Dissertations / Theses: 'Soil compaction'

1

Browne, Michael John. "Feasability of using a gyratory compactor to determine compaction characteristics of soil." Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/browne/BrowneM1206.pdf.

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2

Keller, Thomas. "Soil compaction and soil tillage - studies in agricultural soil mechanics /." Uppsala : Dept. of Soil Sciences, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a489.pdf.

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3

Troost, Jan J. "Factors influencing laboratory vibratory compaction." Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/17651.

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Includes bibliography.
The thesis consists of a literature review and a limited experimental investigation in a soils laboratory. The objective of the literature review is to determine what standard laboratory test methods based on vibration exist for the control of compaction, to what soil types these tests are applicable and what the factors are which affect laboratory vibratory compaction. The study revealed that extensive research has been carried out in the USA and Europe, where standard laboratory compaction tests exist for the determination of the maximum dry density of cohesionless, free-draining soil. The US methods are based on the use of a vibratory table, while the European practice is based on the use of a vibratory tamper. No standard tests appear to exist for soil exhibiting cohesion, though limited research has been carried out in the USA into the behaviour of such soils under laboratory vibratory compaction. The factors; frequency, amplitude, mould size and shape surcharge intensity and manner of application, soil type, time of vibration, number of layers and moisture content are all reported to have an effect on the maximum dry density achievable. It has been recognised that significant interaction occurs between the factors affecting vibratory compaction, but the extent of the interaction appears to be only partly understood. The objective of the limited experimental program was to determine whether a specific graded crushed stone could be compacted to Modified AASHTO maximum dry density with a laboratory vibratory compaction technique using a vibratory table, and how this could best be achieved. The effects on dry density of changing the frequency, the time of vibration, mould size, surcharge pressure, grading and moisture content were investigated. It is concluded that the graded crushed stone in question can be compacted to Mod. AASHTO maximum dry density but that before reliable reproducible results can be achieved with this type of test further work is necessary. Such research should be aimed at investigating the interaction effect between the amplitude of vibration, the soil type and the type and intensity of the applied surcharge pressure.

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4

Mapfumo, Emmanuel. "Soil and plant response to compaction." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23028.pdf.

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5

Duval, Jean. "Assessing porosity characteristics as indicators of compaction in a clay soil." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59275.

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Persistent soil compaction by heavy-axle-load vehicles is a growing concern for the long-term productivity of clay soils. For optimum soil management, however, we must be able to evaluate adequately soil structural damages. This study compares different methods of assessing soil structure as affected by compaction and subsoiling treatments in a clay soil under corn production.
The tests used were: total porosity as calculated from densimeter readings and from soil cores; structural porosity; water desorption characteristics; and soil profile examination. These tests were performed in three layers of 20 cm and evaluation was based on their practicality and their ability to differentiate between treatments and to correlate with corn yield.
The results confirm that total porosity is a poor indicator of compaction in the subsoil. In soil profile assessments, ped descriptions were preferable to examination of pores. Water content and saturation deficit at $-$4.0 and $-$100 kPa were the best indicators of treatments and plant response.

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6

Stinghen, Geovanne Silva. "Assessment of nitrogen efficiency in maize due to soil compaction and changes in soil physical properties /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1422967.

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7

Malvajerdi, Ahmad Sharifi. "Development of a soil compaction profile sensor." Thesis, Cranfield University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414666.

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8

Allen, Sarah. "The low energy dynamic compaction of soil." Thesis, Cardiff University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338145.

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9

Nau, Kevin R. "Air permeability : a measure of soil compaction." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299081025.

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10

Pengthamkeerati, Patthra. "Soil physical and microbiological properties affected by soil compaction, organic amendments and cropping in a claypan soil /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3164537.

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11

Jones, Mark W. "Soil compaction caused by timber harvesting in central Appalachian hardwood forests." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=2926.

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Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains viii, 52 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 47-52).

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Sadeghi, Tehrani Faraz. "An investigation of continuous compaction control systems." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 435 p, 2009. http://proquest.umi.com/pqdweb?did=1889078521&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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13

Schäffer, Beat. "Compaction of restored soil by heavy agricultural machinery /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17273.

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14

Griffith, Christopher J. "Soil improvement through vibro-compaction and vibro-replacement." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26256.

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15

Assaeed, A. M. "Soil compaction and plant performance of forage crops." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234679.

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16

Clement, Brian Richard. "Development of a continuously measuring soil compaction sensor." Connect to resource, 2000. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1202401877.

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17

Chen, Guihua. "Alleviation of soil compaction by Brassica cover crops." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9517.

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Thesis (Ph .D.) -- University of Maryland, College Park, 2009.
Thesis research directed by: Dept. of Natural Resource Sciences. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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18

Frost, John Peter. "Some effects of machinery traffic, soil compaction and soil loosening on grass yield." Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317071.

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19

Tracy, Saoirse Rosanna. "The response of root system architecture to soil compaction." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13037/.

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Soil compaction has been described as the most serious environmental problem caused by conventional agriculture, as it results in several stresses which may interact simultaneously, including increased soil strength, decreased aeration and reduced hydraulic conductivity. Root system architecture (RSA) is the arrangement of roots within the soil matrix and is important because the specific deployment of roots within the soil can determine soil exploration and resource uptake. As roots deliver water and nutrients to growing plants, whilst also providing anchorage, their importance cannot be overstated. Yet, our understanding of how roots interact with the surrounding soil, especially at the micro-scale level, remains limited because soil is an opaque medium, so preventing roots from being visualised without disturbing them. Destructive techniques are commonly employed for the analysis of RSA, however this can result in the loss of key information concerning root architecture, such as elongation rates and root angles and important soil characteristics such as soil structure and pore connectivity. However, X-ray Computed Tomography (CT) has been shown to be a promising technique for visualising RSA in an undisturbed manner. The species considered in this thesis were wheat (Triticum aestivum L.) and tomato (Solanum lycopersicum L.). Further information regarding the response of roots to soil compaction has been achieved through the use of X-ray CT, automatic root tracing software and novel image analysis procedures. Soil compaction significantly affected root length, volume, surface area, angle, diameter, elongation rates and root path tortuosity, however the influence of soil texture on root responses to soil compaction was significant. Moderate compaction benefits root growth in clay soil, possibly due to the greater nutrient and water holding capacity, but adversely affected root growth in loamy sand. The results suggest that there is an optimum level of soil compaction for the different soil types. Roots elongated rapidly between 2-3 days after germination (DAG), it is hypothesised that is related to the mobilization of seed storage substances to the growing roots. The use of transgenic mutants of tomato with altered levels of abscisic acid (ABA) has provided a greater insight into the role of ABA in mediating root responses to soil compaction. This work will enable better phenotyping of plant varieties with enhanced root system traits for resource foraging and uptake. Knowledge of the responses of root systems in heterogeneous soil is vital to validate root phenotypes and overcome future food security challenges.

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20

Chung, Young-Jun. "Bearing capacity of cohesionless soil after the dynamic compaction." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364882.

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21

Ess, Daniel R. "Cover crop residue effects on machine-induced soil compaction." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-164819/.

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22

O'Reilly, Myles Patrick. "Predictions of the performance of compaction plant." Thesis, Heriot-Watt University, 1985. http://hdl.handle.net/10399/1622.

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23

Montagu, Kelvin D. "Whole plant response to soil compaction : from field practices to mechanisms /." View thesis View thesis, 1995. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030522.092251/index.html.

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24

Lavoie, Gilbert. "Economics of soil compaction due to machinery traffic in Quebec." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61844.

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25

Hamad, Falah D. "The consequences of land management, particularly compaction, on soil ecosystems." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/43043.

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One of the many current global problems is soil degradation. A major contributor to soil degradation is compaction. This is caused by overgrazing by livestock or the use of heavy agricultural machinery. Three study areas in Britain (Leicester, Wicken Fen and Loddington) and two in Kenya (Bogoria and Naivasha) were established. The following soil physical and chemical properties were measured: particle size, total porosity, penetration resistance, hydraulic conductivity, organic matter content and pH. And the following biotic properties were measured: invertebrate biodiversity, abundance, biomass, decomposition rates and carbon dioxide efflux. Firstly, a causal relationship was established between artificial compaction and the response of many soil physical and biotic properties. Total porosity, hydraulic conductivity, biodiversity, abundance and biomass, and CO2 efflux were reduced; penetration resistance increased. Organic matter content and pH remained unaffected. Different land-management practices were studied by investigating their inferred effects on the soil physical and biotic properties. Different practices were investigated as follows: woodland (Wicken Fen, Loddington and Naivasha); pasture (Wicken Fen, Loddington, Bogoria); no-till cultivation (Wicken Fen, Loddington); restoration/conservation cultivation (Bogoria), organic cultivation (Naivasha), overgrazed (Bogoria) and tilled (Wicken Fen, Loddington, Naivasha). A Compaction Index, comprising data from total porosity and penetration resistance, was devised to describe the physical effects of different management-practices on the soil ecosystem. Management practices that resulted in low Compaction Indices were no-till, pasture, restoration /conservation cultivation and organic cultivation. High values of the compaction Index were found in all tilled or overgrazed sites. Woodland often gave intermediate values, especially at Loddington. Biotic properties of the different soils were negatively correlated with the Compaction Index, with British pasture sites having the highest values for the biotic parameters, except decomposition rate, which was highest in no-till sites. The importance of the use of cultivation techniques sensitive to the health of soil ecosystems is stressed.

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26

Roberts, Charles A. "A fluid injection device for the measurement of soil compaction." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299077620.

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27

Ishihara, Katsuji. "At-rest and compaction-induced lateral earth pressures of moist soils." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-07122007-103943/.

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28

Pang, Mei-yee. "The nature and magnitude of soil compaction in different human-modified habitats in Hong Kong." Click to view the E-thesis via HKUTO, 2001. http://sunzi.lib.hku.hk/hkuto/record/B42576520.

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29

Kachamba, Daud Jones. "Impact of harvesting machinery on soil physical parameters : evaluation of ProFor model in three main forestry regions of South Africa /." Link to the online version, 2007. http://hdl.handle.net/10019/648.

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30

Chen, Cheng-Wei. "A constitutive model for fiber-reinforced soils." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4768.

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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Typescript. Vita. Title from title screen of research.pdf file (viewed on March 6, 2009) Includes bibliographical references.

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31

Romero, Ricardo J. "Development of a constitutive model for fiber-reinforced soils /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3115585.

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32

Montagu, Kelvin D. "Whole plant response to soil compaction : from field practices to mechanisms." Thesis, View thesis View thesis, 1995. http://handle.uws.edu.au:8081/1959.7/433.

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This thesis examines the growth response and inter-relationships between shoots and roots of plants grown in compact soil. In the field, two topsoil and two subsoil conditions were created with five vegetable crops sequentially grown. Between 6 and 12% of the root system grew in the compact subsoil, which had a soil strength of 3.1 c.f. 1.9 MPa in the loosened subsoil. Both the root length density (Lv) and the specific root length were lower in the compact subsoil (80% and 30%, respectively). This had no effect on shoot growth when water and nutrients were well supplied. Compensatory root growth in the lose soil above the compact subsoil occurred in broccoli plants. As a result plants grown in soil with or without a compact subsoil had a similar total root length but with altered root distribution. When the water and nitrogen supplied to the soil was reduced, the lower subsoil Lv in the compact subsoil did not restrict water or N acquisition. This was possibly due to a large increase in the specific uptake per unit length of root, by the fewer roots in the compact subsoil. Compared to the subsoil treatments, only small changes in topsoil physical properties occurred when tillage was ceased. From the field trials the proportion and time of root growth into compact soil appeared important in determining the plant response. In a series of split-root experiments (horizontal and vertical arrangements of compact and loose soil) compensatory root growth in the loose soil only occurred when the root system was exposed to horizontally compact soil When compensatory root growth did not occur shoot growth was reduced. This resulted in there being a close relationship between total root length and leaf area. Further test results support a direct effect of mechanical impedance on shoot growth with a rapid (within 10 minutes) and large (50%) reduction in leaf elongation occurring when roots were mechanically impeded. In the field only plants whose roots were totally exposed to compact soil had reduced shoot growth with very compact subsoil having no effect.

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33

Sanchez, Pedro Andrade. "Design, development, and field evaluation of a soil compaction profile sensor /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.

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34

Javadi, Arzhang. "Reducing deep soil compaction through strain modification under different wheel arrangements." Thesis, Cranfield University, 2002. http://dspace.lib.cranfield.ac.uk/handle/1826/4280.

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New mechanisation methods associated with increasing loads have the potential to cause undesirable deep compaction, which is difficult, expensive and in some cases impossible to alleviate. Avoiding or reducing the risk of deep compaction seems to be the most straightforward solution to compaction management. Previous research indicates that some benefits can be achieved through interactions between cultivation tines or other implements, in terms of the magnitude of forces and the extent of soil deformation. Interaction within wheel arrangements could have benefits for reducing deep soil compaction. This study aimed to reduce the risk of deep soil deformation by locally modifying soil conditions through interactions in order to increase soil resistance and hence load support in the surface layers. To test the hypothesis, the research was based on soil mechanics theories and failure mechanisms related to bearing capacity in order to identify the major factors influencing load support and soil displacement. The nature of soil failure patterns, interaction behaviour, soil deformation and load/sinkage relationships were investigated under a wide range of dual and triple spaced footings/wheels configurations. Small-scale tests using rectangular plates were firstly conducted in a glass-sided tank. These initial tests were followed by larger-scale tests in a soil bin and in the field under different soil conditions using actual wheels, spaced and positioned as in the footing tests. The results indicate that it is possible to reduce soil displacement at depth by increasing load support in the soil surface layers through the interaction between spaced wheel arrangements. It was shown that different interaction modes occurred under dual configurations depending on the spacing between them. A locally compacted zone was created between the wheels under dense interaction conditions, increasing surface support. Surface support was increased further through a surcharging effect achieved by placing a third footing/wheel between and higher than the side wheels (triple arrangement). The central static interaction zone maximised the surface resistance locally under these configurations. Although single wide section wheels such as Terra tyres can tolerate higher loads at lower pressures, from a soil failure point of view, this is usually associated with large active and passive failure zones inducing deeper soil deformation. Triple spaced wheel arrangements with similar diameter wheels kept soil displacements shallower whilst carrying a similar load to a single very wide wheel with the same overall contact pressure. Reductions of up to 50% in the depth of soil displacement were achieved with the triple arrangements for the same load. These spaced arrangements can therefore be recommended as promising replacement for single wide wheel under heavy machinery application in practical situations. Benefits from the spaced arrangements are achieved in two ways: firstly by increasing surface support through creating locally compacted zones and secondly by reducing the size of active and passive failure zones causing shallower deformations. Stony soils provide more surface support than stoneless soils and also non-uniform soil with a denser layer at tillage depth can tolerate a greater load for a given sinkage compared with uniform homogenous soil. A mathematical model was developed to predict the vertical force under interacting shallow footings and showed an acceptable level of agreement with the experimental results. The model can be used to estimate the extent of the rupture distance of the side passive planes to assist in identifying appropriate spacings and interaction modes for spaced wheel arrangements.

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35

Montagu, Kelvin D., of Western Sydney Hawkesbury University, Faculty of Agriculture and Horticulture, and School of Horticulture. "Whole plant response to soil compaction : from field practices to mechanisms." THESIS_FAH_HOR_Montagu_K.xml, 1995. http://handle.uws.edu.au:8081/1959.7/433.

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This thesis examines the growth response and inter-relationships between shoots and roots of plants grown in compact soil. In the field, two topsoil and two subsoil conditions were created with five vegetable crops sequentially grown. Between 6 and 12% of the root system grew in the compact subsoil, which had a soil strength of 3.1 c.f. 1.9 MPa in the loosened subsoil. Both the root length density (Lv) and the specific root length were lower in the compact subsoil (80% and 30%, respectively). This had no effect on shoot growth when water and nutrients were well supplied. Compensatory root growth in the lose soil above the compact subsoil occurred in broccoli plants. As a result plants grown in soil with or without a compact subsoil had a similar total root length but with altered root distribution. When the water and nitrogen supplied to the soil was reduced, the lower subsoil Lv in the compact subsoil did not restrict water or N acquisition. This was possibly due to a large increase in the specific uptake per unit length of root, by the fewer roots in the compact subsoil. Compared to the subsoil treatments, only small changes in topsoil physical properties occurred when tillage was ceased. From the field trials the proportion and time of root growth into compact soil appeared important in determining the plant response. In a series of split-root experiments (horizontal and vertical arrangements of compact and loose soil) compensatory root growth in the loose soil only occurred when the root system was exposed to horizontally compact soil When compensatory root growth did not occur shoot growth was reduced. This resulted in there being a close relationship between total root length and leaf area. Further test results support a direct effect of mechanical impedance on shoot growth with a rapid (within 10 minutes) and large (50%) reduction in leaf elongation occurring when roots were mechanically impeded. In the field only plants whose roots were totally exposed to compact soil had reduced shoot growth with very compact subsoil having no effect.
Doctor of Philosophy (PhD)

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36

Silver, Robert Kenneth. "The compaction and permeability performance of mineral landfill liners." Thesis, University of the West of Scotland, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309630.

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37

Li, Yanfeng. "Use of a BCD for compaction control." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/2696.

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Compaction of soil is essential in the construction of highways, airports, buildings, and bridges. Typically compaction is controlled by measuring the dry density and the water content of the compacted soil and checking that target values have been achieved. There is a current trend towards measuring the soil modulus instead or in addition to density. The reasons are that the density measurements are made using nuclear density meter, an undesirable tool in today??s political environment and that pavement design uses moduli as an input parameter. Although there are many apparatus available to measure soil modulus in the field such as Falling Weight Deflectometer, Dynamic Cone Penetrometer and Seismic Pavement Analyzer, a light weight and easy to use device which can measure the soil modulus fast and accurately is in great need. Briaud Compaction Device (BCD) is a portable device which can measure a soil modulus in several seconds. The principle of the BCD is to use the bending of a plate resting on the ground surface as an indicator of the modulus of the soil below. Numerical simulations show that within a certain range, the soil modulus is simply related to the plate bending. Strain gauges are glued on the top of the plate of BCD and a double half Wheatstone bridge is used to measure the strain. BCD tests were done in parallel with plate tests of the same size. A good correlation was found between the ratio of the plate pressure over the bending strain measured with a BCD and the reload soil modulus obtained from the plate test. This correlation can be incorporated into the BCD processor to display the soil modulus directly. To transit from dry density based compaction control to modulus based compaction control, BCD tests were also performed in the laboratory on top of a soil sample compacted inside the Proctor mold followed by plate tests. That way, a soil modulus versus water content curve is developed which parallels the approach for the dry density versus water content. The soil modulus versus water content curve can be used to provide the target values for compaction control in the field.

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Regmi, Sanjeev. "EFFECT OF PLASTICITY AND INITIAL COMPACTION CONDITIONS ON SOIL WATER CHARACTERISTICS CURVE OF FINE-GRAINED SOILS." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2625.

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The soil water characteristics curve (SWCC) of a soil plays an important role in study of unsaturated soil mechanics. The behavior of unsaturated soil is a complex phenomenon to understand and the direct measurement of unsaturated soil properties in laboratory or in field is costly and time consuming. Knowing the SWCC of a soil is useful in estimating the unsaturated property of a soil, which is close to the natural soil conditions and can be used in effective design procedure. The present study deals with the effect of plasticity and initial compaction conditions of a soil in the SWCC by using SWC-150 (Fredlund SWCC device) and WP4C dewpoint potentiometer. The test data obtained from both the device were best fitted using Fredlund and Xing (1994) equation (FX), Van Genutchen (1980) equation (VG), Burdine (1958) equation, and Mualem (1976) equation.

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Nazhat, Yahya Nazar Yahya. "Behaviour of sandy soil subjected to dynamic loading." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9435.

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This thesis presents the kinematics occurring during lab-based dynamic compaction tests using high speed photography and image correlation techniques. High speed photography and X-ray microtomography have been used to analyse the behaviour of sandy soil subjected to dynamic impact. In particular, the densification mechanism of granular soils due to dynamic compaction is the main theme of the thesis. High speed photography and digital image correlation (DIC) techniques have enabled the deformation patterns, soil strains and strain localisations to be observed. Image correlation and X-ray scans revealed the formation, rate and growth of narrow tabular bands of intense deformation and significant volumetric change and provided answers towards a better understanding of the densification mechanism in dry granular soils due to dynamic compaction. As a quantitative tool, high speed photography has allowed the propagation of localised deformation and strain fields to be identified and has suggested that compaction shock bands control the kinematics of dynamic compaction. The displacement and strain results from high speed photography showed that soil deformation in the dynamic tests was dominated by a general bearing capacity mechanism similar to that widely stated in classic soil mechanics texts. Comparative static loading tests have been conducted to enable the dynamic effects to be clearly distinguished. This has enabled the densification process taking place below the soil surface to be investigated and identified. Simulations of the physical models were carried out using LS-DYNA finite element formulations for comparison and verification purposes. The FE simulations verified the general characteristics from the photography findings. However, simulation results were unable to predict the exact details of the strain localisation due to surface impacts during physical model tests.

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40

Mobley, Thomas Jackson Melville Joel G. "Erodibility testing of cohesive soils." Auburn, Ala, 2009. http://hdl.handle.net/10415/1776.

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41

Gameda, S. "Quantification, predictability and alleviation of high axle load compaction in Quebec soils." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39818.

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Soil structure and crop response under annual compactive loads of 10 and 18 t/axle and compaction alleviation treatments were assessed in a continuous corn production system. The alleviation treatments consisted of chemical conditioning with a non-ionic surfactant, and subsoiling with narrow-tined and winged implements. Parameters utilized for determining effects on soil structure were bulk density, water retention characteristics and soil profile characteristics. Significant topsoil and subsoil compaction resulted from both loading levels. Crop yield reductions due to compactive loading ranged from 18 to 27% under optimal weather conditions and were as high as 55 to 86% under adverse weather conditions. Soil amendments by chemical conditioning had no beneficial effect on soil structure or crop yields. Inter-row subsoiling with narrow-tined and winged subsoilers was effective in reducing soil compaction and increasing crop yields.
Soil bulk density measurements gave good indication of overall compaction to a depth of 0.4 m and correlated well with crop yields, but were unable to locate differences between compactive treatments. Water retention characteristics indicated significant differences between compactive treatments to a depth of 0.6 m. Soil profile characteristics were useful for determining ped type and size as well as rooting depth and gave the best overall assessment of compaction alleviation effects.
Studies were also conducted to develop a method for predicting soil compactibility that would serve to manage soil compaction at the farm level. Preliminary studies focused on the determination of soil material properties for predicting bulk density changes under applied loads. Further investigations were conducted on the variations in constrained modulus, cone index and soil bulk density values under uniaxial loading. A model relating constrained modulus as a function of cone index, bulk density and soil moisture content was developed. Subsequent studies conducted yielded significant relationships between penetration resistance and soil compactibility as indicated by constrained modulus and coefficient of compressibility. Relationships obtained between penetration resistance and parameters of compactive work and bulk density change indicated the feasibility of assessing soil compactibility at the farm level.

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42

Ekrami-Nasab, Nader. "An advanced numerical model for the dynamic compaction of unsaturated granular soils." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/608.

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43

Wang, ShuHong. "Soil substrate selection for urban trees under deicing salt and compaction conditions." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82446.

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The effects of high sodium chloride (NaCl) levels on Na and nutrient retention of three soil substrates and on littleleaf linden growth in different soil substrates were studied in the laboratory and the greenhouse, within the framework of a substrate selection program for trees planted in downtown Montreal. In addition, the effects of the structural soil (SS) compaction were studied in the first greenhouse experiment. The first greenhouse experiment was established in a factorial arrangement of four soils x four salt levels in a completely randomized design with five replicates. The four soil types were (1) L with a bulk density (BD) of 1.53 g/cm3, (2) LP with a BD of 1.26 g/cm3, (3) SS with a BD of 1.8 g/cm 3 (SS1.8), and (4) SS with a BD of 2.0 g/cm3 (SS2.0). The second greenhouse experiment had a split plot design. Two fertilization levels (with fertilizer and without fertilizer) were randomly arranged as the main plots on ten benches. Within each main plot, the combinations of three NaCl levels (0, 0.5 and 1.0 g NaCl/kg soil) and three soil substrates (L with a BD of 1.40 g/cm3, LP with a BD of 1.13 g/cm 3 and SS2.0) were randomized in the sub-plots. Results from the laboratory leaching experiment indicated that SS had the fastest Na leaching rate and highest Na loss, while LP retained more Na than SS or L. (Abstract shortened by UMI.)

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44

Brereton, Jeremy Charles. "The sensitivity of barley, field beans and sugar beet to soil compaction." Thesis, University of Nottingham, 1986. http://eprints.nottingham.ac.uk/13931/.

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The sensitivity of spring barley (Hordeum vulgare, cv. Carnival), field beans (Vicia faba, ev. Maris Bead) and sugar beet (Beta vulgaris,cv. Monoire) to topsoil compaction induced by tractor wheelings, post sowing, on a coarse gravelly loam of the Arrow series was investigated in 1983 and 1984. The study revealed that in both years topsoil compaction increased the dry bulk density, vane shear strength and cone resistance of the soil. Although compaction reduced only the plant population of sugar beet in 1983 (by 35%) in 1984 it both delayed emergence and decreased the field bean, spring barley and sugar beet populations by 41%, 50% and 64% respectively. In 1983 the order of sensitivity of crop yield to soil compaction was spring barley < field beans

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Hussain, Ahmed. "Soil compaction : mediation of plant responses by root-sourced ABA and ethylene." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285458.

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46

Wersäll, Carl. "Frequency Optimization of Vibratory Rollers and Plates for Compaction of Granular Soil." Doctoral thesis, KTH, Jord- och bergmekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187352.

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Vibratory rollers are commonly used for compaction of embankments and landfills. This task is time consuming and constitutes a significant part of most large construction and infrastructure projects. By improving the compaction efficiency, the construction industry would reduce costs and environmental impact. This research project studies the influence of the vibration frequency of the drum, which is normally a fixed roller property, and whether resonance can be utilized to improve the compaction efficiency. The influence of frequency on roller compaction has not before been studied but the concept of resonance compaction has previously been applied successfully in deep compaction of fills and natural deposits. In order to examine the influence of vibration frequency on the compaction of granular soil, small-scale compaction tests of sand were conducted under varying conditions with a vertically oscillating plate. Subsequently, full-scale tests were conducted using a vibratory soil compaction roller and a test bed of crushed gravel. The results showed that resonance can be utilized in soil compaction by vibratory rollers and plates and that the optimum compaction frequency from an energy perspective is at, or slightly above, the coupled compactor-soil resonant frequency. Since rollers operate far above resonance, the compaction frequency can be significantly reduced, resulting in a considerable reduction in fuel consumption, environmental impact and machine wear. The thesis also presents an iterative equivalent-linear method to calculate the frequency response of a vibrating foundation, such as a compacting plate or the drum of a roller. The method seems promising for predicting the resonant frequency of the roller-soil system and can be used to determine the optimum compaction frequency without site- and roller-specific measurements.

QC 20160613

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47

Stropki, Cody L., and Roy Jemison. "Restoration Treatments in the Middle Rio Grande Bosque: Effects on Soil Compaction." Arizona-Nevada Academy of Science, 2003. http://hdl.handle.net/10150/296619.

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Rosen, Matthew(Matthew F. ). "Systems analysis, design, and testing for an agricultural soil compaction sensing device." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122614.

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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 110-117).
The World Resources Institute (WRI) and United Nations Food and Agriculture Organization (FAO) estimate that global agricultural food production will need to increase 56% between 2010 and 2050 to meet projected caloric demands of the growing population. Given the finite amount of global land area as well as the impacts agricultural land-use and production have on greenhouse gas emissions (GHGs), achieving this increase in consonance with climate change reduction goals presents a formidable challenge. In the past, large yield improvements have been realized from genetically modified seeds, synthetic fertilizers and pesticides, increased mechanization, and improved irrigation, but these innovations have also brought negative side effects. For example, the increasing weight of mechanized farm equipment has led to significant man-made soil compaction.
Soil compaction is the increase in bulk density, or reduction of air pore space, in a soil matrix, and it can lead to restricted root growth, poor water and nutrient infiltration, and reductions in yield. Specifically, man-made compaction has been estimated to lead to 15-20% reductions in crop yield, leading to $40-45 Billion in annual financial losses in the United States alone. Mechanical tillage is one of the most common remedies for loosening compacted soil, but the process damages soil structure and overall soil health, making it a solution that should optimally be used sparingly, only in areas where soil is severely compacted. A key challenge to enabling this, however, is compaction sensing and mapping at the field scale. In response to this challenge, a research project was undertaken through MIT Beaver Works, a collaboration with MIT Lincoln Laboratory, to explore systems-based solutions for real-time soil compaction sensing and mapping.
Through that work, a high-level system design for measuring soil compaction at the field scale was proposed based on electromagnetic sensing, including the use of ground penetrating radar (GPR) and electromagnetic induction (EMI) sensors. This thesis aims to address the highest risk aspects of the proposed approach through modelling, laboratory testing, and field testing, progressing theoretical results into increasingly more realistic settings to better understand practical limitations and potential challenges with the technical approach.
by Matthew Rosen.
S.M. in Engineering and Management
S.M.
S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering

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Barbosa, Luís Alfredo Pires. "Compactação do solo gerada por pneus de alta flutuação de eixo livre e trativo." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256834.

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Orientador: Paulo Sérgio Graziano Magalhães
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
Made available in DSpace on 2018-08-20T20:08:08Z (GMT). No. of bitstreams: 1 Barbosa_LuisAlfredoPires_M.pdf: 3080988 bytes, checksum: cb9123dca7959f9d728490292de1f6e9 (MD5) Previous issue date: 2012
Resumo: O aumento da mecanização das lavouras gera o emprego de máquinas cada vez mais potentes e, a potência possui relação direta com o peso. Aumentando-se o tráfego de máquinas pesadas sobre o solo o emprego do pneu correto é de suma importância para se minimizar os efeitos da compactação. Com as diferenças entre os modelos de pneus de alta flutuação para eixos livres e trativos (com garras) e o comum emprego de pneus trativos em eixos livres devido ao seu custo de imposto ser reduzido, questionou-se a possibilidade de o emprego do pneu mais barato estar prejudicando a produtividade, pelo fato de apresentar uma área de contato possivelmente menor. Objetivou-se ao estudo comparativo entre dois modelos de pneus de alta flutuação da mesma medida, porém um para eixos livres e outro para eixos trativos. Os experimentos foram conduzidos em caixa de solos e também em superfície rígida, sob condições controladas, realizando-se ensaios estáticos para duas cargas radiais (16 e 29 kN), medindo-se deformações, áreas de contato e compactação do solo, sendo feita uma análise estatística fatorial, com os fatores pneu e carga, sendo realizados 8 ensaios, totalizando 32 observações. Obteve-se como resultados, deformações maiores para o pneu trativo, bem como área de contato maior e compactações menores, que o pneu de eixo livre, isso porque a área de contato do pneu trativo envolve não somente as garras, mas também o fundo íncavo (região entre garras), para o solo estudado, e o fato do pneu possuir uma quantidade de composto de borracha menor em sua banda de rodagem, quando comparado com o pneu de eixo livre, aumenta a flexibilidade da rodagem, melhorando sua capacidade de deformação e consequentemente aumentando sua área de contato com o solo
Abstract: The increased mechanization in farming generates employment of ever more powerful machines, and power has direct relationship with the weight. Increasing traffic of heavy machinery on the ground the use of correct tire is of paramount importance to minimize the effects of compaction. With the differences between models of high-flotation tires for free and trative axes, especially regarding the presence of claws, and the common use of tires trative on free axes because of the cost of tax be reduced, questioned the possibility of employment tire cheaply be hindering productivity, because this has a contact area possibly lower. The objective is then to the comparative study between two models of high-flotation tires the same size, but one for free axes and another for trative axes. The experiments were conducted in soil bin and also in rigid surface, under controlled conditions, performing static tests for two radial loads (16 and 29 kN), by measuring deformation, contact areas and soil compaction, and made a factorial statistical analysis with the tire and load factors, was conducted 8 tests, totaling 32 observations. Was obtained as result, larger deformations for the trative tire as well as larger contact area and less compaction of the soil that tire of free axis, that because the contact area of the tire tractive involves not just the claws, but also the region between them and the fact that the tire has a much lower rubber compound in its tread, when compared with tire of free axis, increases flexibility, enhancing their ability to deformation and consequently increasing its contact area with the ground, reducing the compaction of soil
Mestrado
Maquinas Agricolas
Mestre em Engenharia Agrícola

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50

彭美兒 and Mei-yee Pang. "The nature and magnitude of soil compaction in different human-modified habitats in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B42576520.

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Dissertations / Theses on the topic 'Soil compaction'

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