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Craig H Benson - One of the best experts on this subject based on the ideXlab platform.
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deer track bioreactor experiment field scale evaluation of municipal solid waste bioreactor performance
Journal of Geotechnical and Geoenvironmental Engineering, 2012Co-Authors: Christopher A. Bareither, Craig H Benson, Morton A Barlaz, Ronald J Breitmeyer, Tuncer B. EdilAbstract:AbstractThe Deer Track Bioreactor Experiment (DTBE) was a field-scale experiment conducted in a drainage lysimeter (8.2-m height, 2.4-m diameter) to assess the physical, chemical, and biological response of municipal solid waste with leachate addition. The experiment was operated for 1,067 days, with leachate dosing initiated on Day 399. Fresh leachate collected from a full-scale landfill was used for each dose. The ratio of cumulative leachate effluent to influent volume increased during dosing and leveled off at approximately 80%, indicating field capacity was achieved. Peak Darcy flux ranged from 2×10-7 m/s to 4×10-5 m/s, with larger flux computed for the last four doses when waste saturation was higher. During the experiment, the average Dry Unit Weight of the waste increased 28% and the Dry-Weight water content (wd) increased 18%; field capacity of the waste was 44 to 48% on a Dry-Weight basis. Biochemical methane potential decreased from 51.4 to 3.4 mL-CH4/g-Dry, indicating that 93% of the potent...
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effect of suction on resilient modulus of compacted fine grained subgrade soils
Transportation Research Record, 2009Co-Authors: Auckpath Sawangsuriya, Tuncer B. Edil, Craig H BensonAbstract:Resilient modulus of compacted subgrade soils is the primary mechanical property required in the mechanistic-empirical design of pavement structures. In most cases, the resilient modulus is determined of a specimen prepared at a single compaction condition (i.e., near optimum water content and at a specified percentage of maximum Dry Unit Weight). However, in the field, the resilient modulus changes in response to changes in moisture content and corresponding changes in matric suction. The relationship between resilient modulus and suction is described for four fine-grained compacted subgrade soils. Resilient modulus tests were conducted in accordance with NCHRP 1-28A on test specimens prepared from each soil and conditioned to different matric suctions. The summary resilient modulus increases with increasing matric suction. This relationship is quantified empirically by using a modulus ratio, defined as the ratio of the summary resilient modulus at a particular suction to a reference summary resilient mo...
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estimating optimum water content and maximum Dry Unit Weight for compacted clays
Journal of Geotechnical and Geoenvironmental Engineering, 2000Co-Authors: Lisa R Blotz, Craig H Benson, Gordon P BoutwellAbstract:An empirical method is described for estimating maximum Dry Unit Weight (γdmax) and optimum water content (wopt) of clayey soils at any rational compactive effort E. One variation of the method uses the liquid limit (LL) and one compaction curve, whereas the other uses only the LL. Linear relationships between γdmax and the logarithm of compaction energy (log E), and wopt and log E, both of which are a function of the LL, are used to extrapolate to different compactive energies. Data for 22 clayey soils were used to develop the method, and data for five additional soils were used for validation. Both variations of the method are unbiased and robust. The variation employing the LL and one compaction curve is slightly more precise, with typical errors of about ±1% for wopt and ±2% on γdmax. For the variation employing only the LL, typical errors are about ±2% for wopt and ±6% on γdmax.
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estimating optimum water content and maximum Dry Unit Weight for compacted clays technical note
Journal of Geotechnical and Geoenvironmental Engineering, 1998Co-Authors: Lisa R Blotz, Craig H Benson, Gordon P BoutwellAbstract:An empirical method is described for estimating maximum Dry Unit Weight and optimum water content of clayey soils at any rational compactive effort E. One variation of the method uses the liquid limit (LL) and one compaction curve, whereas the other uses only the LL. Linear relationships between the maximum Dry Unit Weight and the logarithm of compaction energy (log E), and the optimum water content and log E, both of which are a function of the LL, are used to extrapolate to different compactive energies. Data for 22 clayey soils were used to develop the method, and data for five additional soils were used for validation. Both variations of the method are unbiased and robust. The variation employing the LL and one compaction curve is slightly more precise, with typical errors of approximately plus or minus 1% for optimum water content and plus or minus 2% on maximum Dry Unit Weight. For the variation employing only the LL, typical errors are approximately plus or minus 2% for optimum water content and plus or minus 6% on maximum Dry Unit Weight.
Donald D. Carpenter - One of the best experts on this subject based on the ideXlab platform.
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an investigation on erodibility and geotechnical characteristics of fine grained fluvial soils from lower michigan
Geotechnical and Geological Engineering, 2012Co-Authors: Matthew A Mcclerren, Hiroshan Hettiarachchi, Donald D. CarpenterAbstract:Scour and erosion potential of a soil are closely related to each other. Similarities or differences between them have not been defined fully and the terms are often used interchangeably or in association with one another. Erodibility is a property of soil that describes erosion potential. Therefore, a proper understanding of erodibility should help predict scour more accurately. In the past, researchers have looked into erosion of soils with the ultimate objective of understanding the erodibility with respect to the standard geotechnical properties. Most research has shown the difficulties associated with correlating erodibility to any one or more soil properties. The research described in this paper is mainly focused on the relationship between erodibility and Dry Unit Weight of soil with varying fractions of fines. Soils tested using laboratory Jet Erosion Test (JET) indicated that the logarithm of erodibility makes a linear inverse relationship with the Dry Unit Weight. In situ JETs confirmed the range of erodibilities established by the laboratory JETs. The best correlations between erodibility and Dry Unit Weight appeared within a single category of soil as classified by the Unified Soil Classification System. In addition, it was also determined that the logarithm of erodibility is inversely related to the angle of internal friction of the fluvial soils tested during this investigation.
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an investigation on erodibility and geotechnical characteristics of fine grained fluvial soils from lower michigan
Geotechnical and Geological Engineering, 2012Co-Authors: Matthew A Mcclerren, Hiroshan Hettiarachchi, Donald D. CarpenterAbstract:Scour and erosion potential of a soil are closely related to each other. Similarities or differences between them have not been defined fully and the terms are often used interchangeably or in association with one another. Erodibility is a property of soil that describes erosion potential. Therefore, a proper understanding of erodibility should help predict scour more accurately. In the past, researchers have looked into erosion of soils with the ultimate objective of understanding the erodibility with respect to the standard geotechnical properties. Most research has shown the difficulties associated with correlating erodibility to any one or more soil properties. The research described in this paper is mainly focused on the relationship between erodibility and Dry Unit Weight of soil with varying fractions of fines. Soils tested using laboratory Jet Erosion Test (JET) indicated that the logarithm of erodibility makes a linear inverse relationship with the Dry Unit Weight. In situ JETs confirmed the range of erodibilities established by the laboratory JETs. The best correlations between erodibility and Dry Unit Weight appeared within a single category of soil as classified by the Unified Soil Classification System. In addition, it was also determined that the logarithm of erodibility is inversely related to the angle of internal friction of the fluvial soils tested during this investigation.
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laboratory and field investigation on variation of erodibility with Dry Unit Weight of different soils
Proceedings of GeoFlorida 2010: advances in analysis modeling and design West Palm Beach Florida USA 20-24 February 2010., 2010Co-Authors: Matthew A Mcclerren, Hiroshan Hettiarachchi, Donald D. CarpenterAbstract:Better understanding the erodibility of a given type of soil can help predict scour at bridge piers more accurately. In the past, researchers have looked into erosion of soils with the ultimate objective of understanding the erodibility with respect to the other geotechnical properties. Most research has shown the difficulties associated with correlating erodibility to any one soil property. The research described in this paper is about an investigation on erodibility and Dry Unit Weight of soil with varying fractions of fines. Soils tested using laboratory Jet Erosion Test (JET) indicated that the logarithm of erodibility makes a linear inverse relationship with the Dry Unit Weight. In situ JETs confirmed the range of erodibilities established by the laboratory JETs. The best correlations between erodibility and Dry Unit Weight appeared within a single category of soil as classified by the Unified Soil Classification System. Background Two of the most common causes of bridge failure in the United States are flooding and scour accounting for 165 and 78 cases of bridge failure respectively between 1989-2000, which represents over 47% of all bridge failures that occurred. In addition, the failures caused by flooding are also believed to be related to scour (Wardhana and Hadipriono 2003). As such, accurate estimation of bridge scour is essential to protect lives and property while preventing over designing piers that can be costly. Scour prediction relies on empirical or semi-empirical equations, as a means to predict scour but most equations are applied over a range of soil conditions from clean sand to clay without consideration for soil variability. Scour is the erosion of streambed or bank material due to flowing water (Richardson and Davis 2001). Therefore, better understanding the erosion potential of a given type of soil should help predict scour at bridge piers more accurately. Erodibility is the property that describes the erosion potential of a soil in terms of the energy needed for erosion to occur. If erosion is the transportation or movement of a
Baleshwar Singh - One of the best experts on this subject based on the ideXlab platform.
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Shear Strength and Deformation Behaviour of Glass Fibre-Reinforced Cohesive Soil with Varying Dry Unit Weight
Indian Geotechnical Journal, 2019Co-Authors: Suchit Kumar Patel, Baleshwar SinghAbstract:Proctor compaction and consolidated undrained triaxial tests were carried out to investigate the effects of glass fibre reinforcement on the shear strength and deformation behaviour of a cohesive soil under different compaction states. The fibre diameter was 0.15 mm, varying in length from 10 to 30 mm, and in content from 0 to 4% by Weight of the Dry soil. The separate and joint effects of fibre content, fibre length, confining pressure and Dry Unit Weight on the deviator stress response, pore water pressure response, deformation mode, stiffness and shear strength of the specimens were evaluated. The shear strength of the reinforced soil increases with the moulding Dry Unit Weight, though the optimum fibre content and fibre length remain the same for all Dry Unit Weights. Multiple-regression statistical analysis was carried out to develop an expression for predicting the major principal stress at failure of the glass fibre-reinforced cohesive soil.
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strength and deformation behavior of fiber reinforced cohesive soil under varying moisture and compaction states
Geotechnical and Geological Engineering, 2017Co-Authors: Suchit Kumar Patel, Baleshwar SinghAbstract:An experimental study was carried out to investigate the effects of glass fiber reinforcement on the strength and deformation behavior of a cohesive soil under different compaction states by means of unconfined compression tests. The specimens were prepared with varying fiber contents, fiber lengths, Dry Unit Weight and moisture content other than maximum Dry Unit Weight and optimum moisture content of the soil. From the test results, peak strength, failure axial strain, secant modulus and energy absorption capacity of the reinforced soil specimens were calculated and compared with that of the unreinforced soil. The results showed that the relative benefits of fiber reinforcement are highly dependent on the moisture content and Dry Unit Weight of the soil specimens. The peak strength of the reinforced soil specimen increases gradually with increase in Dry Unit Weight, whereas the improvement of peak strength with moisture content occurs up to optimum moisture content. The brittle failure pattern with a single distinct shear plane of the unreinforced soil specimens is gradually transformed to multi-shear failure pattern along with barreling shape at low fiber content, and then to plastic bulging failure with a network of minor fissures at higher fiber content.
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compaction characteristics of lateritic soil mixed with fly ash and lime
International Journal of Geotechnical Engineering, 2012Co-Authors: Baleshwar Singh, Ravinder GoswamiAbstract:AbstractThe compaction characteristics of a lateritic soil modified with a low-calcium fly ash and lime was investigated in the laboratory. The maximum amount of soil replaced with fly ash was limited to 50%. Lime was added in quantities varying from 2% to 4% of the Dry Weight of soil-fly ash mix. Moisture-Dry Unit Weight relationships were determined for the mixes by using a fresh specimen for each point even after a delay period extending up to 3 days. Fresh specimens were also subjected further to three re-compaction cycles without any delay. The test results indicate that the addition of both fly ash and lime cause immediate reduction in the maximum Dry Unit Weight. Compaction delay leads to a further decrease only for mixes containing lime. However, there is an increase in maximum Dry Unit Weight after re-compaction of the soil-fly ash mixes, and the effect is more pronounced for mixes with lime added.
Matthew A Mcclerren - One of the best experts on this subject based on the ideXlab platform.
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an investigation on erodibility and geotechnical characteristics of fine grained fluvial soils from lower michigan
Geotechnical and Geological Engineering, 2012Co-Authors: Matthew A Mcclerren, Hiroshan Hettiarachchi, Donald D. CarpenterAbstract:Scour and erosion potential of a soil are closely related to each other. Similarities or differences between them have not been defined fully and the terms are often used interchangeably or in association with one another. Erodibility is a property of soil that describes erosion potential. Therefore, a proper understanding of erodibility should help predict scour more accurately. In the past, researchers have looked into erosion of soils with the ultimate objective of understanding the erodibility with respect to the standard geotechnical properties. Most research has shown the difficulties associated with correlating erodibility to any one or more soil properties. The research described in this paper is mainly focused on the relationship between erodibility and Dry Unit Weight of soil with varying fractions of fines. Soils tested using laboratory Jet Erosion Test (JET) indicated that the logarithm of erodibility makes a linear inverse relationship with the Dry Unit Weight. In situ JETs confirmed the range of erodibilities established by the laboratory JETs. The best correlations between erodibility and Dry Unit Weight appeared within a single category of soil as classified by the Unified Soil Classification System. In addition, it was also determined that the logarithm of erodibility is inversely related to the angle of internal friction of the fluvial soils tested during this investigation.
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an investigation on erodibility and geotechnical characteristics of fine grained fluvial soils from lower michigan
Geotechnical and Geological Engineering, 2012Co-Authors: Matthew A Mcclerren, Hiroshan Hettiarachchi, Donald D. CarpenterAbstract:Scour and erosion potential of a soil are closely related to each other. Similarities or differences between them have not been defined fully and the terms are often used interchangeably or in association with one another. Erodibility is a property of soil that describes erosion potential. Therefore, a proper understanding of erodibility should help predict scour more accurately. In the past, researchers have looked into erosion of soils with the ultimate objective of understanding the erodibility with respect to the standard geotechnical properties. Most research has shown the difficulties associated with correlating erodibility to any one or more soil properties. The research described in this paper is mainly focused on the relationship between erodibility and Dry Unit Weight of soil with varying fractions of fines. Soils tested using laboratory Jet Erosion Test (JET) indicated that the logarithm of erodibility makes a linear inverse relationship with the Dry Unit Weight. In situ JETs confirmed the range of erodibilities established by the laboratory JETs. The best correlations between erodibility and Dry Unit Weight appeared within a single category of soil as classified by the Unified Soil Classification System. In addition, it was also determined that the logarithm of erodibility is inversely related to the angle of internal friction of the fluvial soils tested during this investigation.
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laboratory and field investigation on variation of erodibility with Dry Unit Weight of different soils
Proceedings of GeoFlorida 2010: advances in analysis modeling and design West Palm Beach Florida USA 20-24 February 2010., 2010Co-Authors: Matthew A Mcclerren, Hiroshan Hettiarachchi, Donald D. CarpenterAbstract:Better understanding the erodibility of a given type of soil can help predict scour at bridge piers more accurately. In the past, researchers have looked into erosion of soils with the ultimate objective of understanding the erodibility with respect to the other geotechnical properties. Most research has shown the difficulties associated with correlating erodibility to any one soil property. The research described in this paper is about an investigation on erodibility and Dry Unit Weight of soil with varying fractions of fines. Soils tested using laboratory Jet Erosion Test (JET) indicated that the logarithm of erodibility makes a linear inverse relationship with the Dry Unit Weight. In situ JETs confirmed the range of erodibilities established by the laboratory JETs. The best correlations between erodibility and Dry Unit Weight appeared within a single category of soil as classified by the Unified Soil Classification System. Background Two of the most common causes of bridge failure in the United States are flooding and scour accounting for 165 and 78 cases of bridge failure respectively between 1989-2000, which represents over 47% of all bridge failures that occurred. In addition, the failures caused by flooding are also believed to be related to scour (Wardhana and Hadipriono 2003). As such, accurate estimation of bridge scour is essential to protect lives and property while preventing over designing piers that can be costly. Scour prediction relies on empirical or semi-empirical equations, as a means to predict scour but most equations are applied over a range of soil conditions from clean sand to clay without consideration for soil variability. Scour is the erosion of streambed or bank material due to flowing water (Richardson and Davis 2001). Therefore, better understanding the erosion potential of a given type of soil should help predict scour at bridge piers more accurately. Erodibility is the property that describes the erosion potential of a soil in terms of the energy needed for erosion to occur. If erosion is the transportation or movement of a
Charles M O Nwaiwu - One of the best experts on this subject based on the ideXlab platform.
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prediction of maximum Dry Unit Weight and optimum moisture content for coarse grained lateritic soils
Soils and Rocks, 2021Co-Authors: Charles M O Nwaiwu, E.o. & MezieAbstract:Abstract Laboratory compaction of soils is an important aspect in the selection of materials for earthwork construction. Owing to time constraints and concern for depleting resources, it becomes imperative that empirical relationships would be developed to predict compaction parameters, maximum Dry Unit Weight (MDUW) and optimum moisture content (OMC) from easily measured index properties. The aim of this note is to develop empirical relationships between MDUW /OMC and logarithm of compaction energy (E)/fines content: sand content ratio (FC/SdC) for some lateritic soils. Index property tests were carried out on twenty (20) lateritic soils to classify them and obtain the FC/SdC. The soils were compacted at three compaction energies; British Standard Light (BSL), West African Standard (WAS) and British Standard Heavy (BSH). Two models were developed from relationships based on slopes and intercepts derived from MDUW/OMC versus log E plots; one model employs ‘FC/SdC’ and one compactive effort (BSL) while the other model employs only ‘FC/SdC’. The models were validated for robustness with soils used in the development of the models and six (6) other soils not used to develop the models. For the prediction of BSH, the model employing FC/SdC and one compactive effort showed typical errors of ±0.63 kN/m3 and ±0.76% for MDUW and OMC respectively. The model employing only FC/SdC showed typical errors of ±0.4 kN/m3 and ±0.83% for MDUW and OMC respectively. The typical errors are within allowed variations for projects and standards for MDUW and OMC, thus the models are quite robust.
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compactive effort influence on properties of quarry dust black cotton soil mixtures
International Journal of Geotechnical Engineering, 2012Co-Authors: Charles M O Nwaiwu, Samson Mshelia, Joshua DurkwaAbstract:AbstractThe influence of compactive efforts on properties of quarry dust-black cotton soil mixtures was studied using graphical method, two-way analyses of variance and multiple regression analysis. Addition of quarry dust to the black cotton soil resulted to increases in measured values of maximum Dry Unit Weight ( MDUW ), optimum moisture content ( OMC ) as well as California bearing ratio ( CBR ). The observed increases were more pronounced at the highest compactive effort employed in the study. Measured values of free well strain, swell potential ( S p ) and swelling pressure ( P s ) decreased as quarry dust content increased; higher values of the parameters being obtained at higher compactive efforts for S p and P s . The differences in the measured values of MDUW, OMC, CBR, S p and P s resulting from differences in compactive efforts and quarry dust content are statistically significant at...
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properties of ironstone lateritic gravels in relation to gravel road pavement construction
Geotechnical and Geological Engineering, 2006Co-Authors: Charles M O Nwaiwu, I B K Alkali, U A AhmedAbstract:A laboratory investigation was conducted to determine properties of five samples of ‘oolitic ironstone’ lateritic gravel aggregates which are relevant to their use as road construction materials. Measured values of physico-chemical, physico-mechanical as well as index properties and compaction characteristics are similar to those of other lateritic, gravels occurring in West Africa which are used in road pavement applications. These lateritic clayey gravels have good workability as engineering construction materials and are rated fair to good as road aggregates in terms of probable in-situ behaviour based on water absorption values. Relationships between maximum Dry Unit Weight and optimum moisture content as well as those between California bearing ratio and some derived soil parameters such as grading modulus, plasticity product or plasticity modulus can be described using a third-order polynomial function. The maximum Dry Unit Weight has a bimodal frequency distribution and can be predicted from logarithm to base 10 of compaction energy with fairly good accuracy.
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hydraulic conductivity of compacted lateritic soil
Journal of Geotechnical and Geoenvironmental Engineering, 2005Co-Authors: Charles M O Nwaiwu, Kolawole J. OsinubiAbstract:Hydraulic conductivity tests were conducted on three samples of lateritic soil obtained from the same borrow area and having a narrow range of fines content. Eighty four specimens were compacted at various molding water contents and then permeated with distilled/de-ionized water in the laboratory. Test results show that hydraulic conductivity of the soils decreased with the increase in Dry Unit Weight and initial saturation, especially at higher fines content. Hydraulic conductivity values less than 1× 10−9 m∕s can be obtained at Dry Unit Weights (wet of optimum) and initial saturations greater than 16.0 kN∕ m3 and 86.0%, respectively, provided a minimum compaction energy equal to the British Standard Light effort is used. The difference in hydraulic conductivity values due to variations in molding water contents and compactive efforts are statistically significant as shown by the two-way analysis of variance tests.
