heave. It is further anticipated that some information on unsaturated soils property functions may be approximated from the back-analysis of the data. A theoretical model is proposed to describe the pore-water pressures with time and depth in a specimen as well as the volume changes during various oedometer swell tests. The model is formulated based on equilibrium considerations, constitutive equations for an unsaturated soil, and the continuity requirement for the pore fluid phases. The transient water flow process is coupled with the soil volume change process. The model can be used to describe the volume-change behaviour, pore-water pressure, and vertical total stress development in an unsaturated soil during an oedometer test performed by any one of several test procedures. The model has been put into a finite element formulation using the Galerkin technique. All the parameters required to run the model can be obtained by performing independent, common laboratory tests. The proposed model was used to simulate the results from free-swell, constant-volume, constant water content, and loaded-swell oedometer tests. Computed values of volume change, vertical total stress, and pore-water pressure are in good agreement with measured values.Key words: unsaturated soil, expansive soil, swelling pressure, theoretical simulation, constant-volume oedometer test, free-swell oedometer test, loaded-swell oedometer test.

scholarly journals Factors affecting the swelling pressure for Jerash expansive soil

2021 ◽  
Vol 3 (2) ◽  
pp. 44-51
Author(s):  
Talal Masoud ◽  
Abdulrazzaq Jawish Alkherret
Keyword(s):  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Dry Density ◽  
Initial Water Content ◽  
Content Increase ◽  
Initial Water ◽  
Factors Affecting ◽  
Water Content Increase

  In this study for factors effecting the swelling pressure of jerash expansive soils were investigated in this study, effect of initial dry density and effect of initial water content on the jerash expansive soil were investigated.It show that as the initial dry density decrease from 1.85 gm/cm3  to1.25 gm/cm3 , the swelling pressure also decrease are from 3.1  to 0.25gm/cm2   also it show that as the initial water content increase from 0%to 15% , the swelling pressure of jerash expansive soil decrease from 2.65 gm/cm2  to 1.35 gm/cm2  .  

scholarly journals A Framework for Interpreting Lateral Swelling Pressure in Unsaturated Expansive Soils

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Mingyu Li ◽  
Yanqing Wei ◽  
Yunlong Liu ◽  
Junwei Jin
Keyword(s):  
Expansive Soils ◽  
Soil Mechanics ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Field Studies ◽  
Theoretical Framework ◽  
Water Infiltration ◽  
Civil Infrastructure ◽  
Unsaturated Soil Mechanics ◽  
Unsaturated Expansive Soils

Lateral swelling pressure (LSP) develops when expansive soil volume increment associated with water infiltration is restrained in a confined domain, for example, due to construction of civil infrastructure. In this paper, initially a flowchart is developed to highlight various key factors that influence the LSP mobilization according to lab and field studies collected from previous literature studies. Then extending unsaturated soil mechanics, a theoretical framework is proposed for illustrating the LSP mobilization in the field against retaining structures and pile foundations under different boundary conditions, respectively. An example problem for a basement wall and a pile foundation constructed in a typical expansive soil from Regina, Canada, is presented to illustrate the proposed theoretical framework. The framework and corresponding analysis presented in this paper can facilitate to provide rational designs of geotechnical infrastructures in expansive soils.

Prediction of the variation of swelling pressure and one-dimensional heave of expansive soils with respect to suction using the soil-water retention curve as a tool

2016 ◽  
Vol 53 (8) ◽  
pp. 1213-1234 ◽  
Author(s):  
Hongyu Tu ◽  
Sai K. Vanapalli
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Expansive Soils ◽  
Swelling Pressure ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve ◽  
One Dimensional ◽  
Oedometer Tests

The one-dimensional (1-D) potential heave (or swell strain) of expansive soil is conventionally estimated using the swelling pressure and swelling index values that are determined from different types of oedometer test results. The swelling pressure of expansive soils is typically measured at saturated condition from oedometer tests. The experimental procedures of oedometer tests are cumbersome as well as time-consuming for use in conventional geotechnical engineering practice and are not capable of estimating heave under different stages of unsaturated conditions. To alleviate these limitations, semi-empirical models are proposed to predict the variation of swelling pressure of both compacted and natural expansive soils with respect to soil suction using the soil-water retention curve (SWRC) as a tool. An empirical relationship is also suggested for estimating the swelling index from plasticity index values, alleviating the need for conducting oedometer tests. The predicted swelling pressure and estimated swelling index are then used to estimate the variation of 1-D heave with respect to suction for expansive soils by modifying Fredlund’s 1983 equation. The proposed approach is validated for eight field sites from six countries — namely, Saudi Arabia, Australia, Canada, China, USA, and UK — and on six different compacted expansive soils from USA.

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