Showing papers on "Soil stabilization published in 1984"

The use of high energy moisture characteristic to assess soil stability

Abstract: The laboratory method of determining aggregate stability introduced by Childs in 1940 is reconsidered. A convenient and quick method of interpreting the experimental results is presented and provides the structural index for a given soil treatment. The ratio of the structural indices for two soil treatments provides the stability ratio, which is of relevance to erosion and pedogenetic studies of structure. Illustrative results show that pretreatments such as air drying, grinding and sieving affect the structural index and stability ratio.

Method for soil stabilization and fugitive dust control

Abstract: A method of enhancing the geotechnical properties of soil materials so as to control soil erosion including fugitive dust by treating the soil with a mixture of polyacrylic acids or polyacrylates, a dibasic acid or acid salt and a wetting agent in water utilizes an aqueous solution of a polyacrylate emulsion, (said active polymer having a Mw of 1-5 million), sodium citrate and a surfactant (nonylphenol plus 10 moles ethylene oxide). The mixture is applied directly to the soil to be stabilized in either diluted or undiluted form whereby surface erosion in both quiescent areas and road beds can be controlled.

Effect of vegetation on slope stability

Abstract: Two ways are considered in which vegetation can affect slope stability: changes in the soil moisture regime and contribution to soil strength by the roots. Simple analytical models that may be used to calculate water infiltration into soil and soil reinforcement by roots are reviewed and their applications to stability problems are illustrated by examples. The need for reliable field data to support the analytical models is emphasized.

The determination of volume change properties in expansive soils

Abstract: Interactive mechanistic models of expansive soil behaviour require as input data, a number of soil variables, which can describe volume change in expansive clays. Perhaps, the most useful variable is the change in volumetric or dimensional strain per unit change in soil suction. This variable, analogous to the coefficient of volume change m{v}, used in consolidation theory, has previously been defined as the 'Instability' Index. This variable is not a constant, but varies at least with stress, soil suction, direction of change, previous history. This paper describes several methods developed by the Soil Engineering Group, Division of Soils, CSIRO for determining this variable. Results for several soil profiles in the Adelaide, Melbourne and Darling Downs areas of Australia are discussed. Some comparisons with data obtained from ground movement at depth installations in the Adelaide area are also presented.

Properties of cement and lime-fly ash stabilized aggregate

Abstract: Potential application of cement-fly ashaggregate, lime-fly ash-aggregate and limecement-fly ash-aggregate mixtures in pavement construction is reviewed in this paper. Engineering properties such as moisturedensity relationship, compressive strength, flexural strength, dry shrinkage, and freeze-thaw durability are summarized on the basis of past studies. Dry shrinkage and freeze-thaw characteristics of cement and lime-fly ash-aggregate mixtures containing sub-bituminous, self-cementitious Alberta fly ashes were evaluated in the laboratory. The stabilized aggregates are attractive for use in pavement structures because of their high strength and low drying shrinkage characteristics. Lime-fly ash stabilized aggregates are observed to shrink more than cement-fly ash stabilized aggregate. It is also concluded that the materials investigated may perform reasonably well under moderate freeze-thaw conditions in the base courses of pavements. Further research should be conducted to evaluate durability of such materials under appropriate freezethaw conditions.

Performance of preloaded and stage-loaded structures on soft soils in Trinidad

Abstract: Preloading and stage-loading operations were carried out at an industrial plant site in Trinidad, which is underlain by about 10 m of lightly overconsolidated recent sediments. A series of drained stress controlled triaxial tests and oedometer tests were carried out to define the yield envelope for these deposits. Filling of large diameter water storage tanks was controlled by computing the effective stress paths during loading and relating the effective stress states to the yield envelope. The objective of this procedure was to prevent overstressing of large zones within the foundation soils and thereby to minimize lateral deformations which would result in excessive total and differential settlements. This objective was achieved as indicated by the relatively small 40 mm lateral deformations which were associated with up to 300 mm of vertical settlement. Settlement profiles across the tanks were also very uniform. The effective stress path yield envelope approach was also used to explain the significant...

Chemical formulation for soil stabilization and fugitive dust control

Abstract: Concentrates and compositions useful for enhancing the geotechnical properties of soil materials so as to control soil erosion and fugitive dust in both quiescent areas and road beds comprise, in admixture, homo- or co-polymers of acrylic acids or salts thereof, polybasic acids or salts thereof, water, and optionally a wetting agent.

Soil Compliance Influence on Tyre Performance

Abstract: : It is not uncommon in off-road mobility for vehicles to operate over varying types of terrain In situations where inorganic clay soils constitute the primary substrate material, considerable differences in soil stability and compliance characteristics can occur because of local variations in soil type, density and water content This study takes into account the above constraints in the methodology developed for evaluation and prediction of efficient tyre performance This requirement for capability in development of efficient tyre traction on soil for mobility purposes is critical if off-road operations are performed in remote regions where minimum fuel expenditure is particularly important The developed analytical procedure utilizes the experience gained from experimental tow-bin tests which studied tyre-soil interaction under varying tyre and soil conditions

Metallic powders in reinforced earth

Abstract: The effect and the possible performance of soil-metallic powders reinforcement systems are evaluated. A series of undrained triaxial compression tests were carried out on cylindrical samples of silty clay reinforced with metallic powders (aluminum and cast iron) at various percentages by weight of the soil. The inclusion of metallic powder in earth improved both the strength and deformation behavior of soil substantially. The addition of small amounts of metallic powder significantly increased the maximum principal stress difference of soil sample. The metallic powder imparted additional cohesion to the soil to a significant extent.

Shear Strength Development in Expansive Soil with and without CNS Surcharge

Abstract: Shear strength development in expansive soil under various thicknesses of Cohesive Non-Swelling Soil surcharge is studied in large scale devices. An attempt is made to develop methods using conventional shear strength testing devices to evaluate appropriate shear parameters specially for expansive soil which is prevented from swelling under adequate thickness of cohesive Non-Swelling Soil Layer.

Instrumentation Performance in Soft Clay Soils (A Case History)

Abstract: In 1978, IDEAL BASIC INDUSTRIES, INC. initiated construction of a cement manufacturing plant located south of Mobile, Alabama on the Theodore Ship Channel. Because deltaic clays were too weak to support the limestone stockpile, provisions were made to improve in-situ soil strength by surcharging using stage loading techniques. Vertical wick drains were installed to accelerate consolidation. In-situ soil displacement and stability characteristics were predicted using laboratory testing to evaluate stress history, consolidation characteristics and stress-strain-strength properties of foundation clays.

Investigation of Leachability of Subbituminous Fly Ash Enhanced Road Base Materials

Abstract: Enormous amounts of coal fly ash produced by the utilities industry create a significant disposal problem. The abundance of fly ash along with its self-hardening properties led the Louisiana Department of Transportation and Development (LA DOTD) to use fly ash as a soil stabilizer for road bases. However, the LA DOTD is primarily concerned with the strength of the material and has not studied its leaching characteristics. In this study, a total of three samples, a 30 percent subbituminous fly ash/soil mixture, subbituminous fly ash, and soil, were leached following the EPA multiple extraction procedure and analyzed by Inductively Coupled Argon Plasma Spectrometry (ICAP). Results indicate that little change in leachate quality of subbituminous fly ash was caused by the soil stabilization process. The insignificant change is attributed to the low cation exchange capacity of the soil. ICAP analysis revealed that levels of toxic metals in the leachates are well within RCRA standards.

Roadbed Stabilization by Lime Slurry Injection Process

Abstract: This paper reviews the use of high pressure lime slurry injection for deep insitu stabilization to aid in the control of expansive clay soils below the surface of paved roadways. Two case histories are presented on this process, which is utilized to stabilize an existing paved road, prior to maintenance and to stabilize the subgrade of a proposed urban street, prior to its construction.

Soil stabilisation in Australia

Abstract: This paper provides a background to soil stabilisation practice and theory. It then reviews the Australian Road Research Board research contribution to the topic and also the contributions of other researchers. Finally, the various construction/ design approaches to stabilisation are reviewed and four guidelines are given to stabilisation practice. A number of valuable references are appended to the paper (a).

Soil stabilization work

Abstract: PURPOSE:To improve soft ground by a method in which a watr-permeable container housed with a lime- or cement-based soil stabilizer is penetrated or laid in the ground, and it is allowed to stand as such or mixed with the ground. CONSTITUTION:A lime- or cement-based soil stabilizer is packed into a container 1 made of one of water-permeable papers, chemical fibers of thermoplastic resins (e.g., Vinylon, etc.) which are liable to be softened and broken by the heat of reaction between lime and water and the expansion force, or natural fibers such as cotton, etc., in order to form a pack lime P. The pack lime P is penetrated into the ground S vertically or at an adequate angle and then mixed with the ground S with stirring as needed. When the container 1 made of paper or thermoplastic resin is used, the container 1 is broken by the expansion of the quick lime, and the moisture of the ground is absorbed, whereby reducing the moisture of the surrounding ground.

Stabilization of oklahoma shales-field implementation phases

Abstract: The improvement of U.S. 77 north of Ponca City, Oklahoma, into a four-lane divided highway involves the use of expansive clay as a subgrade material. To stabilize it, Portland cement, fly ash, lime and their conjunctive use were deemed necessary. Prior to field implementation, laboratory studies were conducted which showed that stabilization reduced the plasticity index substantially. The general amelioration of the shale subgrade is reflected in strength improvement after wet-dry cycles and the upgrading of the shear strength parameters of cohesion and angle of internal friction. The strength of short beams was correlated to unconfined compressive strength. The employment of the flexural and compressive moduli of elasticity is presented as an example of assessing pavement strength versus stresses induced by traffic. Data from X-ray diffractograms ascertain that the activity of the clay minerals in the raw shale is reduced as new crystals of hydrated and unhydrated calcium alumina and calcium silicate are formed. In addition, SEM observations depict these crystals and show that the void area is reduced thus rendering a more densified fabric. (Author)

Quality Control in Soil Compaction by Behaviours of Exciter

Abstract: : Soil compaction is one of the most effective methods for soil stabilization and is performed in most earthworks of earth dams and road embankments, etc. However, because its quality control depends upon tests performed at only several points in the fields to estimate such factors as the dry density, water content and C.B.R., misjudgement can occur when judging the degree of soil compaction required.