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.

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 Microbial-Facilitated Calcium Carbonate Precipitation as a Shallow Stabilization Alternative for Expansive Soil Treatment

Geotechnics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 558-572
Author(s):  
Bhaskar C. S. Chittoori ◽  
Tasria Rahman ◽  
Malcolm Burbank
Keyword(s):  
Calcium Carbonate ◽  
Treatment Effectiveness ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Past Research ◽  
Carbonate Precipitation ◽  
Compression Tests ◽  
Calcium Carbonate Precipitation ◽  
Swell Index ◽  
Long Time

Expansive soils generally recognized as swell-shrink soils have been a problem for civil infrastructure for a long time. Engineers are in search of sustainable stabilization alternatives to counter these problematic soils. Microbial-induced calcium carbonate precipitation (MICP) is a promising biocementation process that can improve the properties of expansive soil through calcium carbonate precipitation. Past research has shown promise for the use of MICP in mitigating swelling distress from expansive soils. In this research, MICP via biostimulation was attempted by mixing enrichment and cementation solutions with soils in an effort to develop a new alternative to shallow chemical stabilization. Three soils with varying clay contents (30%, 40%, and 70%) and plasticity characteristics were selected, and soils were treated by mixing with enrichment solutions followed by cementation solutions. Five different mellowing periods, three different curing periods, and two types of cementation solutions were studied to optimize the method. Treatment effectiveness was evaluated using unconfined compression tests, calcium carbonate tests, and free swell index tests. Results showed that an increase in the mellowing period beyond two days was not beneficial for any of the three soils tested in this research. It was determined that the best improvement was observed at two days of mellowing and seven days of curing.

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.

scholarly journals Using Fine Silica Sand and Granite Powder Waste to Control Free Swelling Behavior of High Expansive Soil

2020 ◽  
Vol 15 (1) ◽  
pp. 53
Author(s):  
Manal O. Suliman ◽  
Abdulrazzaq Jawish Alkherret
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Critical Issue ◽  
Soil Samples ◽  
Silica Sand ◽  
Swell Index ◽  
Subgrade Soil ◽  
Free Swell ◽  
Granite Powder

Many researchers have been interested in studying the effect of adding local natural materials or construction waste on the properties of poor subgrade soil. However, changes in size and strength of expansive soils can cause extensive damage to the geotechnical infrastructure. This damage is often repeatable and latent in the long term, and is a critical issue in highway subgrade engineering. This paper examines the effect of adding both Fine Silica Sand (FSS) and Granite Cutting Powder Waste (GPW) materials on the welling characteristics of expansive soils. Atterberg limits, free swell index, and rate of swell of the mixtures were used as a key to assess properties of a group of expansive soil samples after adding different percentages of the mentioned materials. The rates of additions were 10%, 20%, 30%, 40%, 50%, 60 and 70% of the weight of the soil samples. The test results showed that FSS and GPW significantly affect the expansive soil properties. However, adding 70% of both FSS and GPW reduced the swelling index from 58.3% to 6.6% and from 58.3% to 11% after 7 days of curing, respectively. This study suggests that the Fine Silica Sand and Granite Powder Waste can be used as stabilizers for expansive highly plastic soils.

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 Effect of Polymeric Resins on Geotechnical Properties of Black Cotton Soil

2020 ◽  
Vol 8 (5) ◽  
pp. 1781-1785
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Geotechnical Properties ◽  
Black Cotton Soil ◽  
Soil Conditions ◽  
Chemical Stabilization ◽  
Stabilization Method ◽  
Mechanical Stabilization ◽  
Polymeric Resins ◽  
Moisture Barriers

Stabilization of black cotton soil is a challenging task for geotechnical engineers since such soil is highly vulnerable to expansive characteristics when the moisture content is increased. Due to its expansive nature, it is also called as swelling or expansive soils. Among the clay minerals, Montmorillonite is mainly responsible for such expansive characteristics. Bore log profile has a cluster of soil specimens including black cotton soil also which is unavoidable. Soil engineers have a serious concern about such expansive soil since it is treacherous for foundation of buildings. To overcome such deficiencies it becomes essential to stabilize the soil conditions. The commonly employed methods to decrease the expansive behaviour are: Chemical stabilization, Mechanical stabilization and installation of moisture barriers. In this paper, chemical stabilization method is adopted. Soil stabilizers, namely, sodium silicate, epoxy resin and polyvinyl alcohol are chosen and are mixed with black cotton soil in varying proportions of 5%, 10% and 15% to study the changes in geotechnical properties. From the results it is evident that polymer treated soils reduce plasticity characteristics and shows better results in geotechnical properties.

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.

scholarly journals Field-Obtained Soil-Water Characteristic Curves of KPK Expansive Soil and Their Prediction Correlations

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Bakht Zamin ◽  
Hassan Nasir ◽  
Khalid Mehmood ◽  
Qaiser Iqbal
Keyword(s):  
Moisture Content ◽  
Soil Water ◽  
Expansive Soils ◽  
Characteristic Curve ◽  
Ground Surface ◽  
Expansive Soil ◽  
Absorption Capacity ◽  
Water Retention Curve ◽  
Swell Index ◽  
Testing Field

Expansive clays are found worldwide in arid and semiarid regions. Such soils are considered a natural hazard for civil engineering infrastructures especially when they are lightly loaded. Expansive soils are often unsaturated due to the high absorption capacity of moisture. The damaging effect of expansive soils is intimately related to the distinctive soil-water characteristic in the surficial soil layers subjected to wetting-drying cycles. The soil-water characteristic curve (SWCC) also known as the water-retention curve shows the fluctuation of suction with the moisture content. It is one of the key parameters that have been developed and used by soil engineers for studying the properties of partially saturated soils. Currently, the SWCCs produced by most of the researchers are grounded on lab testing which is quite different from the field-obtained curves. In the current study, the SWCCs for Karak expansive soil have been obtained from in situ testing (field). For this purpose, three sites were selected at Amberi Village (Karak) for instrumentation. An open trench of six-foot depth was excavated in each site and instrumented. Electrical resistivity sensors (G-blocks) and tensiometers were used for matric suction measurements. The gravimetric moisture content was measured with the help of moisture sensors calibrated with a speedy moisture meter. To check the fluctuation of moisture and suction, these instruments were installed at three different depths, that is, 0–2, 2–4, and 4–6 feet. Based on results, the maximum suction of 705.79 kPa was observed in the site “A” in 0–2-foot depth (near the ground surface) with a moisture content of 15 percent. The variations in suction and moisture content follow the almost same trend at low suction; however, the trend was slightly different at the moderate suction range. The measured suction showed a strong correlation with the free swell index (FSI) and moisture content. It was found that the upper layers of expansive soil have high suction than lower layers due to more exposure to the environmental agencies and low density.

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.

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