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2024 | Book

Proceedings of the Indian Geotechnical Conference 2022 Volume 4

Geotechnics: Learning, Evaluation, Analysis and Practice (GEOLEAP)

Editors: Babu T. Jose, Dipak Kumar Sahoo, Anand J. Puppala, C. N. V. Satyanarayana Reddy, Benny Mathews Abraham, Ravikiran Vaidya

Publisher: Springer Nature Singapore

Book Series : Lecture Notes in Civil Engineering

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About this book

This book comprises the select proceedings of the Indian Geotechnical Conference (IGC) 2022. The contents focus on recent developments in geotechnical engineering for a sustainable world. The book covers behavior of soils and soil–structure interaction, soil stabilization, ground improvement, and land reclamation, shallow and deep foundations, geotechnical, geological and geophysical investigation, rock engineering, tunneling and underground structures, slope stability, landslides and liquefaction, earth retaining structures and deep excavations, geosynthetics engineering, geo-environmental engineering, sustainable geotechnics, and landfill design, geo-hydrology, dam and embankment engineering, earthquake geotechnical engineering, transportation geotechnics, forensic geotechnical engineering and retrofitting of geotechnical structures, offshore geotechnics, marine geology and sub-sea site investigation, computational, analytical and numerical modeling, and reliability in geotechnical engineering. The contents of this book are useful to researchers and professionals alike.

Table of Contents

Frontmatter

Soil Stabilization, Ground Improvement and Land Reclamation

Frontmatter
Natural Rubber Latex for Reducing Soil Brittleness Induced by Post-compaction Moisture Reduction

High brittleness of soil is an unfavourable characteristic that leads to sudden failure of slopes and retaining structures without warning. Post-compaction drying of soil increases the brittleness, and the scenario becomes critical when shrinkage leads to the development of tensile crack. The present study attempts to use natural rubber latex (NRL) to reduce soil brittleness caused by post-compaction drying. A number of samples with untreated and NRL-treated soils were compacted at dry of optimum and left for natural drying. Unconfined compressive strength (UCS) tests were carried out after drying periods ranging from 1 to 28 days. Soil brittleness is assessed in terms of strain associated with peak strength and energy absorbed before failure. A reduction in brittleness was observed when the soil was treated with NRL. Also, it was observed that the strain at peak strength remains unaffected by the post-compaction moisture reduction in NRL-treated soil. Hence, NRL treatment can be considered a productive technique for mitigating brittleness-induced failure of geotechnical structures.

U. Veena, Naveen James
Study of Reinforced Soil Embankment Supported on Stone Column Improved Ground

In the present paper, a parametric study with the help of numerical modeling is carried out to understand the effect of basal reinforcement using uniaxial geogrid on stone column supported embankment. A comparative study was also performed to understand the embankment behavior with and w/o basal reinforcement (BR). The governing factors such as basal reinforcement tensile stiffness, stone column spacing, soil stratum thickness, soil shear strength parameter, and embankment height are considered for analysis. The two-dimensional (2D) plane strain numerical modeling is carried out with the finite element software Plaxis 2D. Stone column modeling with the gravel trench method and homogenizing method is carried out. From the study, it was found that the influence of stresses acting on stone columns and surrounding soil, settlement profile along the embankment base, stability of the embankment, and horizontal soil deformation beneath the embankment toe are affected by basal reinforcement presence.

Riddhi Gupta, Harish Madupuri
Characterization of Soil–Jarosite Mixes for Geopolymer-Based Soil Stabilization

In this study, an attempt is made to evaluate the compaction characteristics of soil–jarosite (SJ) mixes with an objective to check the feasibility of jarosite as a geopolymer binder for alkali-activated soil stabilization. Jarosite (waste from a Zn smelter) is first characterized in terms of its particle size distribution, specific gravity, Atterberg limits, and microstructure in order to draw comparisons with bare soil. Thereafter, two sets of SJ mixes, one with water and one with an alkali activator solution (NaOH), are then prepared with varying jarosite content. Results from the experiments reveal that jarosite is a silty soil with high plasticity (Ip = 16.71) having 72.8% silt and 26.6% clay-sized particles. Furthermore, the compaction tests revealed a rise in the optimum moisture content (OMC) and a drop in maximum dry density (MDD) with increase in the jarosite content. In addition, SJ mixes prepared with NaOH solution were observed to have lower MDD and higher OMC in comparison to those prepared with water. The findings of this study can be utilized to select a target dry density and OMC for sample preparation required for the strength determination of geopolymerized soil.

Surrender Singh, Abhishek Kumar, T. G. Sitharam
An Experimental Investigation and Numerical Modeling of Glass Fiber-Reinforced Expansive Subgrade Soil With Alkaline Stabilizer

Untreated expansive subgrade soil attains weak geomechanical stability against periodic moisture fluctuation, leading to massive damage on pavement structures. Traditional binders degrade the atmosphere by producing greenhouse gases. This study examines the geoengineering effectiveness of glass fiber composite alkaline binder mixed soil (GF-AS) with different fly ash-sugarcane bagasse ash (SBA) percentages. Alkaline stabilizer (AS) is formed by reacting an alkali solution (NaOH + Na2SiO3) with industrial residual pozzolanic precursors (sugarcane bagasse + fly ash) at 0.4 water-to-solids ratios. The effects of fiber, SBA, and binder doses on the penetration resistance and indirect tensile strength (ITS) in fiber-reinforced soil are quite significant. Mineralogical and morphological studies using powder X-ray crystallography and field emission scanning electron micrographs are conducted to understand the micro surface texture between soil-fiber mixture. The alkaline-fiber soil exhibits higher interfacial bonding and interlocking density compared to lime-fiber soil. A finite element analysis carried out in commercially available software to assess the strength performance of soil with varying binder content in subgrade applications shows that the alkaline-treated subgrade soil exhibits less deformation compared to the lime-treated soil.

Mazhar Syed, Sai Kiran Chukka, Anasua GuhaRay
Stabilization of Kuttanad Soil Using Terrasil Nanochemical and GGBS

Expansive soil has a propensity to contract and expand in response to changes in moisture content, making it less capable of supporting the infrastructure above it and ultimately failing. By enhancing and stabilizing the soil’s characteristics, it can be avoided. Nanomaterials are increasingly influencing our daily lives today. The study is aimed to improve the engineering properties of Kuttanad soil by treating it with nanocompound (Terrasil) as the primary additive and GGBS as the secondary additive. Initially, geotechnical properties of Kuttanad soil were determined. Optimum percentage of GGBS and terrasil was determined using laboratory tests, and it was obtained as 9% and 0.03%, respectively. Finally, the experimental results of prepared soil combinations were analyzed to obtain plasticity, UCS, triaxial and compaction parameters. Addition of optimum percentage of GGBS and terrasil reduced the plastic behavior of soil and increased the UCS and compaction characteristics. PLAXIS 2D analysis was done for the treated and virgin soil to determine the settlement and FOS behavior of soil. From the findings, it was determined that the settlement behavior of treated soil got reduced by 86% and FOS was increased from 1.03 to 2.29.

Aleena Mathew, Nirmal John Joy
Stabilization of Black Cotton Soil Using Red Mud, Phosphogypsum and Lime

Nowadays, the availability of good land for construction has been reduced drastically due to increase in population. Previous soil scientists took extensive efforts to find out appropriate waste material which might be utilized for stabilizing the problematic soil like expansive black cotton soil (BCS) to make it suitable for construction. Expansive soil shows unusual volume change and undesirable engineering behavior when it comes in contact with water. Hence, constructing a pavement over such soil is very vulnerable to damage, requiring high maintenance cost for its repair. In this present study, an attempt has been taken for utilizing the various combinations of phosphogypsum (PG), red mud and lime with black cotton soil to access and improve their geotechnical behavior. The effects of phosphogypsum (PG), lime and red mud treatment on BCS have been investigated in the laboratory by conducting various tests such as California bearing ratio (CBR) test, standard proctor test (SPT) and unconfined compression stress (UCS) test. Considerable improvement has been noticed in the value of UCS and maximum dry density (MDD) when 2% of PG was added to mix of BCS and red mud in the ration of 3:2, whereas the CBR value was found to be maximum when 5% of lime was added to the mix.

Sanjeet Sahoo, Bithika Ghosh, Janarul Shaikh, Krutideepan Kar, Subhakant Pati
A Study on Recycled Plastic Pins as Micropile in Stabilization of Cohesive Slope

Stabilization of cohesive slope is very important on large-scale infrastructure projects as there is always an inherent tendency of slope failure causing threats to life and property. The aim of this research work is to utilize waste plastic for stabilization of earthen slope. For this, recycled plastic pins, made up with recycled plastics, sawdust and fly ash are used as micropile. Experiments were conducted in a model cohesive slope with slope angle 30º made inside a steel tank of dimension 1 m × 1 m × 1 m. Two different diameters (d) of micropiles, 22 mm and 30 mm are used in two lengths, 20d and 30d and at three different spacings 3d, 4.5d and 6d. Four number of micropiles are arranged in a row along the slope in an A-frame with inclinations 0º, 5º, 10º and 15º with vertical. The load-settlement behavior of micropile groups is studied under static axial vertical compressive load. The ultimate load carrying capacity of micropile group under specific settlement is determined from experimental observations. Plaxis-3D models are also developed to validate the experimental results. It is observed that the load carrying capacity of a micropile group increases with the increase in diameter, length, spacing and inclination of micropiles.

Vinu Sunny, Nirmali Borthakur
Effect of Fly Ash and Synthetic Fibers on the Desiccation Cracking of Expansive Clay

Expansive clays are abundant in many strategically important places in India. They undergo volumetric changes by swelling and shrinkage upon seasonal moisture variations. The hysteresis of swelling and shrinkage leads to desiccation cracking, loss of shear strength, change in consolidation characteristics, increase in permeability, and seepage characteristics. Generally, these soils are replaced with a more desirable material for construction. This study aims at sustainable use of expansive clay from Surat in barrier systems as the clay possesses permeability of the desirable range of 1 × 10–9 m/s. Expansive clay was mixed with fly ash and reinforced with discrete and randomly distributed polypropylene fibers of length 12 mm and varying fiber contents. The tensile strength behavior of fiber-reinforced expansive clay was studied by performing desiccation cracking and direct tensile strength tests. The desiccation cracking tests were performed under controlled environmental conditions. The results indicate 89.9% of crack reduction due to the presence of reinforcing fibers and fly ash. The bridging action of fibers increases the tensile strength of clay and prevents cracking of expansive clay, thereby maintaining the integrity of the clay layer.

Uma Chaduvula, Purvi Agrawal, Rashi Desai, Swati Bharti
Performance Assessment of Waste Plastic Inclusions on the Strength of Expansive Clays Blended with Vitrified Polish Waste and Lime

Expansive clays will tend to increase in volume as it absorbs water and lessen in volume as water is drawn away. Foundations, building structures, pavements may crack (or) heave as the underlying expansive clays become wet and swell. Thus, for safe design, such weak soils need to be improved before construction. Various techniques are available in practice, and one of these processes of improving the properties weak or soft soils is stabilization. On the other hand, collection of different industrial waste materials is a major concern to the environmentalists. Vitrified polish waste is a waste from ceramic industry and it requires effective disposal, because it contaminates the environments, creates dust in the summer, and endangers agricultural and public health. Today plastic is one of the major toxic pollutants because of its nature of non-biodegradable composed of plastic pollutes and toxic chemicals. During its production and disposal, plastic causes severe damage to the environment. The main importance of the present study is to assess the use of new industrial waste material vitrified polish waste, different waste plastics, and also a binder lime. To understand the performance of stabilized soil, laboratory tests like Atterberg’s limits, compaction parameters, swell and strength parameters were studied. The outcome revealed an encouraging performance and the efficiency of the added materials. The optimum combination was 6% lime, 20% vitrified polish waste, and 1.0% waste plastic inclusions which gave the improvement in strength characteristics. Thus, from this experimental study, a twofold solution was evolved, i.e., resolving the problem of disposal of waste and also improving the strength properties of problematic expansive soil.

D. Appanna, L. N. V. N. Varaprasad, B. Varaprasada Rao, R. DayakarBabu
Performance of Stone Column Subjected to Dynamic Loading in Sand Bed

The objective of this paper is to study the effect of dynamic loading on machine foundation and to compare the settlements of machine foundation with different types of stone columns. The Shaking table test is used throughout the study to investigate the effect of dynamic loading on machine foundation on soil bed with respective stone columns, i.e., ordinary stone columns (OSC), encased stone columns (ESC), and reinforced stone columns (RSC) using a series of laboratory-scale model tests. Furthermore, the effect of various parameters such as length and diameter of stone column, amplitude of vibrations on the settlement of machine foundation supported on soil bed are with an OSC, ESC, and RSC are compared. From the result, it is evident that encased stone columns are more effective as compared to ordinary stone column and reinforced stone column, toward reducing the settlement of footing subjected to dynamic loading.

D. V. Khedkar, A. I. Dhatrak, S. W. Thakare
Utilization of Brine Sludge to Improve the Strength and Compressibility Characteristics of Soft Clays

Stabilization of soil is a method to enhance the properties of soil by mixing and blending other materials. In past decades, efforts have been made to utilize the by-products of industrial waste such as blast furnace slag, fly ash in large scale, to stabilize soils. An inefficient treatment and disposal practice of industrial waste cause serious damage to the environment. Therefore, the proper use of these wastes is highly advisable for ensuring a clean and safe environment. This paper aims to make use of the waste generated from a major industry located in Kochi for the purpose of stabilization of soft marine clay. The waste, known as ‘Brine sludge,’ is generated during the manufacturing of caustic soda and chlorine through electrolysis of brine. This study explores the potential use of brine sludge in soil stabilization. In the present work, brine sludge was mixed with marine clay at various percentages of 10, 20, 30, and 40% by dry weight of the moist clay. In an attempt to determine the effect of a calcium-based stabilizer on brine sludge-stabilized clay, 3% of lime was added with brine sludge-treated clay specimens.

Merin Kuriakose, K. N. Athira, Benny M. Abraham, Sobha Cyrus
Application of Biopolymers in Geotechnical Engineering Practices: An Eco-Friendly Approach

Before construction, it is necessary to improve the engineering characteristics of soft soil. The most common technique, cement stabilization (either alone or in combination with other methods), causes a number of environmental issues. Approaches have been explored to replace the conventional methods of soil stabilization. Biopolymers an eco-friendly material is one of the sustainable solutions as an alternative for soil improvement. In the present study, interaction with biopolymers, i.e., xanthan gum with week soil is studied. From the results, it is found that biopolymer enhanced the geotechnical properties of the week soil. The enhancement varies with the percentage of biopolymer added to the soil. In this study, 0.5, 1, 1.5, 2, and 2.5% of xanthan gum added to week soil. Their effect on the week soil, strength improvement was investigated. Index properties, unconfined compressive strength, and resilient modulus are determined. A very minimal fraction of biopolymer increases the mechanical properties of the soil. Therefore, biopolymer has a very strong potential to replace cement as the conventional soil binder in context of development to replace the conventional method.

Rakesh Pydi, Laxmikant Yadu, Sandeep Kumar Chouksey
Utilization of Gondegaon Coal Mine Overburden Dump as a Construction Material

Opencast mining is done dominantly all over the world. During these mining operations, huge amount of overburden (OB) is generated. The higgledy-piggledy management of this overburden can result in substantial issues which may adversely affect safety and production of the mine. Failure of this overburden dumps consequences in loss of life, production and impact on the neighboring amenities. This research aims to stabilize the OB dump as well as assess its utilization in the construction industry by adding optimal dose of industrial by-product. Hence, the study is done on this aspect at Gondegaon Opencast Mines under the administrative control of Western Coalfields Ltd. This study investigates the critical parameters of OB dump and industrial by-product with different doses for examining the suitability in construction activities for sustainable development.

Atul D. Gautam, L. K. Yadu
Comparison of Different Ground Improvement Techniques for the Road Construction Over Kuttanadu Clay Strata

Kuttanadu clay is infamous for its very low shear strength and permeability. As a result, the construction of embankment over this stratum invites a lot of trouble including bearing capacity, settlement, and stability issues. To arrest these issues, proper ground improvement technique needs to be selected, which in turn is also governed by the construction cost, time, and practical feasibility. One such case study is the upgradation of Alappuzha-Changanassery road, where the height of the road level is proposed to be increased to tackle the issue of complete submergence during monsoon. In the present study, an attempt has been made to compare different ground improvement techniques in terms of stability, total settlement, and construction time. These techniques include prefabricated vertical drains (PVD) and lightweight filling using geofoam. The 1D consolidation and finite element analysis of these techniques were carried out using Midas Soilworks software, and the results were compared with the embankment construction without any ground improvement technique. The study inferred that the lightweight filling using geofoam blocks is the most efficient technique in terms of construction time, settlement, and stability.

Abhijeet Kumar, Parvathi Geetha Sreekantan
Efficacy of Cross-Linking of Biopolymers in Soil—Stabilization

Soil stabilization relying on sustainable methods like BPST (biopolymer-based soil treatment) has been gaining attention in the recent past. These biopolymers form a hydrogel between soil and pore water, and the durability of hydrogel is affected under varying conditions. Cross-linking of biopolymers addresses this issue by forming hydrogels of enhanced physical and mechanical properties. In this present study, xanthan gum (XG) and guar gum (GG) were cross-linked with varying percentages (i.e., 1% GG and 2% XG) to treat clay of high plasticity. The performance indicators include Atterberg limits, standard proctor compaction test, unconfined compressive strength (UCS) test and permeability tests. The test results have shown an increase in Atterberg limit values with an increase in the percentage of cross-linked biopolymer dosage. The standard Proctor test results reveal that the maximum dry density (MDD) of soil decrease, and the UCS test results show an increase in the UCS value, which is attributed to the suction of the soil specimen. Moreover, the coefficient of permeability (k) values decreased due to the filling of pore spaces with hydrogels.

M. Ashok Kumar, Arif Ali Baig Moghal, Jagadeesh Bommisetty, Nuruddin Mohammad
Shear Strength Behavior of the Flyash-Treated Lime Columns on Expansive Soils

Expansive soils are the most problematic soils for civil engineering constructions. In recent years, rapid growth in population results in construction of multi-storied buildings in even problematic soils to meet their needs. Hence, the stabilization of expansive soils is necessary to improve expansive soil mechanical properties. As a civil engineer, one should deal with such problematic soils in a proper way because any mistakes in the soil study lead to hazards. The objective of this work was to investigate the mechanical properties of flyash-treated lime column stabilized expansive soil which is the best solution for civil engineering works which are undertaken in the expansive soil stratum. Remolded compacted clay soils were prepared in tanks with lime columns and flyash-treated lime columns installed in them. The soil samples are extracted after curing and properties of the samples were investigated as a function of flyash content added and curing periods. It was observed there are significant changes in the shear strength of treated soil due to the reactions between soil and flyash–lime.

G. Gnana Prasanna, M. Manoj Kumar, A. Dhanaraj, K. Raja Sekhar
Numerical Analysis of Stone Columns in a Layered Soil System

Stone columns are mainly used to improve the bearing capacity of soft soil. It reduces the settlement as well as imparts stability to different geotechnical structures constructed on it. When huge structures such as oil storage tanks, embankments and multi-storey buildings are constructed on soft soils, the ordinary stone column alone will not be sufficient to bear the load coming on to it. Therefore, encased stone column is preferred over ordinary stone column during such construction. In view of that numerical analysis has been carried out to investigate on the bearing capacity of ordinary stone column and encased stone column in layered clayey soils. The numerical model of ordinary stone column and encased stone column were simulated using finite element package PLAXIS3D. Parametric study has been carried out, and their response on the overall bearing capacity has been reported. It is found that the bearing capacity of improved ground is mainly influenced by the presence of topmost layer up to a depth of 4 times the diameter of stone column in layered clayey soil.

Subhash Kumar Gupta, Soumen Naskar, Awdhesh Kumar Choudhary
Stabilization of Red Mud Using Mineral Precursors by Geopolymerization Process

Red mud (RM) is an alkaline industrial waste product generated during the processing of bauxite by Bayer’s process. Red mud is high alkaline, exceedingly caustic and harmful to soil and biological forms posing a significant disposal challenge. The alkalinity of red mud can be successfully utilized to initiate geopolymeric reaction with industrial waste materials rich in alumino-silicates to stabilize the red mud. In this study using mineral precursors like granulated blast furnace slag (GBFS) and rice husk ash (RHA), an attempt has been made to stabilize red mud. The quantity of GBFS and RHA is varied as 0, 5, 10, 15, and 20% by weight of the RM–GBFS and RM–RHA mixes. Further, additional doses of alkali (NaOH) solutions of 1, 2, and 4 M concentrations are added to accelerate the geopolymerization process. The plasticity properties, compaction characteristics, swelling, and strength properties of treated red mud were determined at different curing periods. A noticeable increase in strength was observed with addition of mineral precursors, doses of alkali, and curing period. Mineralogical analysis endorses the formation of geopolymeric products which improve the geotechnical properties in addition to encapsulating the metallic ions present in virgin red mud. Atomic absorption spectroscopy (AAS) analysis also confirms reduction in the concentration of metals in leachate of stabilized red mud.

Suresh Prasad Singh, Sourav Sarkar, Sarthak Rana
Assessment of Desiccation Cracks in Soil Fused with Biochar and Dolochar Using Digital Image Processing

The expansive soils exhibit high swelling and shrinkage characteristics, cracking, and stickiness which causes poor yielding of crops and high seepage of ground water through concerned soil. The cracking resistance of soil can be enhanced to maximize the yield and control seepage. In the present study, industrial waste biochar and dolochar was added with locally collected soil to assess the effects of those sustainable materials on engineering properties of soil as well as on enhancing the cracking resistance. Atterberg limits, free swelling index, compaction characteristics, and unconfined compressive strength tests on expansive soil were carried out at three different biochar contents (i.e., 2.5, 5, and 10%) and three dolochar contents (i.e., 5, 10, and 20%) added with bentonite. The development and proliferation of fractures in a desiccated soil specimen were captured using a digital image capturing device and processed. The results showed that at 5% biochar and 10% dolochar, optimum values were obtained. The crack intensity factor (ratio of the area of the cracks to the total specimen area), the average width, and the total area of cracks decreased with increasing biochar up to 5% and dolochar up to 10%, thereby increasing the relative integrity of the specimen.

Prasanna Kumar Behera, G. Suneel Kumar, Vamsi Alla, Arnab Ghosh, Rabi Narayan Behera
Behavior of Soft Clay Treated with Vibro Stone Columns Under Earthen Embankment Loads—Field Study

Construction of high earthen embankments on soft clays experiences geotechnical concerns. In the present case,performance of a 10-m-high earthen embankment constructed over marine clay treated with vibro stone columns is studied. The subsoil below earthen embankment consists of 13m thick soft clay which cannot support required loadings. A selected portion of embankment was fully instrumented with settlement gages, inclinometers, and piezometers for monitoring its performance. The present study discusses the observed results with respect to design soil parameters and its behavior of treated soft clays. In addition, pre- and post-ground improvement soil investigation test results are reviewed to confirm improvement of soil stiffness. Pre-and post-soil investigation results clearly indicate improvement of shear strength and soil stiffness of the treated ground. This implies more than 1/10 reduction in the estimated service stage settlement compared to unimproved case.

Anurag Chafale, B. Govind Raj, Madan Kumar Annam
Control of Shrinkage Characteristics of Expansive Soil by Using Low Compressible Soils

The expansive soils constitute most of the soil types found in India. The use of expansive soils presents serious challenges to the geotechnical engineer as they can lead to excessive settlements and therefore be injurious to the health of major civil engineering structures such as embankments and nuclear power plants. Therefore, understanding the composition of fine particles becomes very important in the geotechnical field, including mineralogy. An expansive soil sample was taken for the purpose of study of shrinkage factors including shrinkage limit and free swell index, and the effect on the various soil parameters was observed. In this study, an attempt has been made to reduce the excessive potential of the expansive soil by adding different proportions of low compressibility soils such as 10, 15, 20, 25, 30, and 35% by weight. The analysis of the test results presented in this paper shows that the shrinkage limit and free swelling index are satisfactory and indicate that adding low compressibility clays can reduce the expansive potential of soils, thereby improving their compressibility characteristics. So that the properties of highly expansive soils can be altered with the help of low compressive soil mix in those areas. Such a quick process helps to find solutions to make complex soils suitable for the civil engineering structures.

R. K. Bharti, H. Prakash, S. Noor, M. Gupta, R. Chitra
Effect of Microbial Enzyme on Fly Ash and Assessment of Compressive Strength

Microbial-induced calcite precipitation is an emerging technique in the field of soil stabilization techniques. In the present ongoing study, the stabilization of fly ash is investigated through the MICP process. Sporosarcina pasteurii, a natural urease enzyme producing bacteria, has been considered because previous studies demonstrated that Sporosarcina pasteurii has a high urease enzyme producing capacity and can hydrolyze more than 90% of urea in a comparatively shorter time span. A urease enzyme is a type of enzyme that hydrolyzes urea and precipitates it as calcium carbonate (CaCO3). Two different cell concentrations of these microbes at OD600nm (0.8) along with a binding solution of urea and calcium chloride passed through a fly ash column of length and diameter (2:1) ratio. After microbial treatment, fly ash samples were subjected to an unconfined compressive strength (UCS) test. The test results show improvement in UCS value with treatment. The precipitation of calcium carbonate is the key material which binds with fly ash particles. The goal of this study is to look at fly ash as a building material and see if it can be used in the field.

Joyprakash Naskar, Anil Kumar Sharma
Stabilization and Durability Analysis of Medium Compressibility Clay Using Rubber Fibers

The in situ soil should bear the load, but at certain instances more adverse conditions may lead to failure of soil and hence can lead to consequence failure of the structures. To avoid these failures, understanding of soil behavior to different loading conditions is essential, thereby arising the need for studying and finding appropriate alternatives. One such alternative is soil stabilization. Tons of rubber waste are produced annually, not only problematic for disposal, but also increase environmental pollution and health risks. The consumption of rubber as an alternative to construction materials can effectively minimize environmental pollution. In this study, rubber fibers in different proportions were added to investigate the effect of rubber fibers on compaction, UCS, CBR, and durability properties of intermediate compressible clay. The tests were conducted on samples with inclusion of rubber fibers in different proportions of 0, 0.5, 1, 1.5, 2, and 2.5%. A comparison was made between light and heavy compaction test. Samples showed decrement in OMC and MDD. Inclusion of rubber fibers with proportion of 1.5% to intermediate compressible clay showed maximum increment in UCS and CBR values, and durability was improved due to decrement in weight loss of the specimens in subsequent freeze–thaw cycles.

K. L. Venkateshwara Reddy, Suresh Prasad Singh
Improvement of Soft Ground Using Nano-Chemical Stabilization

Soft clay soils spread over larger areas of Kerala are very weak to support the overlying structures. The need to stabilize these weak soils arises for the desired strength improvement. A series of unconfined compressive strength (UCS) tests have been performed on untreated and nano-chemical treated clay soil samples to assess the effectiveness of a nano-chemical as a soil stabilizer. Herein, a nanotechnology-based organosilane compound (terrasil) is introduced into the clay in various amounts of 0.03, 0.04, 0.045 and 0.05% of the dry weight of soil taken for stabilization. The study aims to determine the optimum dosage of nano-chemical corresponding to the maximum UCS after 7 and 14 days of curing. The results indicated that the UCS of stabilized soil increased with the increase in nano-chemical dosage. But the increase in strength was high up to a specific dosage, and further, the growth rate decreased. The images obtained from scanning electron microscopy (SEM) support the mechanism behind the strength improvement of nano-chemical-treated clay soils. The chemical interactions between nano-chemical and clay soil make strong bonding and fill the pore spaces. Soft ground with nano-chemical treatment has the advantages of lower cost and better environmental protection. The findings will help improve the strength of weak foundation soils, embankment dykes, and road pavements.

Regi P. Mohan, K. Rangaswamy
Numerical Modeling on Behavior of Annular Stone Column in Layered Soils

In the past, many studies on the improvement of soft soils to increase the load-carrying capacity and reduce settlements found that ordinary and encased stone columns have been increasingly used. In this present work, an annular-structured stone column is introduced into the ground to study the behavior of the column in layered soils. Two types of layering systems, i.e., soft clay overlying stiff clay and vice versa, are considered for the present study. To know the performance of an annular stone column, numerical models were carried out by taking the internal and external diameters of 40 mm and 80 mm, respectively, with geo-reinforcement and varying the thickness of the top layer as well as the bottom layer. To know the load-carrying capacity of an annular stone column by giving a prescribed displacement, a detailed parametric study was carried out using the finite element-based software Plaxis 3D. For the soil and stone columns in the numerical analysis, the elastic-perfectly plastic Mohr-–Coulomb failure criterion with drained and un-drained conditions was used.

Panuganti Aditya, Boya Manikanta Reddy, M. Heeralal
Performance Assessment of Treated Jute Fiber Encased Stone Columns in Improving Soft Clay Beds

Stabilization of soils becomes an important concern in preparing the soils before construction of structures. Especially, in soft clayey soils or soils near to coastal region, i.e., soft marine clays, the ground improvement becomes essential so that there is an improvement in bearing capacity and reduction of settlement due to the applied loads. This paper presents the results of experimental tests done on laboratory scale model of a sample of compressible soil specimens reinforced with conventional stone columns, treated jute fiber encased stone columns and comparison is done with these with reference to soils without any stone columns. The core objective is to evaluate the bearing capacity and settlement behavior of the soils which are reinforced with conventional stone columns, treated jute fiber encased stone columns. The experimental results have been compared with existing statistics proposed in the literature. The specimen consists of soft clayey beds that are reinforced with stone columns prepared with HBG (hard broken granite) metal with sizes between 2 to 6.3 mm. The results show that the increment in bearing capacity and decrement in settlement of soil is found out when the soil is reinforced with the stone column encased with treated jute fabric.

Venkateswarlu Dumpa, G. V. R. Prasada Raju, R. Dayakar Babu, A. M. N. Kashyap
Electrokinetic Remediation of Copper- and Zinc-Contaminated Soil Using Carbon Nanotube

Contamination of soil and groundwater is turning out to be a serious global environmental problem. Due to their poisonous and non-biodegradable character, various contaminants such heavy metals, petroleum hydrocarbons, pesticides, and other persistent organic pollutants are complicated in nature. As a result, there is an urgent need to develop remediation solutions that are both affordable and long-lasting. One of the most effective methods for removing metal ions from contaminated soil is electrokinetic remediation (Gomes et al. in Centre Environ Sustain Res 6545–6535, [1] ). It is an effective and innovative technique for remediating a variety of soil types, particularly low permeability fine grain soils like silty and clayey soils. In this technique, a contaminated soil is subjected to a direct-current electric field, which causes multiple kinds of transport events, including electroosmosis, electromigration, and electrophoresis. The current experimental investigation aims to analyze the effectiveness in copper and zinc removal from contaminated soil by electrokinetic remediation utilizing CNT. Clayey soil was tested in a lab environment using a direct-current (DC) electric field. The electrokinetic remediation was improved with the introduction of CNT. From 28.5% to 94.6% more copper and from 20.0% to 92.5% more zinc was removed respectively. The rise in removal effectiveness suggests that CNT can be used to treat copper- and zinc-contaminated soils electrokinetically.

Aiswarya Chandran, Sobha Cyrus, Anil Joseph, G. Sanoop
Parametric Studies on Cemented Stone Column Using Demolition Waste Materials

With rapid urbanization and industrialization in the recent times, the available useful land is diminishing for development of the commercial, industrial and transportation purposes particularly in the urban areas. This necessitates the use of land having weak strata particularly soft soil deposits. To minimize the construction problems associated with these soils, ground improvement is done quite frequently on the sites. Among the numerous ground techniques adopted to improve properties of the weak soils; use of stone column is one such approach used widely for several applications in the fields. The concept of stone column installation involves replacement of 10–35% of weak soil with another gravelly material to form a stiffer composite mass of granular cylinder. In the present study, an exhaustive laboratory testing work was undertaken to study the improved strength properties of soft clay soils collected from Nagpur City, Maharashtra State, India on insertion of stone column. Stone columns are placed single and in group with triangular arrangement. Demolition waste material is attempted as a replacement to the natural aggregate with marginally small doses of cement for stone column preparation. Further the effects of varying length (L) to diameter (D) ratios (i.e., L/D ratio) of stone columns on the strength properties were analyzed. The study shows an overall improvement in the load carrying capacity of clay beds on insertion of stone columns. Laboratory testing program confirms the possible use of demolition waste for stone column construction as the strength improvement is nearly 60–75% of the natural aggregate stone column.

P. P. Dahale, S. S. Geete, T. N. Singh, K. H. Singh
A Comparative Study on the Uplift Capacity of Single Helix Helical Anchor and Granular Pile Anchor in Sand

Helical anchors are tension members widely used to provide tension resistance to structures that are prone to uplift. A relatively new method called granular pile anchor is a modified form of a conventional stone column with an anchor plate at the bottom connected to an axial rod that can provide tension resistance when connected to the base of a structure footing during uplift. In this paper, experimental investigations on the uplift behavior of laboratory-scale model helical screw anchors and granular pile anchors installed in loose sand bed under the influence of vertical uplift loads are presented. The model anchors were subjected to a constant uplift strain, and the uplift resistance and the uplift displacement were measured during the experiment. The model helix/anchor diameter was kept as a constant of 70 mm, and the effect of embedment ratio (length to diameter ratio) on the uplift capacity and uplift behavior are studied and reported. A granular pile anchor was found to provide significantly larger uplift resistance compared with a single helix helical anchor and may be used as an alternative or in addition to it.

Jerin Joseph, Shailendra Kumar, Jignesh B. Patel, Yogendra Tandel, S. Ravi Teja
Utilization of Steel Slag for Stabilization of Subgrade Soil

As a developing nation, India is presently undergoing transformation. With rising population and rapid urbanization, demand for sustainable transportation facilities is skyrocketing. Highway engineers frequently struggle to find the right material for highway construction. On other hand, rapid urbanization has led to a surge in infrastructure and development projects, skyrocketing steel consumption. India is the second-largest steel producer, trailing only China. Integrated steel plants in India produce 2–4 tons of slag per ton of steel, which is then stock-piled. Waste disposal in an environmentally friendly manner is a major concern. Current study investigates possible utilization of steel slag for stabilization of dredged soil when used along with traditional stabilizing agent. Proposed study helps identify the effect of addition of slag and cement on strength characteristics of composite mix. It is also extended to investigate the effect of curing on strength characteristics. Current study also tries to analyze the effect of providing 500-mm-thick stabilized capping subgrade on design parameters such as vertical compressive strain, horizontal tensile strain at critical locations with the help of IITPAVE software.

Aditya D. Ahirwar, Hemant S. Chore
Strengthening of the Foundation Using Deep Mixing and Stone Column Techniques for Large Earth Cum Rock Fill (ECRF) Dam for an Irrigation Project

A Large Earth Cum Rock Fill, ECRF Dam is under construction in the state of Andhra Pradesh in India. The Embankment crest width of the dam is 12.5 m and base width is of approximately 136.75 m with a stepped sloping height of 27 m on both upstream/downstream sides. Plastic concrete diaphragm wall of 1.2 m thick is constructed along the longitudinal central axis to avoid seepage to depths of 96 m below the existing bed levels. The functional efficiency of plastic concrete cut-off wall is designed for the high underwater scouring and discharge velocity of river during the peak flood season. Deep single mixing (DSM) columns and stone columns are evenly arranged under the footprint of ECRF dam for smooth transition of stresses by gradually reducing stiffness moduli from Centre to Toe of Embankment. The stiffness moduli reduce gradually toward the Toe facilitating settlements within allowable limits. The paper discusses the installation of the DSM columns along the diaphragm wall and field trails carried out for establishing the desired stiffness modulus of DSM columns.

Vidyaranya Bandi, Karsten Beckhaus, Cemal Can Maslak, Vijaya Bhushan Rao
Drilled Displacement Columns as Ground Improvement in San Francisco

Drilled displacement columns (DDCs) can improve loose granular soil and transfer loads through weak soil. DDCs and the improved soil surrounding the DDC act as a composite system supporting structural elements, such as foundations and slabs. DDCs use a displacement drill tool to displace and densify granular soil laterally, resulting in improved soil and fewer spoils during installation. DDCs can increase bearing capacities, reduce settlement, and increase soil’s resistance to liquefaction. This paper discusses the benefits of DDCs as ground improvement elements and provides a case study of a project in San Francisco, California. In this project, DDCs were installed to reduce foundation settlement and transfer building loads to a deeper bearing stratum. To confirm the adequacy of the DDCs, load tests were performed on four test elements to ensure they could support the anticipated loads with an acceptable settlement.

Akhil Anil, Daniel Wagstaffe
A Review on Biopolymers as an Eco-Friendly and Sustainable Solution for Soil Stabilization

The impact of traditional stabilization method on the soil is now a major concern for all the researchers. The amount of carbon dioxide emitted by cementitious materials in the soil has made global researchers to think about materials quite sustainable that are eco-friendly too. While considering sustainability, there has been ample number of choices for soil stabilization. However, all the sustainable materials are not considered as eco-friendly and delivers an adverse effect to the soil. To overcome these adverse effects, bio products are introduced into the soil which has a promising future in the field of sustainable geotechnics. In this review paper, the center of attraction is biopolymer, an eco-friendly material which is derived from sources like plants, animals and microorganisms. There are enormous materials which are extracted from nature, a very few are commonly used in the field of soil engineering. Though biopolymers, such as Xanthan and guar gum have shown immense increase in the strength of soil when added in different proportions. When compared to traditional material with biopolymer, a very less amount is require to attain the comparable strength. Biopolymer has proved itself to be versatile in the strength property but was found to be lacking behind when brought in contact of water. Biopolymers for stabilization are suitable for cohesive and cohesion- less soil with higher strength, which makes it the best option in place of traditional technique.

Neha Raj, S. Selvakumar
Characterization of Chicken Feathers Ash as a Potential Soil-Stabilizing Material

As a byproduct of the poultry meat processing industries, huge quantities of chicken feathers are produced. The methods utilized to dispose of chicken feathers from these industries and abattoirs are expensive and not sustainable. The study aims to examine the chemical composition and cementitious properties of a chicken feather, and its fractions in ash form (as a powder and flake). The morphological, structural, and chemical properties of the prepared chicken feather ash powder and flakes are analyzed through XRF, XRD, and SEM. This experiment is carried out to compare the changes in chicken feathers when it turns to ash powder and the flake structure after the incineration process. The incinerator to convert waste chicken feathers to ash powder and flakes is designed with a carbon filter to reduce the environmental impact. Results indicate that feather ash powder contains lime content in the form of CaO, i.e., 39% which can act as a good stabilizing material in soil compared with the chicken feather ash flakes that contain a high amount of wollastonite that comprises small traces of iron, manganese, and magnesium substituting calcium. Also, the optimum temperature of 600 °C is derived to convert the chicken feathers into ash form with a high level of calcium carbonate and silica. The study concludes that the chicken feather ash powder is recommended as a soil-stabilizing material over the flake due to the higher amount of pozzolanic material in the chicken feather ash powder (CFAP) than the chicken feather ash flake (CFAF). Thus, chicken feather waste can be turned to be potential soil-stabilizing material by converting it into ash form.

R. Kokilan, B. Divya Priya
Metadata
Title
Proceedings of the Indian Geotechnical Conference 2022 Volume 4
Editors
Babu T. Jose
Dipak Kumar Sahoo
Anand J. Puppala
C. N. V. Satyanarayana Reddy
Benny Mathews Abraham
Ravikiran Vaidya
Copyright Year
2024
Publisher
Springer Nature Singapore
Electronic ISBN
978-981-9717-53-8
Print ISBN
978-981-9717-52-1
DOI
https://doi.org/10.1007/978-981-97-1753-8