Soil Problems Research Articles

An experimental study on evaluation of fiber Reinforced-Fly ash stabilized black cotton soil as a sustainable subgrade material

With population escalation and the reduction in availability of land, there is a growing demand for structures on weak or soft soils. Black cotton (BC) soil has been considered as a problematic soil because of high swelling potential. Pavements constructed on BC soil subgrade suffer from severe rutting and cracking on the pavement surface. With a focus on avoiding this type of failure in the BC soil, stabilization with reinforcement is preferred recently. The aim of the current work is to check the efficiency of Poly Vinyl Chloride (PVC) fiber reinforced-fly ash stabilized black cotton soil as a sustainable subgrade material. PVC fiber as reinforcing material and Fly ash as the admixture for stabilizing the BC soil is used. For minimizing the impact of fly ash on environment, use of waste products in construction work is inevitable and a sustainable solution.In the current research work, Black cotton soil from three different places of Odisha have been collected and treated with different percentage of fly ash and PVC fiber so as to improve different properties of soil. From the results it is found that there is an increase in Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) values of the treated soil and the optimum value of fly ash is found to be 30% and PVC fiber to be 1.5%.

Reducing Settlement and Collapse of Gypseous Soil Using Geotextile Reinforcement

Collapsible soils are problematic soils that have substantial strength while dry but lose strength when wet, resulting in excessive settlements. Soil collapse occurs when increasing moisture weakens chemical or physical connections between soil particles, allowing the soil structure to collapse. The existence of these soils, often with significant gypsum concentration, created serious challenges for structures and major projects. The primary goal of this study is to conduct a series of model tests subjected to static vertical stress to assess the ability of soil stabilization using geosynthetics material by employing single, double, and triple geotextile layers put at various places. A unique model test configuration was employed for this testing. The gypseous soil used was brought from near Sawa Lake by coordinates (31◦18′42.83″N, 45◦00′49.36″E) in Al-Muthanna Governorate. The gypsum content was more than (37%). It was found that, the ultimate bearing capacity of dry and wet gypseous soil models had been determined by using Two Tangent Intersection technique. The results show the Settlement Reduction Factor (SRF) % and the ratio of decreasing the collapse magnitude (Δed )

Effect of voids in kaolin stabilised by ground granulated blast furnaces slag mixtures

Kaolin is known as problematic soil which has a low strength that needs to improve before construction. Chemical stabilization with cement is used widely to stabilize different clay types; however, using it comes with disadvantages associated with carbon dioxide emission and sustainability issues. As an alternative to cement, Ground Granulated Furnaces Blast Slag (GGBS) has been applied to stabilise kaolin. The increment in the strength is due to the formation of new products that fill the soil voids. The formation of those new products is verified using Field Emission Scanning Electron Microscopy (FESEM). However, the changes in pore space cannot be quantified using FESEM. Thus, this study uses Image J to calculate voids area detected by (FESEM) for different kaolin-GGBS mixtures with different content of GGBS cured for different curing period. The book-like structure for the raw kaolin have changed slightly when mixed with GGBS. This is due to the formation of hydrate gels as a result of the pozzolanic reaction. The results from image J indicates that the void decreases as the content of GGBS increases as well as the curing period.

Assessing the compaction characteristics of modified soil with Incinerated municipal solid waste

The generation of municipal solid waste is increasing day by day with a rise in population. The improper disposal of waste releases methane which is more responsible for global warming and also it affects the health condition of the surrounding people. It is the need of the hour to identify the effective use of municipal solid waste into by-products or as a replacement material in civil engineering field. In this current work, an attempt is made to assess its effective use. The compaction characteristic of the problematic soil is modified with the inert form of municipal solid waste in stabilizing the soil. From the result, the percentage of the inert material helps with the reduction in dry unit weight and increase in its corresponding moisture content of the soil. This trend is identical to that of any of the inert materials from the industry. Hence it is observed that this material can be utilized in road construction and helps in improving the environment by reducing the quantity of waste disposed in the open dumpsite.

An integrated approach on extraction methodologies of nanosilica from cultivated agricultural wastes and microstructural characteristics – A review

In the present scenario, the significant environmental pollutants are from the cultivated agricultural waste by incineration process; in the process, more contaminants directly enter into the atmosphere. Therefore, the utilization of these wastes has been proved to be a better helpful product in geotechnical engineering applications. The primary product extracted from cultivated agricultural waste is nanosilica. It can be used as a supplement for stabilizing soft soils and improving the mechanical properties of problematic soils, polymer composites, pest control, biomedical applications, and increased concrete strength with durability properties. This paper deals with previous studies on the extraction of nanosilica from cultivated agricultural wastes with different methodologies such as precipitation, surface modification, calcination, and warm’s digestive process and characterized by microstructural analysis. Out of many available methodologies, precipitation has been proved to be an effective way to extract of nanosilica percentage, less consumption time, double reflexed, and economy. On the other hand, various studies on microstructural analysis proved that more silica, nanosized, amphorous form, and more symmetrical bonds between Si and O.

Review of classification methods to determine expansion degree of expansive soils in Indonesia

Expansive soils are one of the problematic soils that can cause damage to structures, such as buildings and roads. In Indonesia, the geographical distribution of expansive soils is quite widespread, in many regions including Java, Sumatera, and Papua. This study was conducted by reviewing previous research on the expansion degree of expansive soils. The suitability of the expansion degree indicated by the activity method, Van der Merwe’s criteria, and Chen’s criteria were evaluated by comparing a series of laboratory test results to these criteria. It was observed that the expansion degree indicated by these criteria did not necessarily reflect the actual swelling potential. Other indicators, other than typical index properties, are needed to predict the expansion degree more accurately.

Evaluation of Dhaincha Genotypes Based on Seedling Biomass Yield

To improve the fertility of the soil, several green manure crops are being cultivated. Dhaincha, is an ideal green manure crop used for the improvement of soil fertility and it also reclaims problematic soils. To screen out the Dhaincha genotypes based on the seedling biomass, a pot culture experiment was carried out at the Department of Plant Breeding and Genetics, Anbil Dharmalingam Agricultural College and Research Institute, Tiruchirappalli, with four different genotypes namely Vellore local, Villupuram local, Sivagangai local and Pant dhaincha. Root length, shoot length, fresh and dry weight of root & shoot, base diameter, and biomass per plant were recorded at ten day of intervals till sixty days after sowing. All the parameters showed significant variation and increased steadily every ten days after sowing. Sivagangai local recorded the highest growth parameters than the other genotypes. The highest biomass yield was observed in Villupuram local (0.029 g/plant) at 10 DAS, indicating that it produces more biomass during the early stages of growth. At 60 DAS, Vellore local recorded a high total biomass yield (2.3 g/plant), followed by Villupuram local (1.2 g/plant), Sivagangai local (1.08 g/ plant), and Pant dhaincha (0.9 g/ plant). Based on the growth parameters and High biomass yield per plant Sivagangai local and Vellore local can be selected for further crossing programmes.

Future Perspective of Seed Ball Technology For Creating New Ecosystem

Seed balls as a low-cost technology is unique, scattered in a controlled manner, and give life to new plants from vegetation deficient area, deforestation area, desert area, grassland area, agriculture and horticulture cultivable land area throughout the world. Seed balls became an important aspect of natural farming and conservation enterprises all over the world. This scheme in view of different funding given to government and private sectors is for improving ecosystems and getting a healthy environment with low-cost seed ball technology. Seed ball technology is useful for foundation of woods or remain of trees in a space where there was no past tree cover. Using seed ball technology many agricultural and horticultural crops may be grown in problematic soil without land preparation such as the plowing, weeding, and irrigation and protect from birds, ants, and unfavorable stress (abiotic and biotic).

A study on soil stabilization for some tropical soils

Stabilization of problematic soils for civil engineering applications to achieve the needed soil engineering properties while considering cost and environmental impacts is essential. Soil stabilization can be done physically or chemically, and in many times, it imperatively become a basic advance for making construction. Several chemical additives, with lime, cement, or fly ash are typically used for this objective. For arid and semi -arid regions in developing countries where acute shortage of such construction materials and height cost of chemical additive like cement, instead cheaper alternative stabilizer could be used. An experimental based investigation was carried out to study and assess the effectiveness of a low-cost alternative stabilizer, namely the use of lime for stabilizing cohesive soils and mechanical compaction for cohesionless soils and their effects on the geotechnical properties of stabilized tropical soil. Five soil samples from each type of soil were collected from Khartoum, which are representing wide range of tropical soils available in arid regions. Cohesive soils were mixed with different amounts of lime, varying from 0, 5, 7, 9, and 11% by dry weight of soil whereas mechanical compaction was done for cohesionless soils. Laboratory tests such as consistency test, compaction, and California Bearing Ratio test (CBR) were performed to measure the engineering characteristics of the stabilized soils. The result showed that with the supplement of various proportions of lime, both the liquid limit and plasticity index values reduce as the concentration lime is increased, and the plastic limit of the cohesive soil exhibit an increasing trend and the optimum moisture content, whereas the maximum dry density decreased. The stabilized soil strength is observed to be increasing with the increase of lime content, the heigh values of CBR which is attributed to the lesser voids in the admixture soils with low plasticity and dry unit weight.

Determination of Unconfined Compressive Strength and Atterberg Limit of Soft Clay by Stabilizing with Sodium Silicate and Biomass Silica in Batu Pahat

Soft clay soils can be considered as problematic soil with the characteristic of high compressibility, low permeability and low shear strength. Construction on soft clay deposit may causes problem such as insufficient bearing capacity, settlement problem and instability on excavation and embankment. Ground improvement methods were used as the aimed of this study is to determine the effect of non-traditional stabilizer on the compressive strength of soft clay soils. Therefore, the objective of this study is to determine effect of compressive strength of untreated and treated soft clay soil with addition of non-traditional stabilizer at different curing periods. The soil properties of soft clay soil such as compaction, Atterberg limits, and unconfined compression strength (UCS) testing methods were used to observe the performance of treated and untreated samples. The test results from the UCS indicated that once Biomass Silica and Sodium Silicate in the form of SH-85 and TX-85 have been added to the clay soil, the strength of the sample will increase with increasing percent of sodium silicate and curing periods.

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

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

Assessment Of Factors Affecting Road Pavement Design And Remedial Actions

Many factors such as number of vehicles, speed, climatic conditions and other factors affect are to be considered for the design of pavement. In this article we will discuss about the factors influencing pavement design. Pavements are engineered structures which are used as roads, runways, parking areas, etc. Ground or surface transportation is the most widely used transportation in the world. So, construction of pavements should be done as it is strong and durable for their design life. There are so many factors which influencing the pavement design. The factors may be of loading, environment, materials used etc. Which are as follows Wheel load, Axle configuration, Contact pressure, Vehicle speed, Repetition of loads, Subgrade type, Temperature and Precipitation. This paper aims to present a review on the performance, problems and possible remedial measures practices for roads constructed on these problematic soils in the country. Finally, emphasis should be given to the importance in construction in this kind of soil of strictly applying engineered design of geometric, drainage, pavement thickness, material selection and proportioning. Thus, those concerned bodies shall decide to accept and control the risk associated with construction on this soil or not, or to decide that more detail study is required to allow for extra design and construction preemptive measures once the potential problem has been identified and the end user convinced of the cost-savings in adopting a pro-active approach.

Performance of electrokinetic treatment of fine-grained problematic soils

Electrokinetic (EK) treatment is an innovative, cost-effective in situ ground modification technology. The EK treatment uses a combination of low-voltage direct-current, electrodes, and ionic solutions across problematic soil to improve the ground conditions. This study aims to model the effect of changing electrode length (le) on the performance of the EK treatment on the engineering properties of fine-grained problematic soils. The consideration of the changing electrode lengths (le), varying soil depths (ds), and lengthwise anode to cathode distances (dA↔E), in the soil block samples, is in the form of the laboratory model test tank. The significant performance of the experimental tests was with changing electrode lengths of 0.25le (7.5 cm), 0.50le (15.0 cm), 0.75le (22.5 cm), and 1.0le (30.0 cm). The study analyzed the test data obtained from the Atterberg limit and one-dimensional swelling tests at different extraction points of the EK treated soils in the test tanks. Furthermore, the study carefully analyzed the effect of changing electrode length (le) on the performance of the EK treatment. The results of the Design of Experiment (DOE) model analysis revealed that the effect of changing electrode length (le) on the plasticity index (PI), and swelling potential (SP) of the EK treated soils, was significant. For a specific soil depth (ds), the electrode lengths (le) of 0.50le and 0.75le were significantly effective in reducing the PI, and the SP of the EK treated soils. Unlike other studies in the literature, the use of DOE analysis in the present study enabled the detection of the significant input factors and their interactive effects on the PI and the SP, thus, enabling the practicing engineers to navigate accurate design models for large in situ applications.

Effect of Nanosilica on the Macro- and Microbehavior of Dispersive Clays

AbstractDispersive clays are one of the common problematic soils owing to their unstable structure, which causes numerous geotechnical problems in construction projects. One of the main strategies ...

Sustainable ground improvement method using encapsulated polypropylene (PP) column reinforcement

This study investigates the effectiveness of encapsulated polypropylene (PP) column in enhancing the undrained shear strength of kaolin (soft clay). The usage of PP in treating problematic soil is a more sustainable and cost-effective alternative compared to other materials. The installation of granular column can be done by using vibro-replacement method. Several geotechnical tests to determine the properties of materials were conducted. The shear strength of treated kaolin sample was examined by using Unconfined Compression Test (UCT). There are seven (7) batches of soil sample in total which included a control sample, three (3) batches of 14 mm and three (3) batches of 20 mm diameter PP column. Different diameters of PP column were examined with 60 mm, 80 mm and 100 mm height, respectively with soil sample of 50 mm in diameter and 100 mm in height. The shear strength improvement of kaolin is 33.82%, 46.51%, and 49.88% when implanted with a PP column with a 7.84 area replacement ratio and 0.6, 0.8 and 1.0 penetration ratio. The soft soil treated using 16.00 area replacement ratio with 0.6, 0.8 and 1.0 penetration ratio has a shear strength increment of 25.22%, 33.39% and 37.59% respectively. In short, the shear strength improvement of the kaolin clay depends on the parameter of the PP column used to reinforce the sample.

The Implementation of Industrial Byproduct in Malaysian Peat Improvement: A Sustainable Soil Stabilization Approach

Peat is a well-known problematic soil associated with poor engineering properties. Its replacement with an expensive competent foundation material is practiced for road embankment construction which is costly and causes greenhouse gas emissions. Therefore, this paper investigated the effectiveness of a byproduct from a metal industry (silica fume) to stabilize peat along with ordinary Portland cement (OPC) through a series of experimental tests. After peat-indexed characterization, a number of standard compaction and mechanical tests were performed on the stabilized and parent peat. For this purpose, nine designated mixes were prepared possessing various combinations of silica fume (SF) and 10–20% OPC. Unconfined compressive strength (UCS) and California Bearing Ratio (CBR) tests were carried out after 7, 14, and 28 days of curing to assess strength enhancement and binder effectiveness, and the microstructural evolution induced by the binders was examined with scanning electron microscopy (SEM). The analysis revealed a substantial improvement in mechanical properties with the incorporation of SF and OPC, ultimately meeting the minimum strength requirement for highway construction (i.e., 345 kPa). A peak UCS of 1063.94 kPa was recorded at 20% SF, and an unsoaked CBR value of 42.95 was observed using 15% SF and 15% OPC after 28 days of curing. Furthermore, the increasing percentage of hydraulic binders exhibited brittle, collapsible failure, while the microstructural study revealed the formation of a dense matrix with a refined pore structure in the treated peat. Finally, a significant statistical analysis was carried out by correlating the test parameters. In this way, rather than stockpiling and dumping, an industrial byproduct was implemented in peat stabilization in an eco-friendly manner.

Geopolymers as Alternative Sustainable Binders for Stabilisation of Clays—A Review

The need to transit to greener options in soil stabilisation has revamped research on the use of industrial and agricultural by-products in order to cut down on the current carbon footprint from the use of ordinary Portland cement (OPC) and lime related binders for the treatment of problematic soils. This study is a review on the use of geopolymers constituted by alkali activation of several industrial wastes such as pulverised fuel ash (PFA), ground granulated blast furnace slag (GGBS), metakaolin (MK), glass powder (GP), palm oil fuel ash (POFA), silica fume (SF), rice husk ash (RHA), volcanic ash (VA), and marble powder (MP) for the stabilisation of weak clays. The performance of stabilised clays as subgrade and subbase materials for road pavement construction was evaluated by comparing the 7 day UCS of the treated clays with the strength requirement for stabilised materials as outlined in BS EN 16907-4. The result of the study shows that geopolymers can be employed in improving the engineering properties of problematic clays to meet practical applications. Strength improvement was observed in the stabilised clays with increased precursor content, molarity of alkaline activator, and curing period.

Waste combustion and lime induced calcite precipitation for problematic soils stabilization; an applied review

The precipitation of calcite for sustainable modification of expansive soils for green and sustainable construction has been a subject of serious energy investigation in the past years. This is due to the promise for an eco-friendly construction materials synthesis and efficient soil stabilization and earthworks. Results of previous studies have shown remarkable achievement in this field in recent years. These range between treated soils swelling potential mitigation, shrinkage and crack remediation and strength characteristics improvement. It is very important to note that these results were achieved by deploying the activities of different species of bacteria in a mechanism known as microbial induced calcite precipitation (MICP). However, the affinity between lime (CaO) and CO2 emission; released during the direct and controlled combustion of solid waste in the derivation of ash is proposed in this review work. It is proposed to precipitate calcite in another mechanism and setup known as “lime induced calcite precipitation” (LICP). In order words, this is a complete energy cycle of emission entrapment and sustainable generation of construction materials (ash). This review has proposed that calcite can be precipitated without going through the rigors of securing bacteria and adopting the hydrolysis processes. Generally, this simple setup proposed in this review work serves the same energy purpose of inducing the precipitation of calcite as a construction geomaterial.

Evaluating Biosedimentation for Strength Improvement in Acidic Soil

Marine clay soils are problematic soils in the construction industry when they are subjected to construction loads. When these soils are loaded, they lose their structure. This leads to the soil being unable to withstand loads of any magnitude without exhibiting significant, permanent deformations. In order to stabilize the marine soil, new methods for soil improvement were built upon biogrouting by incorporating physical, biological and chemical treatments into the soil. However, the biggest challenge of this method is the bacteria migration through the soil medium. To overcome this issue, the electrokinetic phenomenon can be utilized alongside biogrouting to prevent the bacteria migration. In this regard, the present study applied electrobiogrouting stabilization to investigate the improvement of acidic marine clay soil with a pH of 3.69. To accomplish this, two large-scale physical models with dimensions of 500 × 300 × 1200 mm were fabricated to examine the influence of two different treated distances between the inlet and outlet—450 mm (D45) and 600 mm (D60)—on the stability of the treated soil. It was observed that the shear strength of the treated soil improved significantly. The shear strength at the D45 treated distance increased from 3.65 kPa (untreated soil) to 28.14 kPa (treated soil). However, the strength increased by increasing the treated distance. In addition, compressibility and soil electrical conductivity were reduced significantly, and the Atterberg limits were significantly enhanced from OH to OL. The reasons for the enhancement of treated soil were the formation of CaCO3, which filled the soil voids, and that the water content was reduced. To address issues with marine clay soil, this study aims to minimize the high cost of a special foundation system and the use of non-environmentally friendly materials such as calcium-based binders, aside from the reduction of deformations caused by loading. The findings of this study can be used for acidic soils and the improvement of soil’s geotechnical behavior in general.

Global climate change and the creation of adapted varieties of forage crops

In Russian agriculture, fodder crops play a huge role as a source of complete feed for animals and as the main factor in the greening of all agriculture. It is fodder crops that are the main factors for increasing the humus content in soils, as the main indicator of their fertility, it is they who can most successfully fight wind and water erosion, it is they who most successfully of all agricultural crops can grow on the poorest and most problematic soils (saline, arid, waterlogged, etc.) being pioneers for the cultivation of basic food crops. This predetermines the primary role of forage crops in responding to climate change throughout Eurasia. In the past periods of history, global climate change led to major social shocks precisely because of a sharp decline in agricultural production, crop failures, and even a subsequent decline in population in individual countries [1]. Timely response to such changes by creating varieties adapted to new limiting environmental factors will not only successfully overcome the expected crisis, but also benefit from such a change. In addition to using traditional methods, great hopes are pinned on the widespread use of modern genetic technologies, biochemical and physiological methods, methods of cell and tissue culture.