Proceedings of the Indian Geotechnical Conference 2019

Inhaltsverzeichnis

1. Frontmatter

2. Analysis of the Effect of Plastic Waste Strips on Characteristics of Fine-Grained Soils

   Mouneesh Meka, Anjan Patel

   Abstract

   Most of the developing countries like India are facing a severe crisis in solid waste management. Among all, plastic waste is considered to be more harmful because of its non-biodegradable nature and abundant usage. The current work deals with an engineering technique in order to eliminate this problem of plastic waste management, by using plastic waste as a potential reinforcing element in soils. This saves a lot of effort, intellect and money which would be otherwise invested to manage plastic waste from various sources. In this study, the effects of mixing low-density polyethylene (LDPE) strips on some of the physical properties of fine-grained soils are presented. These LDPE strips act like reinforcement for the soils and could be well used in the construction of embankments and roads. In the present analysis, unconfined compressive strength (UCS) test, proctor compaction test and bender/extender tests were conducted. Four different types of fine-grained soils (i.e., CH, CL, MH and ML) were taken, and five different percentages by weight (i.e., 0%, 0.25%, 0.5%, 0.75% and 1%) of LDPE strips were added to each of these soils. The optimum percentage of LDPE strips that result in maximum improvement of soil characteristics was evaluated. It was observed that the UCS value increases up to a certain percentage of plastic waste and then it starts decreasing. Poisson’s ratio was found to decrease with increase in plastic content, thus increasing the soil stiffness.

3. Siting of New Landfill for Municipal Solid Waste Using GIS and MCDA-A Review

   Swati A. Patil, Mahesh S. Endait

   Abstract

   Due to rapid change in urban areas and the exponential growth in population, accelerated the huge generation of municipal solid waste (MSW). The management of the disposal of MSW is a substantial and complex process. Landfilling is the most common method used for the disposal of MSW, at the same time identifying the suitable site for disposal of MSW is a difficult task. Stakeholders are very much concerned about the disposal of solid waste and its landfilling. Sitting of the new landfill using spatial data and Geographical Information System (GIS) approach on conflicting points among social, economic and environmental effects. In this review paper literature related to new landfill sitting using GIS and Multi-Criteria Decision Analysis (MCDA) methods are cited. Review paper concentrates on MCDA techniques, method of disposal, type of solid waste and country.Most common methods have been used by researchers are Analytic Hierarchy process, Fuzzy, Dynamicmodeling, Analytical Network Process, Analytic Neural Network, site screening method and Artificial Neural Network. It can be concluded that GIS provides accurate mapping, quick collection of data, high accuracy, better predictions, and analysis by eliminating unsuitable areas.Moreover, MCDA methods Analytic Hierarchy process(AHP) is found best from a set of available alternatives and gives the error-free solution to the users because of simplicity in pairwise comparisons,consistency in evaluation and versatility. It helps inidentifying the optimum site for the construction of a landfill. Limitations of AHP are found in random assumptions for various criteria and due to that consistency ration increases more than10%. Hence, there is a need forthe application of artificial intelligence with AHP.

4. Performance Analysis of GCLs as Barriers-A Review

   Nazeema Basheer, Jaskiran Sobti

   Abstract

   Geosynthetic clay liner has been used over a decade to stave off problems such as leaching of hazardous chemicals from landfill containments which otherwise could cause ecological issues and endanger the environment. Low permeability is a highly desirable property for use as a liner material in landfills to effectively control the seepage of highly contaminated leachate which can pollute the soil and groundwater in the vicinity. GCLs contain bentonite essentially, which has a high montmorillonite content imparting swelling characteristics. The usage of GCLs is booming day by day in engineered landfills and they are being extensively researched on their different characteristics such as hydraulic conductivity, diffusion characteristics, mechanical properties, reaction to various chemicals, and durability. This paper presents an overview of the major findings on the critical aspects affecting the various characteristic properties of GCLs. The performance of GCLs upon coming in contact with a higher concentration of salts considering the actual composition of leachate has also been dealt in this study.

5. Effect of Alkaline Environment on the Swell Pressures of Compacted Bentonite Under Thermal History

   Rohini C. Kale, Kapil Bhanwariwal, K. Ravi

   Abstract

   Bentonite is used as a buffer material in the deep geological repository for the safe disposal of high-level nuclear waste (HLW). The repository consists of a natural barrier system and an engineered barried system. Natural barrier system consists of a host rock and its surroundings and engineered barrier system consists of a buffer material as well as a waste canister. Bentonite is compacted around the waste canister to isolate it from the atmosphere as well as to provide long-term stability to the barrier. The high temperature (150–250 °C) of the waste canister reduces over thousands of years till the radioactivity of the waste degrades as well as while the long-term operation of the repository, the concrete components will deteriorate and produce alkaline fluids having pH > 12. This long-term influence of high temperature may create a thermal history on the compacted bentonite, and the highly alkaline solution may alter the bentonite near the concrete affecting the physical and chemical properties of compacted bentonite. Hence, it is necessary to investigate the influence of alkaline environment along with the induced thermal history on the swelling pressure of compacted bentonite. The paper discusses an assessment of swell pressures of compacted bentonite [Barmer 1 (B₁)] from Barmer district of Rajasthan, India, with an initial dry density of 1.5 Mg/m³ and subjected to 110 °C, hydrated with cement solution and distilled water. The swelling load is recorded with the help of digital load frame and compared with non-heated samples of the same density. The swelling time data of compacted bentonite is presented and compared. Experimental evidence indicated that the swelling pressure of compacted bentonite was less when hydrated with cement water as compared to distilled water. But the time taken for saturation was more when hydrated with cement water as compared to distilled water. However, further investigation is required to understand the swelling mechanism under highly alkaline solutions.

6. Utilization of Municipal Solid Waste as Backfill Material

   Parul Rawat, Supriya Mohanty

   Abstract

   One of the major problems in developing India is waste generation and its management. The total municipal solid waste generated by urban India is about 68.8 million ton per year and which is likely to be increased up to 160.5 million ton per year by 2041. Agricultural wastes like rice husk ash, and organic fibers and industrial wastes like fly ash, slag, and silica fumes which are also a part of solid waste are already being used in various civil engineering purposes. The paper is focused on the analysis of geotechnical use of municipal solid waste as backfill material in a cantilever retaining wall. Retaining walls are stabilizing structures that hold the soil at different levels without sliding of backfilled soil. In this study, conventional backfill soil of a cantilever retaining wall is replaced by MSW material, and stability analysis has been performed using Geo5 fine software. Then, stress and settlement analysis of the retaining wall under static and seismic condition has been done by using two-dimensional finite element software Plaxis2D.

7. A Study on Contaminant Transport Through Soil

   Rajeshwari Puranik, Prasanna Patil

   Abstract

   Soil in ecosystem is contaminated by various environmental activities taking place in day-to-day life. Major contaminants in soil are chlorides, fluorides, nitrates, iron, silicates, etc. The present study deals with the transportation of contaminants like sodium chloride (Nacl) and sodium fluoride (NaF) in soil by advection–diffusion method. The tests are carried on soil mixed with varying percentages of sand from 10 to 40%. In the present study, the dosage of contaminants, i.e., Nacl and NaF, is varied from 0.1 N to 0.4 N, respectively. The column of size 60 cm is utilized, and up to 40 cm height, soil is compacted from the base. The solutions of additives are pumped at the rate of 0.208 ml/s. The time of flow at the entry and exit of soil column is observed, and solution is collected from the exit point to evaluate percentage absorption by the soil. For different normalities of sodium chloride such as 0.1 N, 0.2 N, 0.3 N, 0.4 N, corresponding relative concentrations obtained are 0.078, 0.073, 0.062, 0.056, and similarly, relative concentrations for sodium fluoride are also determined. The soil absorption capacity increases with increasing the concentration of contaminants. For all normalities of contaminants, the nature of results obtained follows the footprint of breakthrough curves. Strength parameter of contaminated soil is evaluated by unconfined compressive strength test. The strength of sodium chloride contaminated soil is increased irrespective of concentrations and decreased with increase in percentage addition of sand. The strength of sodium fluoride contaminated soil is decreased with longer curing period.

8. Effect of Induced Osmotic Suction and Bentonite Content on Swell Behaviour and Hydraulic Conductivity of Compacted Red Soil

   A. S. Devapriya, T. Thyagaraj

   Abstract

   Clay liners are integral part of both hazardous and municipal waste landfills that prevent leachate from percolating into the soil beneath and polluting it. Hence, the compacted soils must have very low hydraulic conductivity (<10^–7 cm/s) to act as effective clay liners. Locally available red soil may be used as a liner material as it satisfies the design criteria. To meet the hydraulic conductivity requirement, the locally available red soil was modified by adding 10% and 20% bentonite by dry weight. Multiple identical compacted specimens were set-up in oedometric assemblies under a surcharge pressure of 12.5 kPa and were inundated with distilled water, 0.4 M CaCl₂ and 0.4 M NaCl solutions to study the swelling behaviour of red soil and red soil modified with different bentonite contents. The specimens were compacted at their respective optimum moisture content values to their maximum dry unit weights. Falling head permeability tests were conducted to measure hydraulic conductivity using the rigid wall permeameters at a hydraulic gradient of 20 and surcharge pressure of 12.5 kPa. The nature of the inundating fluid and the bentonite content is seen to greatly affect the swelling behaviour and the hydraulic conductivity of the compacted red soil.

9. Use of Fly Ash as Weak Cementing Agent to Strengthen Marine Clay

   Sayali Belawadikar, D. S. Patil, Ashish Juneja

   Abstract

   Constructions on problematic soils are inevitable due to the increasing demand for land in the existing scenario. India has a coastline of 7500 km with large deposits of marine clay. Soft soils like marine clay are considered problematic due to its swelling behavior, low permeability, and highly compressibility. Landfill sites and reclamation areas formed due to dumping of dredged soft soils experiences high settlement and poor bearing capacity making it unsuitable as a foundation material. Atterberg limits represent the water holding capacity of soil. It can also contribute to estimation of shear strength, settlement, and permeability of soil. Researchers have explored various methods to reduce water holding capacity of marine clay and thereby enhance its engineering properties. Effective additives like fly ash, rice husk ash, marble dust, granite dust are widely mixed with marine soil to stabilize and improve its engineering behavior. Fly ash is a waste material produced in large amount at coal or lignite-based thermal power station. It requires large area of land for disposal as ash ponds as well as it causes air and water pollution. To address the adverse impact of dumping of fly ash on environment, wise utilization of fly ash is essential. In the present study, the effect of addition of Class F fly ash on liquid limit and plastic limit of marine clay and bentonite was studied. Marine clay obtained from Mumbai coast and bentonite from Kutch, Gujarat, was used in the tests. The liquid limit of the soil was determined using fall cone apparatus. Initially, the tests were performed on virgin clay only. Then the fly ash was added, and the percentage of fly ash in the soil was varied. The percentage of fly ash mixed in the soil ranges from 10 to 70%. The variation in liquid and plastic limit with the addition of fly ash was examined. It was observed that the plasticity index reduced by 60% in marine soil. Addition of fly ash reduced water absorption capacity of soil which in turn resulted in significant reduction in plasticity of soil. The usage of fly ash in improving clay with active minerals is novel and beneficial for reusing industrial waste products.

10. Physical and Swell Behaviour of Sand–Bentonite and Marble Dust–Bentonite Mixes

    Ankush Kumar Jain, Ayush Kumar, Arvind Kumar Jha

    Abstract

    Numerous researches have been carried out on bentonite amended with soils (commonly sand) to form barriers material for waste disposal projects such as landfill, cores of earth dams and radioactive waste repository systems. However, the development of sustainable geo-materials is still a greater concern for geotechnical engineer. Bulk utilization of marble dust, produced in the Rajasthan, is a serious concern for safe environment. In the present study, an attempt has been made to modify the behaviour of marble dust with bentonite to develop a novel liner material for landfill system. Further, the behaviour of marble dust amended with bentonite has been compared with sand–bentonite mixture which is known to be used as a liner material. Atterberg’s limits, free swell index (FSI) and compaction characteristics (i.e. optimum water content and maximum dry density) of various proportion of both sand–bentonite and marble dust–bentonite mixtures (0:100–100:0) were determined. It is observed that MDD and OWC of sand reduce and, increase with an increase in its substitution with bentonite, respectively. The similar tendencies have been observed for marble dust–bentonite mixes. Further, the FSI of sand and marble dust is also observed to be increased drastically with its substitution with bentonite. The physicochemical examinations (pH and electrical conductivity (EC)) of entire mixes have been performed to elucidate the mechanism.

11. Converting Agricultural Waste into Biochar for Improving Physical Properties of Soil

    M. P. Choudhary, H. D. Charan, Biswajit Acharya

    Abstract

    Biochar is a carbon-rich, fine-grained, porous material obtained from pyrolysis process, in which biomass is subjected to thermochemical conversion in the absence of either oxygen or very little oxygen. India is currently facing an acute problem of management of large quantities of agricultural waste which is either partially utilized or unutilized due to certain constraints. One of the indiscriminate uses of crop residues adopted by Indian farmers in the states of Punjab, Haryana and Uttar Pradesh is direct burning in open fields (in the form of Parali) which causes emission of greenhouse gases in the atmosphere. It is one of the sources of air pollution being faced every year during winter in the national capital region of Delhi. One of the recent advancements to combat this problem is the conversion of agricultural waste into biochar and applying it back into the soils to improve soil properties. Although biochar is not a new product, it has recently drawn attention of researchers because of its usefulness in improving the soil properties and as a means of carbon sequestration, thereby reducing greenhouse gas emission. Direct burning of agricultural wastes in fields cannot be called an environmental-friendly approach as it causes loss of biomass as well as introduces harmful gases into the environment. So converting agricultural wastes into biochar may be a better solution. In India, not much research has been carried out so far on biochar application in soils. The process of making biochar and the effects of utilizing biochar on the physical properties of soil have been presented in this paper, which will prove useful for Indian context where large quantities of agricultural waste are produced that creates environmental air pollution when directly burnt in fields.

12. Remediation of Cadmium-Contaminated Soil Using Biochar Derived from Wheat Straw, Rice Husk and Bagasse

    Aarushi Joshi, Dharmaraj J. Patil, Jagabandhu Dixit, Sailesh Narayan Behera

    Abstract

    Improper waste disposal has resulted in rapid deterioration of the environment and the advent of fatal diseases. Carcinogenic substances that percolate into the ground deteriorate the quality of groundwater and soil. Moreover, pollution from large-scale burning of agricultural waste each time after the harvest season makes the goal of a healthy environment of utmost importance. Toxins, such as polycyclic aromatic hydrocarbons (PAH) and heavy metal contaminants, have several pathways to enter into the environment and bio-accumulate within living organisms. The objective of this study is to synthesise a substance that will break the source-receptor pathway resulting in cleaner water and soil. Biochar, through ion exchange or physical adsorption, has the capacity to adsorb heavy metal ions such as those of cadmium. The biochar was synthesised from biomass consisting of wheat straw, rice husk and bagasse. The biomass was then heated to temperatures ranging from 300 to 700 °C using the process of slow pyrolysis, in an environment in which the oxygen supply was limited. The samples were then subjected to Fourier transform infrared spectroscopy (FTIR) to ascertain the functional groups present followed by powder X-ray diffraction (XRD) to determine the elements or form of metal oxides present in the samples. The samples were mixed with a known amount of cadmium solution, and the final testing was performed using atomic absorption spectroscopy (AAS). The final testing directly showed the heavy metal ion adsorption efficiencies of biochar derived from different types of biomass, giving an insight into the future scope of using biochar has a remediating agent

13. Influence of Lime on the Unconfined Compressive Strength of Cnoal Gangue

    Mohammed Ashfaq, M. Heera Lal, Arif Ali Baig Moghal

    Abstract

    Coal gangue is one of the largest industrial residues generated during the coal mining process. The surge in demand for coal has led to further increase in coal gangue production, and its safe disposal is an arduous effort in terms of costs involved and the associated environmental impacts. To address these issues, innovative methods are explored for coal gangue utilization in different fields. The bulk and effective utilization of coal gangue can be attained by using it for various geotechnical applications. Unconfined compressive strength (UCS) of any material plays a major role in its utilization for various geotechnical applications like reclamation fill, fill behind retaining wall, base and sub-base layer. In the present study, the UCS of coal gangue and its variation on addition of lime at different curing periods has been studied. The effect of lime content and curing period clearly manifested with a significant increase in UCS of stabilized coal gangue. The improvement in strength is attributed to the formation of pozzolanic compounds with the curing period.

14. Potential Application of Treated Bauxite Residue

    Sujeet Kumar, Abhay Kumar Verma, Arun Prasad

    Abstract

    Bauxite residue is a significant industrial solid waste residue produced by the Bayer process for the extraction of alumina from bauxite ores. It is usually disposed off in the form of slurry in the nearby areas of the alumina industry. About 400 million tons of bauxite residues are produced annually worldwide. However, it has some environmental and logistical problems in handling and disposal due to high alkalinity (pH 10–13.5), sodicity, fine particles, and some trace metal content. Thus, it cannot be used directly and requires pre-treatment before any civil engineering applications. In view of the given above, an attempt has been made to explore the potential of the bauxite residue for some civil engineering applications. The present study investigates the effect of various parameters on the strength and durability of bauxite residue. Further, a series of laboratory tests considering various parameters were carried out. The results indicate that treated bauxite residue with a certain combination of parameters (dry density, moisture content, and curing time) can be used as an unfired brick for low-cost housing.

15. Hydro-mechanical Behavior of Glass Fiber Reinforced Clay Barriers

    Koteswaraarao Jadda, Sharon Kumar Injamala, Ramakrishna Bag

    Abstract

    The current study highlighted the inclusion of glass fiber reinforcement on various hydro-mechanical properties such as volumetric shrinkage, suction, compressibility and hydraulic conductivity of the clay. The effect of electrolyte on the compressibility and hydraulic conductivity of the clay and reinforced clay soil was studied using two NaCl salt concentrations of 0.5 and 1.0 molarity (M). The results showed that increase in glass fiber content leads to increase in the total suction and hydraulic conductivity of clay marginally, whereas compression index was found to be decreased. For 1.0 M NaCl concentration, the compression index of the clay and reinforced clay soils was found to be decreased by about 31% and 19%, respectively. However, the hydraulic conductivity of the clay and reinforced clay was noted to be increased by about 35 and 9 times, respectively. Therefore, the glass fiber can be used as an effective reinforcement material for contaminated barrier materials to improve its properties.

16. Physical and Mechanical Behavior of Dredged Soil Acquired from Dal Lake—A Laboratory Study

    Rakshanda Showkat, B. A. Mir, K. M. N. Saquib Wani

    Abstract

    This study deals with the characterization of dredged material obtained by dredging the world famous Dal Lake in Shrinagar, UT of J&K. Due to the non-availability of suitable dumping sites for the wastes generated around Dal Lake and owing to the concern of environmental and health issues of these waste materials, geotechnical engineers have been under tremendous pressure from geoenvironmentalists for the characterization of the same. Therefore, in this study, an attempt has been made to characterize the waste material generated from Dal Lake by studying its various physical and mechanical properties. Dredged material has been collected from three different sites viz Nishat, Shalimar, Telbal located on catchment of Dal Lake to conduct various field and laboratory tests for the determination of field density, soil classification, compaction characteristics, strength parameters like unconfined compressive strength, direct shear test and California bearing ratio. On the basis of results, it was found that the dredged material mostly comprised of silt, clay, and sand and the strength parameters revealed that dredged material cannot be used as construction and foundation material in its in situ state. Therefore, suitable and feasible treatments should be provided to dredged materials  before being used for geotechnical applications.

17. Investigation of Sub-surface Contamination Around the Landfill Site: A Case Study

    Sagar Shinde, Arati Gaikwad, Swapnil Joshi

    Abstract

    Landfill leachate is a hazardous liquid that poses negative impacts if leaks out into environmental elements such as sub-surface soil and ground water systems. In the current study, detailed investigation was conducted on the municipal solid waste landfill site situated in northern part of Maharashtra, which is a non-engineered landfill. Ground water samples from nearby well and tube wells as well as soil samples around the landfill site were collected to assess the possible impact of leachate percolation on soil and ground water quality. Concentration of various physio-chemical parameters and heavy metals (Pb, Cd, Cr, Hg, As) in ground water was determined and compared with Indian Standard for drinking water. The soil samples were taken in the vicinity of landfill site at a shallow depth of 1 and 2 m using hand auger and were analyzed for presence of heavy metals and organic content. The contaminated soil near landfill was compared with normal soil samples taken at proximity of landfill site. The presence of high organic contents and heavy metals in soil samples indicates that there is appreciable contamination of soil due to leachate migration from landfill site. The result shows that there is a presence of contamination content in ground water table observed in surrounding wells. The study indicated that leachate can damage the soil and ground water properties and can cause greater threat to sub-surface environment if further action is not taken.

18. Geotechnical Characterization of Recycled Aggregates (RA) Comprising of Mixed Waste from Construction & Demolition (C&D) Plants

    Apoorva Agarwal, Manoj Datta, G. V. Ramana, N. K. Soni, Rajiv Satyakam

    Abstract

    India produces approximately 100 million tonnes of C&D waste per annum. Attempts are being made to separately process the C&D waste by segregating it from MSW stream. For this, C&D waste processing plants have been established in Delhi. About 1.15 million tons of C&D waste is annually processed in these plants. The bulk output from these plants is Recycled Concrete Aggregate (RCA) (10%), Recycled Aggregate (RA) (55%), and silt like fraction (below 0.075 mm) (35%). RCA and silt like fraction have reasonable demand in industry. RA comprising of mixed waste which has brickbats in highest proportion have low demand. It is coined as MRA (Mixed Recycled Aggregate) thereafter. Some areas in which gravel or sand-sized fraction of the MRA can be used are filters, drains, and backfill for embankments.

    The geotechnical characteristics of MRA from two C&D plants C&D P1 and C&D P2 were studied in laboratory for the sand-sized fraction. Grain size distribution, compaction, specific gravity, permeability, and shear strength test were done on MRA. The results have been compared with the locally available Badarpur Sand (BS). From the testing results it is observed that geotechnical properties like specific gravity, compaction, permeability, and shear strength of MRA are similar to BS. This study serves as a starting point for use of MRA to be used in various geotechnical application.