scholarly journals Expansive Clay Cracking Behavior through Digital Image Correlation

2020 ◽  
Vol 195 ◽  
pp. 03006
Author(s):  
Arthur Gomes Dantas de Araujo ◽  
Nayara Torres Belfort ◽  
Felipe Araujo Silva Barbosa ◽  
Thalita Cristiana Rodrigues Silva ◽  
Silvio Romero de Melo Ferreira ◽  
...  
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Soil Surface ◽  
Image Correlation ◽  
Northeastern Brazil ◽  
Silty Clay ◽  
Expansive Clay ◽  
Drying Process ◽  
Cracking Behavior ◽  
Engineering Projects

Expansive soils may present cracks arising from the drying process and their evolution can cause irreparable damages to engineering projects. Investigating this phenomenon is vital to understanding its geomechanics. The objective of this article is to present numerical modelling of the formation and propagation of cracks in expansive soil. A desiccation experiment was therefore carried out using an expansive silty clay from Paulista, in northeastern Brazil. The drying process was monitored by measuring the temperature and relative humidity of the air, as well as by capturing images with a camera. The digital images were correlated using the Ncorr numerical tool in MATLAB. As a result, this study made it possible to conclude that the soil cracking dynamics presented a non-orthogonal pattern during the dryness test, while the image treatment made it possible to observe the tendency of cracks to appear and propagate on the soil surface, allowing for the detection of crack growth and propagation trends.

scholarly journals Diagnosis and proposal of erosion control downstream of the Park Alfredo Werner Nyffeler, in Maringá - Paraná

2019 ◽  
Vol 23 ◽  
pp. 4
Author(s):  
Fernanda Assunção Valim ◽  
Monigleicia Alcalde Oriol ◽  
Cipriano José de Azevedo Freire ◽  
Cássia Rocha Pompeu ◽  
Cristhiane Michiko Passos Okawa
Keyword(s):  
Soil Compaction ◽  
Structural Damage ◽  
Efficient Solution ◽  
Retaining Wall ◽  
Local Population ◽  
Expansive Soil ◽  
Soil Surface ◽  
Urban Drainage ◽  
Silty Clay ◽  
Data Survey

The surface runoff role in the urban erosion in Northwest Paraná cities was strengthened by many factors, such as the establishment of the cities often in disaggregated soil areas, vegetation cover removal, soil surface impermeabilization caused by construction and poorly executed embankment areas. In Maringá, Paraná, in a bottom valley located near the park Alfredo Werner Nyffeler, there is an accelerated erosive process, damaging half of the urban drainage pipes, which are located around one meter far from the sidewalk. In that way, it poses a risk to the local population and may lead to a collapse of the drainage structure. Within this context, this work aims to diagnose and identify the possible aspects that caused these issues and to design a gabion wall to stem the significative erosive process occurring in the area. Thus, on-site data survey and laboratory analysis were carried out in order to characterize the soil and, by means of the software GawacWin, a gabion retaining wall in order to use it as a prompt, needed retaining measure was designed. The obtained results showed a lack of awareness by the local population in regard to the solid waste deposition, which accumulates downstream of the park. In addition, the drainage pipes could not cope with the peak flows, causing structural damage, leaks and uncovering the junction box. A silty clay embankment was found in the area, which is an expansive soil, contaminated with rubble and the soil compaction was not properly executed. It was used to level the area for the pipeline passage, contributing to the erosion. A gabion wall, with 6m high and 3m base, showed to be an efficient solution with regard to terrain loads. Furthermore, the price, simple construction and the easy merging with the environment are advantages for the gabion wall, when compared to other structural measures.

scholarly journals Stabilization of Expansive Soil with Polyvinyl Alcohol and Potassium Carbonate

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Fuhai Zhang ◽  
Lei Zhang ◽  
Wangxi Hong
Keyword(s):  
Polyvinyl Alcohol ◽  
Volume Change ◽  
Expansive Soils ◽  
Soil Column ◽  
Ground Surface ◽  
Expansive Soil ◽  
Thick Layer ◽  
Soil Surface ◽  
Compression Tests ◽  
Dense Microstructure

Expansive soils have great volume change potentials with water content changes, which is problematic to facilities. Great efforts have been spent on finding proper methods to stabilize expansive soils, but these stabilizers all had limitations. The Polyvinyl alcohol (PVA) and K2CO3 combination was proposed in this paper. Free swell tests, oedometric tests, unconfined compression tests, and direct shear tests were performed to investigate the effectiveness of the PVA and K2CO3 combination to control the volume change and increase the soil strength. Microstructures of the natural expansive soil and the stabilized soil were also studied with SEM photos. SEM photos showed a homogenous and dense microstructure after stabilization. In addition, a laboratory soil column model was built to study the ability of this stabilizer combination to stabilize expansive soils by directly spraying the solution on the ground surface. All these test results show that the combination of PVA and K2CO3 is able to effectively stabilize the natural expansive soil and increase the shear strength. It is possible to directly spray the stabilizer solution on the soil surface to form a relatively thick layer of the stabilized expansive soil.

Analysis of a New Expansive Soils Stabilization Method Made from Eco-Cement and Fiber Reinforcement

2013 ◽  
Vol 649 ◽  
pp. 217-222
Author(s):  
Mircea Aniculaesi ◽  
Anghel Stanciu ◽  
Irina Lungu
Keyword(s):  
Portland Cement ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Fiber Reinforcement ◽  
Synthetic Fiber ◽  
Expansive Clay ◽  
Swelling Potential ◽  
Stabilization Method ◽  
Swell Potential ◽  
Main Factor

The main factor that governs the shrink-swell behavior of expansive soils is the change in water content and the amount and type of clay size in the soil. In this paper, the research made are focused in reducing the swell potential of the studied clay by improvement in two ways: first by stabilization with a combination of eco-cement and Portland cement (1:1 ratio), and second by synthetic fiber reinforcement. A series of laboratory tests were performed on synthetic fiber reinforced expansive soil to determine the potential for using synthetic fiber reinforcement to reduce swell potential of soils. Specimens tested were prepared at two different synthetic fiber dosages 0.2% and 0.4%. The treatment of expansive clay with 5% eco-cement and 5% Portland cement revealed a better improvement of the swelling potential. The synthetic fiber reinforcement of the expansive soil doesn’t lead to a significant improvement of the soil.

scholarly journals Effect of Iron Chloride on the Strength Behaviour of the Expansive Clay

2018 ◽  
Vol 9 (1) ◽  
pp. 6730-6733
Keyword(s):  
Calcium Chloride ◽  
Civil Engineering ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Iron Chloride ◽  
Black Cotton Soil ◽  
Expansive Clay ◽  
Expansive Clays ◽  
Shrinkage And Swelling ◽  
Strong Electrolytes

From the fast few decades, several techniques were introduced inorder to modify the behaviour of expansive clays. The use of strong electrolytes like calcium chloride (CaCl2 ), aluminum trichloride (AlCl3 ) and iron chloride (FeCl3 ) were extensively used in various civil engineering applications. Expansive soils possesses alternate shrinkage and swelling with the removal and addition of water from it. Iron chloride was effectively used to alter the swelling and shrinkage and also improve the engineering behaviour of expansive clays. Therefore, in the current work an effort is made for study the influence of iron chloride (FeCl3 ) on the strength behaviour of the expansive soil. The outcomes from the laboratory investigation proved that the usage of iron chloride (FeCl3 ) produce reduction in swelling and improvement in the strength. It was found that 1% FeCl3 be the optimum for both the UCS and CBR. Hence, from the investigation it was showed that iron chloride is a valuable stabilizer to enhance the properties of black cotton soil and to create it apt for various applications of Civil Engineering.

scholarly journals Pengaruh Kadar Air Awal Dan Surcharge Pressure Pada Uji Karakteristik Pengembangan Tanah Ekspansif

2017 ◽  
Vol 23 (2) ◽  
pp. 124
Author(s):  
Wilis Diana ◽  
Edi Hartono ◽  
Anita Widianti
Keyword(s):  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Dry Density ◽  
Initial Water Content ◽  
Expansive Clay ◽  
Initial Water ◽  
Swelling Properties ◽  
Swell Percent ◽  
Swell Pressure

Expansive soils experience volumetric changes due to water content changes. These volumetric changes cause swell and shrink movement in soils, which in turn will inflict severe damage to structures built above them. A Proper understanding of how the expansive soil behaves during the wetting/drying process is essential for assessing the mitigation action of expansive soil hazard and design suitable foundation. The structures that build above expansive soil bed are susceptible to heave and to withstand swell pressure, thus the swell pressure must be considered in the design. This study focuses on swelling properties of two expansive clay from Ngawi, East Java and Wates, Yogyakarta. Laboratory test on disturbed samples is used to identified and to measured swelling properties. A series of swelling test was performed under constant soil dry density. The influence of initial water content and surcharge pressure on swelling properties (i.e swell percent and swell pressure) of compacted samples were investigated. The swelling properties test used ASTM standard 4546-03 method B. It was found that the lower initial water content the higher the swell percent, but the swell pressure seems not to be affected by initial water content. At the same initial water content, swell percent decrease with the increase of surcharge pressure, but swell pressure remains unchanged.

scholarly journals Experimental Study on Building Demolished Waste Stabilized Expansive Soil with Potassium Chloride

2018 ◽  
Vol 7 (3.31) ◽  
pp. 214 ◽  
Author(s):  
K M. Ganesh ◽  
A S.S.Vara Prasad ◽  
M Jagapathi Raju
Keyword(s):  
Experimental Study ◽  
Potassium Chloride ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Structural Elements ◽  
Architectural Features ◽  
Moisture Variation ◽  
Loaded Structure ◽  
Engineering Projects

All the civil engineering  projects such as highways, water reservoirs, railways, buildings etc. requires large quantity of earth material. The mankind was wondering about the instability of earth materials especially expansive soil for centuries. Large areas are being covered with highly plastic and expansive soil quite often which is not suitable for such purpose. They can be hard when dry and they can be soft in moist conditions. Soils subjected to volumetric changes with seasonal moisture variation always create problem for lightly loaded structure by consolidating under load. It results in excessive settlement of superstructures usually and differential movements causing damage to foundation systems, structural elements and architectural features. Promising results were obtained by various researchers for the application of such expansive soil after stabilization with additives such as sand, silt, lime, fly ash, etc. A relatively new solid waste, Building Demolished Waste (BDW), can be used for stabilization of expansive soils for various uses in combination with potassium chloride. This study was planned to access the role of potassium chloride inclusions in improving the weak expansive soil besides stabilizing it with Building Demolished Waste in different proportions.  

scholarly journals Model Test Study on Deformation Characteristics of a Fissured Expansive Soil Slope Subjected to Loading and Irrigation

2021 ◽  
Vol 11 (22) ◽  
pp. 10891
Author(s):  
Zhiqing Li ◽  
Youxing Kong ◽  
Le Fu ◽  
Yingxin Zhou ◽  
Zhengfu Qian ◽  
...  
Keyword(s):  
Expansive Soils ◽  
Compressive Strain ◽  
Expansive Soil ◽  
Image Correlation ◽  
Water Infiltration ◽  
Mutual Transformation ◽  
Soil Slope ◽  
Strain Data ◽  
The Impact ◽  
The Relationship

Expansive soils are characterized by repeated swelling and shrinkage. They cause great damage to engineering projects because of their expansiveness, over-consolidation and propensity to crack. However, the impact of cracks on the stability of an expansive soil slope during loading and irrigation is not yet fully understood. This study aimed to investigate the relationship between slope state and crack development in fissured expansive soils. A series of physical model tests with different types of cracks were conducted, in which the fissured expansive soil slopes were subjected to different loadings (1.6, 3.2, 4.8, 6.4, 16 MPa), and irrigated at a flow rate of 25 mL/min. The VIC-2d software, which utilizes the digital image correlation principle, was used to quantitatively obtain the horizontal and vertical strain data of the slope model. The closure and opening of cracks, and the slope state after loading and irrigation were monitored by strain data analysis using VIC-2d software. The results indicate that the excessive overlying stress revives the existing cracks and produces sliding along the crack interface. The sliding surface of the fissured expansive soil slope became shallower due to the water infiltration. It was demonstrated that the middle and foot of the fissured expansive soil slope were the key positions for reinforcement from the perspective of the mutual transformation of tensile strain and compressive strain on the surface of the slope. It is of great importance to study the relationship between the crack strain state and deformation trend of a slope subjected to loading and infiltration to understand the progressive surface- or shallow-layer sliding mechanisms, and reinforce key areas of the slopes in areas containing moderately or strongly expansive soils with abundant cracks.

Foundation Failures Mitigation under Expansive Clay by Using Granular Pile Anchor System

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
Ehab Hamad Sfoog ◽  
◽  
Alvin John Lim Meng Siang ◽  
Nahla Naji ◽  
Sim Sy Yi ◽  
...  
Keyword(s):  
New Technologies ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Cost Effective ◽  
Scale Model ◽  
Expansive Clay ◽  
Uplift Capacity ◽  
Anchor System ◽  
Granular Pile ◽  
Stable Zone

Expansive soils are found in typical areas in the world especially in arid and semi-arid regions. The problems associated with this type of soil drive geotechnical engineers to invent new technologies as remediation’s such as physical and chemical treatments. Innovative foundation techniques were also suggested for remedying the swell-shrink problems of the expansive soil. The granular pile anchor (GPA) is relatively a more favorable technique indebted to its cost-effective, easy and fast to assemble and most importantly was found to be more efficient in remedying the expansive soil. Despite the extensive studies on the expansive soil remedies, yet the granular pile anchor system requires more comprehensive and in-depth investigations. This study is aimed at developing a model with granular piles of various length and diameter extended to the stable zone to investigate the heave and uplift pressure in the expansive soil. For this purpose, experimental and numerical analysis were conducted in a small and in a full scale model respectively. A significant improvement was attained in heave reduction and an increment of uplift capacity. The findings also show that heave decreased significantly when the length and diameter of the GPA increases while the uplift capacity increased. However, it was noted that the extension of length to the stable zone resulted in insignificant changes. Therefore, it can be concluded that the maximum length of 6 m is the ideal length for GPA with different diameters according to foundations design requirement for this particular type of soil.

scholarly journals The Use of Geogrids in Mitigating Pavement Defects on Roads Built over Expansive Soils

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Richard Shumbusho ◽  
Gurmel S. Ghataora ◽  
Michael P.N. Burrow ◽  
Digne R. Rwabuhungu
Keyword(s):  
Seasonal Changes ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Real Field ◽  
Experimental Program ◽  
Swelling Potential ◽  
Swelling Behaviour ◽  
Wetting And Drying ◽  
Potential Benefits

This study was conducted to investigate the potential benefits of using geogrids in mitigating pavement defects notably roughness and longitudinal cracking on pavements built over expansive soils. The seasonal changes of expansive soils (periodic wetting and drying) cause detrimental effects on the overlying road pavements. Such detrimental behavior of expansive soils was simulated in a controlled laboratory environment through allowing cyclic wetting and drying of an expansive soil underlying a pavement section. The shrink/swell effects of the expansive soil subgrade were examined through monitoring its change in moisture, and measuring deformation of overlying pavement section. The experimental study suggested that a geogrid layer in a reinforced pavement section can reduce surface differential shrinking and swelling deformation resulting from underlying expansive soils by a factor of 2 and 3 respectively in comparison to unreinforced section. Given that an oedometer test which is typically used to predict swelling potential of expansive soils is known to overpredict in-situ soil swell, experimental program also investigated quantitatively the extent to which the oedometer can overestimate swelling behaviour of the real-field scenarios. It was found that oedometer percent swell can overpredict in-situ swelling behaviour of the expansive soil by a factor ranging between 2 and 10 depending upon the period over which the in-situ expansive soil has been in contact with water.

scholarly journals STABILISASI TANAH EKSPANSIF MENGGUNAKAN KAPUR DAN SPENT CATALYST UNTUK TANAH DASAR PERKERASAN

2019 ◽  
Vol 19 (1) ◽  
pp. 21-30
Author(s):  
Arifudin Nur ◽  
Suryo Hapsoro Tri Utomo ◽  
M. Zudhy Irawan
Keyword(s):  
Soil Stabilization ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Petroleum Processing ◽  
Spent Catalyst ◽  
Maximum Increase ◽  
Lime Content ◽  
Road Pavement ◽  
Pozzolanic Material ◽  
Spent Catalysts

Abstract Expansive soils have high swelling and shrinkage potentials, which may cause damage to road structures. Therefore, stabilization is required. One method of stabilization is to use lime and spent catalysts with the aim of increasing carrying capacity and reducing swelling. Spent catalyst is a petroleum processing waste and classified as pozzolanic material. The addition of lime and spent catalysts can increase the CBR value and reduce swelling of soils. The results of this study indicate that the maximum increase in soaked CBR and unsoaked CBR values occurred in soil mixtures with optimum lime content and 12% spent catalyst with 7 days of curing. While the soil mixture with optimum lime content and 12% spent catalyst, with 7 days of curing, is the best mixture that produces soaked CBR value of 49.67%, swelling of 0.15%, and plasticity index value of 11.97%, so the soil meets the requirements to be used as pavement subgrade. Keywords: expansive soil, stabilization, road structure, subgrade, road pavement  Abstrak Tanah ekspansif memiliki potensi pengembangan dan penyusutan yang tinggi, sehingga dapat menyebabkan kerusakan struktur jalan. Oleh sebab itu, perlu dilakukan stabilisasi. Salah satu metode stabilisasi adalah menggunakan kapur dan spent catalyst dengan tujuan meningkatkan kapasitas dukung dan menurunkan swelling. Spent catalyst merupakan limbah pengolahan minyak bumi dan termasuk bahan pozzolan. Penam-bahan kapur dan spent catalyst mampu meningkatkan nilai CBR dan mereduksi swelling. Hasil studi ini menunjukkan bahwa peningkatan maksimum nilai CBR soaked maupun CBR unsoaked terjadi pada campuran tanah dengan kadar kapur optimum dan 12% spent catalyst dengan peraman 7 hari. Sedangkan campuran tanah dengan kadar kapur optimum dan 12% spent catalyst, dengan peraman 7 hari, merupakan campuran terbaik yang menghasilkan nilai CBR soaked sebesar 49,67%, swelling sebesar 0,15%, dan nilai indeks plastisitas sebesar 11,97%, sehingga tanah memenuhi syarat untuk digunakan sebagai tanah dasar perkerasan jalan. Kata-kata kunci: tanah ekspansif, stabilisasi, struktur jalan, tanah dasar, perkerasan jalan

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