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The recent developments and application in the use of advanced composites in the improvement of soil are increasing on the basis of specific requirements and national needs. The need of efficient stabilization and strengthening techniques of existing soil has resulted in research and development of newer materials for improvement. Particularly for the black cotton soils which have high swelling and shrinkage tendencies, demands great deal of attention for stabilization. Modification of black cotton soils by admixtures is a common method for stabilizing the swell shrink tendency of expansive soils. Advantages of chemical stabilization are that they reduce the swell shrink tendency of the expansive soils and render the soils less plastic. As a further step towards the innovative materials to be used for the stabilization, this study endeavor to use waste material copper slag for the soil improvement. Copper slag, which is produced during production of copper from copper ore, contains minerals like iron, alumina, calcium oxide, silica, etc. For every tonne of metal production about 2.2 tonne of slag is generated. By using the admixture described above, Copper slag the index properties of soil has been improved. The various tests like Plasticity index, Standard Proctor and Swell index were performed and the result we got show much improvement. Soil has been collected from Umrakh region near SNPIT and RC College and the Admixture from SWIL JhagadiaCopper Limited , Gujarat. Priyank H. Patel | Ushma S. Thakor | Shaikh Heena H. "An Experimental Study on Stabilization of Expansive Soil using Admixture" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31006.pdf Paper Url :https://www.ijtsrd.com/engineering/civil-engineering/31006/an-experimental-study-on-stabilization-of-expansive-soil-using-admixture/priyank-h-patel

Damage to lightly loaded structures, paving and service piping in areas of expansive clay soils has occurred throughout the world. The cause of this damage has been the inability to accurately model expansive soil movement so that foundations are adequately designed to withstand the movement. The amount and rate of differential soil movement for expansive soils is due to a combination of soil characteristics, namely: suction compression index, unsaturated permeability, and diffusivity. Currently, geotechnical engineers run tests to measure the soil properties required to estimate differential soil movements. However, there seems to be apprehension toward attempting these soil movement calculations due to the perceived complexity of the calculations or a simple lack of understanding of the theory. The procedures delineating the step by step process used to calculate suction profiles and volume strains of expansive soils is presented. These procedures include the methodology to predict soil heave and shrink underneath shallow foundations which generate maximum center lift and maximum edge lift slab distortion modes. The main contributions of this research are: equations and procedures to calculate the equilibrium suction profile and depth to constant suction for a particular soil profile and location, equations to calculate the horizontal velocity flow of water in unsaturated soils, the methodology to predict differential soil movement shortly after a slab has been constructed and before the soil under the slab has reached an equilibrium moisture content, and the procedures to apply differential soil movement theory to soil profiles with multiple layers and moisture effect cases to be used for shallow foundation design

Prediction of the free swell index of the expansive soil using artificial neural network has been presented in this paper.  Input parameters for the artificial neural network model were plasticity index and shrinkage index, while the output was the free swell index. Artificial neural network algorithm used a back propagation model. Training of the artificial neural network model was conducted on the data collected from literature, and the weights and biases were obtained which described the relation among the input variables and the output free swell index. Further, the sensitivity analysis was performed, and the parameters affecting the free swell index of the expansive soil were identified. The sensitivity analysis results indicated that the plasticity index (63.97 %) followed by shrinkage index (36.03 %) was affecting the free swell index in this order. The study shows that the prediction accuracy of the free swell index of the expansive soil using artificial neural network model was quite good.

Expansive soils (ES) have a long history of being difficult to work with in geotechnical engineering. Numerous studies have examined how bagasse ash (BA) and lime affect the unconfined compressive strength (UCS) of ES. Due to the complexities of this composite material, determining the UCS of stabilized ES using traditional methods such as empirical approaches and experimental methods is challenging. The use of artificial neural networks (ANN) for forecasting the UCS of stabilized soil has, however, been the subject of a few studies. This paper presents the results of using rigorous modelling techniques like ANN and multi-variable regression model (MVR) to examine the UCS of BA and a blend of BA-lime (BA + lime) stabilized ES. Laboratory tests were conducted for all dosages of BA and BA-lime admixed ES. 79 samples of data were gathered with various combinations of the experimental variables prepared and used in the construction of ANN and MVR models. The input variables for two models are seven parameters: BA percentage, lime percentage, liquid limit (LL), plastic limit (PL), shrinkage limit (SL), maximum dry density (MDD), and optimum moisture content (OMC), with the output variable being 28-day UCS. The ANN model prediction performance was compared to that of the MVR model. The models were evaluated and contrasted on the training dataset (70% data) and the testing dataset (30% residual data) using the coefficient of determination (R 2 ), Mean Absolute Error (MAE), and Root Mean Square Error (RMSE) criteria. The findings indicate that the ANN model can predict the UCS of stabilized ES with high accuracy. The relevance of various input factors was estimated via sensitivity analysis utilizing various methodologies. For both the training and testing data sets, the proposed model has an elevated R 2  of 0.9999. It has a minimal MAE and RMSE value of 0.0042 and 0.0217 for training data and 0.0038 and 0.0104 for testing data. As a result, the generated model excels the MVR model in terms of UCS prediction.

Expansive soils are produced from the break down of basic igneous rocks where seasonal variation of weather is extreme. In India, these soils are normally derived from the weathering of basalt rocks. Also, these soil deposits are derived from various other types of rocks including very old sedimentary depositsin the present research, an attempt has been made to study the stabilization of the local soils high and low expansive having low bearing strength from two different parts of Bhopal by mixing independently with dolochar and fly ash plentily available in Bhopal in the proportions from 5 up to 30 by dry weight of the mixture with increment of 5 with and without lime The experimental programme conducted in this study is comprised of index tests, compaction tests, shear tests, unconfined compressive strength tests, CBR tests and consolidation tests in conformity with approved standards on soil alone and also on stabilised soils to evaluate their individual swelling, compaction, strength, compressibility and drainage characteristics. With addition of fly ash or dolochar, the L.L. and P.I. of soils gradually decreases with the increase of fly ash or dolochar contents. Maximum decrease is observed at 30 fly ash or 30 dolochar content Addition of fly ash or dolochar decreases the free swell index FSI of soil, maximum decrease being observed at fly ash or dolochar content of 30 . Addition of lime to the above mixtures, reduces FSI further. The FSI of soil 1 with 30 fly ash or dolochar content is reduced by 100 and 85 for soil fly ash and soil dolochar mixture respectively at 4 lime content. CBR of soil fly ash or soil dolochar increases with the increase of fly ash or dolochar content. The maximum increase being observed at 30 fly ash or dolochar content. At 30 fly ash content, the 4 days soaked CBR of soil 1 and soil 2 increase by 126 and 117 respectively, whereas, the 4 days soaked CBR of soil 1 and soil 2 at 30 dolochar content increase by 154 and 163 respectively. Sakshi Jaiswal | Prof. Nitesh Kushwah "An Experimental Study on Stabilization/Modification of Locally Available Expansive Soil using Industrial Wastes" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43834.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/43834/an-experimental-study-on-stabilizationmodification-of-locally-available-expansive-soil-using-industrial-wastes/sakshi-jaiswal

Thesis (M.S. in Civil Engineering)--Texas A & M University, Dec. 1997

Colorado Department of Transportation Research Report

This study delves into the efficacy of employing fly ash FA and sisal fibers SF as additives for soil stabilization, with a focus on the inherently fragile expansive soil found in the Sirsa, Haryana, region. Given the pressing need for stable soil in construction endeavors, the research examines both mechanical and chemical stabilization techniques. Through a series of experimental methods such as the California Bearing Ratio CBR test and Proctor compaction test, the study evaluates the impact of these additives on soil properties. Results reveal that the incorporation of FA leads to notable enhancements in both maximum dry density MDD and CBR value, whereas the introduction of SF, serving as a tensional reinforcement, decreases MDD while significantly augmenting CBR value, thus showcasing its potential for soil improvement. Sunil Kumar | Er. Raj Bala "Enhancing the Properties of Expansive Soil Stabilized with Sisal Fibre and Fly Ash" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-8 | Issue-3 , June 2024, URL: https://www.ijtsrd.com/papers/ijtsrd64928.pdf Paper Url: https://www.ijtsrd.com/engineering/civil-engineering/64928/enhancing-the-properties-of-expansive-soil-stabilized-with-sisal-fibre-and-fly-ash/sunil-kumar

This study presents the swelling parameters for expansive soil from Monywa Township, Saging Region. In various civil engineering projects, soil is used as a construction material and it supports structural foundation. Expansive clay soils swell when they are wetted and shrink when they are dried out. Volume changes of expansive soils can cause damages to structure resting on them. Therefore, it is essential to identify the existence of expansive soil at proposed construction site. The present study deals with the properties of expansive soils from Institute of Economic IE , Industrial Zone IZ and Hospital of Traditional Medicine HTM which are situated in Monywa Township, Sagaing Region. In order to identify and classify the expansive potential of expansive soils, performed tests on soils under study are Atterberg limit tests, Grain size analysis, Specific gravity test, Standard compaction test, Modified free swell index test and Consolidation test. Then, the expansive potential is qualitatively classified by various classification methods. In this study, swell potential and swell pressure are considered as the swell parameters. Empirical correlations for swell parameters of expansive soil from Monywa Township are proposed by using multiple linear regression analysis for three dimensional models based on free swell test results.  by Yee Win Shwe | Khin Myo Nwet "Proposition of Empirical Correlation Equation for Swell Parameters of Expansive Soil from Monwya Township"  Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-6 , October 2019,  URL: https://www.ijtsrd.com/papers/ijtsrd29384.pdf  Paper URL: https://www.ijtsrd.com/engineering/-/29384/proposition-of-empirical-correlation-equation-for-swell-parameters-of-expansive-soil-from-monwya-township/yee-win-shwe

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

Bhaskar Chittoori describes the universal issues caused by expansive soil and the research being conducted to find new solutions to combat it.

Bhaskar Chittoori describes the universal issues caused by expansive soil and the research being conducted to find new solutions to combat it.

Pavement engineers have long recognized the long term benefits of improving the strength and durability of pavement soil by mixing in a cementitious binder during reconstruction or new construction. In lieu of these, this research was carried out to study the effects of coconut waste ash CWA on lime stabilized lateritic soil for road construction. Natural lateritic soil was collected from a borrow pit nearer location Preliminary tests such as natural moisture content, specific gravity, particle size distribution and Atterberg limits were carried out on the soil for classification and identification purposes according to BS 1377 part 2 1990 . Strength tests such as compaction, California bearing ratio and unconfined bearing ratio were also carried out on the natural lateritic soil and stabilized soil according to BS 1924 1990 . The soil sample was mixed with lime in the proportions of 2, 4, 6, 8 and 10 , and were each subjected to Atterberg limits tests and strengths to determine the optimum quantity of lime for stabilizing soil. The plastic index varied from 13.93 – 9.33 and 23.64 – 14.46 for lime stabilized soils with optimum values obtained at 8 and 6 respectively. Plastic index decreased as the percentages of lime and CWA increased for CWA of ratio 1 1, 3 2 and 2 3 i.e. PI varied from 8.63 to 11.91 . Notable improvements were also observed in the MDD, UCS, OMC and CBR values of stabilized soil therefore coconut waste ash can be used to stabilize lateritic soil. Hence, the use coconut waste ash CWA should be encouraged in the construction industry to reduce the cost Akkim Sridhar Reddy | P. Hanuma "Effect of Alternative Materials on Properties of Expansive Soil for Construction of Road Subgrade by using Cocnut Husk Ash" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33469.pdf Paper Url: https://www.ijtsrd.com/engineering/civil-engineering/33469/effect-of-alternative-materials-on-properties-of-expansive-soil-for-construction-of-road-subgrade-by-using-cocnut-husk-ash/akkim-sridhar-reddy

"Originally released as Open-file report 78-9 SF."

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

Soil is very important in civil engineering constructions. The poor engineering properties of the local soils may present many difficulties for construction and therefore need to improve their engineering properties. Stabilization techniques can be used to improve the properties of soil. Soil stabilization improves various engineering properties e.g. bearing capacity, compressibility, strength, and various other properties of soil. In this study the impact of Marble Dust to improve the strength of soil.The effect of varying percentage of marble dust with sisal fiber on properties of Expansive Soil. Nilesh Madhukarrao Belorkar | Prof. Afzal Khan "Study on Stabilization of Expansive Soil by using Marble Dust with Sisal Fiber" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-4 , June 2022, URL: https://www.ijtsrd.com/papers/ijtsrd50161.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/50161/study-on-stabilization-of-expansive-soil-by-using-marble-dust-with-sisal-fiber/nilesh-madhukarrao-belorkar

In this research work, the relationship between suction and swelling potential and swelling pressure of an expansive soil with different chemical pore fluid qualities was investigated through experimental tests. Different soils were prepared with different chemical qualities of pore fluid (distilled water, sodium chloride, and calcium chloride solutions with concentration of 250 g/l). The samples were made by the static compaction method for testing. Soil-Water characteristic curves were determined by the filter paper method for each prepared soil sample. By performing the swelling tests, the amount of free swelling and swelling pressure for different water content were obtained for each sample with different pore fluid. By using the Soil-Water characteristic curve of each sample, the equivalent suction was obtained for each water content. Then the curve of variations of free swelling and swelling pressure versus suction were obtained for each pore fluid. The results showed that the pore fluid with different qualities causes different Soil-Water characteristic curves. On the other hand, comparing the results showed that, at a given suction the swelling potential and swelling pressure of the samples with NaCl solution as a pore fluid was more than the samples with the pore of distilled water or CaCl2 solution. In addition, the SEM results revealed that the soil structure is dependent on the used pore fluid quality. Also, for a specific pore fluid, the soil structure is not the same at the beginning and end of the test.

In the construction fields, the main characteristic required for the soil is their capacity to resist the super imposed loads safely by a control in stresses and deformations. Among the different types of soils, the construction activities on expansive soils requires adequate care since it was a fine grained soil that shows large volume change when exposed to varying water content.According to various studies, sub grade stabilization in roads can provide significant improvement in engineering properties. Microbial stabilisation is a new and alternative treatment method in geotechnical field by the use of bacteria in soil improvement, which are already naturally present in soils to develop more by providing the nutrients as an energy source. So far the researcher’s has been carried out with Microbial induced calcite precipitation MICP bacteria for the production of calcium precipitates by biological method and have practiced only on the sandy soils. These researches were done on the Experimental Study And Analysis Of The Effect OF Natural Microbial In Expansive Clayey Soil forming a cementious soil matrix.Totally 405 samples were prepared under varying bacterial concentrations of 106, 107 and 108 cfu ml, incubation periods of 1, 3, and 4 days with increasing curing periods of 1,7,14, 28 and 60 days. For each set of test 3 specimens were tested to evaluate the accurate value.For the volume changing nature of clay soil were analysed by conducting the Free Swell Index FSI tests. From the FSI test, the swell got decreased from 85 to 30 for Acetobacter treated soil. Similarly the free swell values are also decreased to 20 for soil treated with Acetobacter and 35 for the soil treated with E.coli at 60 day age curing, 108 cfu ml concentration and 4 day incubation period, as compared with untreated soil.The peak stresses for the 60 days curing period for Acetobacter, Bacillus and E.coli bacteria are410 kPa, 521 kPa and 341 kPa respectively. As the curing period increases the UCS value of Bacillus improved more than Acetobacter and E.coli at 60 day age and with 108 cfu ml concentration. The UCS strength of Bacillus bacteria treated soil was 4.5 times greater than the untreated soil strength when compared with Acetobacter and E.coli.For the CBR tests on treated soils, Acetobacter, Bacillus and E.coli were mixed with soil in varying concentrations ie, 106, 107 and 108cfu ml with incubation periods 1, 3, and 4 days and tested after curing the samples for 60 days to know the effect of long term treatment. California Bearing Ratio of soil increases to 6.7 , 8.2 and 5.9 respectively after 60 days curing from a value 2.3 with Acetobacter, Bacillus and E.coli and the concentrations of 108cfu ml and 4 day incubation period Rishav Sharma | Prof. Nitesh Kushwaha "Experimental Study and Analysis of the Effect of Natural Microbial in Expansive Clayey Soil" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd42332.pdf Paper URL: https://www.ijtsrd.comengineering/civil-engineering/42332/experimental-study-and-analysis-of-the-effect-of-natural-microbial-in-expansive-clayey-soil/rishav-sharma

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

Damage to lightly loaded structures, paving and service piping in areas of expansive clay soils has occurred throughout the world. The cause of this damage has been the inability to accurately model expansive soil movement so that foundations are adequately designed to withstand the movement. The amount and rate of differential soil movement for expansive soils is due to a combination of soil characteristics, namely: suction compression index, unsaturated permeability, and diffusivity. Currently, geotechnical engineers run tests to measure the soil properties required to estimate differential soil movements. However, there seems to be apprehension toward attempting these soil movement calculations due to the perceived complexity of the calculations or a simple lack of understanding of the theory. The procedures delineating the step by step process used to calculate suction profiles and volume strains of expansive soils is presented. These procedures include the methodology to predict soil heave and shrink underneath shallow foundations which generate maximum center lift and maximum edge lift slab distortion modes. The main contributions of this research are: equations and procedures to calculate the equilibrium suction profile and depth to constant suction for a particular soil profile and location, equations to calculate the horizontal velocity flow of water in unsaturated soils, the methodology to predict differential soil movement shortly after a slab has been constructed and before the soil under the slab has reached an equilibrium moisture content, and the procedures to apply differential soil movement theory to soil profiles with multiple layers and moisture effect cases to be used for shallow foundation design.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

Nitroaromatic-based compounds can pose a serious threat to ecosystems and human health. These compounds, which have been used in munitions and pesticides, are present in soil and groundwater at military installations and other sites. The presence of these contaminants in clayey soils poses a difficult and potentially costly remediation problem. The low hydraulic conductivity of these soils prohibits the use of conventional pump-and-treat remediation techniques, and high energy costs make the process of excavating and thermally treating the soil highly inefficient and damaging to the environment. For these reasons, much research has been done to advance the field of electrokinetic remediation as a viable cleanup technique. Although some studies have reported that organic molecules can be removed from clayey soils by electro-osmosis alone using a purging solution, the addition of amendments to the solution has increased removal efficiencies. The objective of this research was to advance the state of knowledge on a novel technique for cost-effective remediation of nitroaromatic compounds using cyclodextrin molecules as solubilizing agents and electrokinetically transporting them through the contaminated zone. The results provided direct evidence that it is possible to remove nitrobenzene and 2,4-DNT from expansive montmorillonite clay using electro-osmosis both with and without cyclodextrin amendments.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

Influence of soil suction, clay microstructure, and applied external loading upon the swelling behavior was undertaken to further the understanding of expansive soils. For the soil tested, the microstructure produced by kneading compaction did not change the particle orientation to any significant degree. Evaluation of the microstructure was performed with both X-ray diffraction and scanning electron microscopy techniques. The microstructure is perhaps best described by multi-grain or packet arrangements. A higher degree of packet dispersion occurred at molding water contents wet of optimum; however, it did not approach any high degree of preferred particle orientation. A swell test was developed using the Bishop Oedometer in which both soil suction and external loading could be controlled and measured. Using the axis of translation technique with a high air entry ceramic stone soil suctions of 5.1 kg/sq cm were measured. Results indicate that below a certain value of soil suction the swell will be accelerated with a further decrease in suction. As the applied loading is increased it will limit this acceleration and the soil suction-swell relationship becomes more linear with decreasing suctions.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.

Soil stabilization can be explained as the alteration of the soil properties by chemical or physical means in order to enhance the engineering quality of the soil. The process of soil stabilization helps to achieve the required properties in a soil needed for the construction work. Soil improvement could either be by modification or stabilization or both. Soil modification is the addition of a modifier (cement, lime etc.) to a soil to change its index properties, while soil stabilization is the treatment of soils to enable their strength and durability to be improved such that they become totally suitable for construction beyond their original classification. Expansive soils also known as swelling soils or shrink-swell soils are the terms applied to those soils, which have a tendency to swell and shrink with the variation in moisture content. As a result of which significant distress in the soil occurs, causing severe damage to the overlying structure. Soil possesses excellent performance at the optimum moisture content or below the optimum moisture content (dry side of optimum); however the strength and stiffness of soils reduces drastically as the moisture content increases beyond the optimum (wet side of optimum).This study is carried out with an intention to evaluate the effects of polypropylene fiber on the geotechnical properties of the locally available black cotton soil (Expansive soil) from Harihara city. Tests which are to be carried out on the sample of soil dealt with consistency limits, specific gravity, compaction, California bearing ratio, unconfined compressive strength and shear strength. These tests are to be conducted at both non-stabilized and stabilized states by adding 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3% of polypropylene fibre. The results show the effect of polypropylene fibre on geotechnical properties of the soil samples strength.

The rapid growth in population and industrialization cause generation of large quantities of effluents. The bulkeffluents generated from industrial activities are discharged either treated or untreated over the soil leading to changes in soil properties causing improvement or degradation of engineering behaviour of soil. If there is an improvement in engineering behaviour of soil, there is a value addition to the industrial wastes serving thethree benefits of safe disposal of effluent, using as a stabilizer and return of income on it. If there is degradationof engineering behaviour of soil then solution for decontamination is to be obtained. Hence an attempt is madein this investigation to study the effect of Textile effluent on the Differential free swell index Value of an expansive soil. 

Abstract — An expansive soil is any soil that is prone to large volume changes (shrinking and swelling) directly related to changing moisture conditions.   The swelling capacity can cause heaving , or lifting of structures whilst shrinkage can cause differential settlement.   The amounts by which the ground can shrink and/ or swell depend not only on the supply of moisture in the ground but also on the type and amount of clay minerals, internal structure and void ratios of the soil. Characterization of swelling potential is critically important to mitigate the adverse effects of expansive soils. Therefore, t his study uses the coefficient of linear extensibility (COLE) as the controlling method to characterize swelling potential of expansive soils . The samples for this test were retrieved from two different locations in areas prone with expansive soils in Kibaha Township in Tanzania. Bulk density was determined on irregular soil clods and COLE was calculated as the difference between bulk density values at 1/3 bar and oven-dry condition . The coefficient of linear extensibility that ranged from 0.09 to 1.15 clearly indicated soils with high to very high shrink–swell potential . Lastly, a direct relationship existed between COLE and colloids contents with high degree of correlation (i.e. Correlation Coefficients   (R) equal to 0.942 and 0.824 for samples RC5 and RB3 respectively) providing a confirmation to the presence of high to very high expansive potential of the soils.

This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.