Lime injection technique to improve the behaviour of soft marine clays

Lime Stabilization Technique for the Improvement of Marine Clay.

Abstract: Marine clays are present in many parts of the world and these deposits are characterized by poor engineering properties such as low strength and high compressibility. These deposits are sensitive to changes in the stress system and the system chemistry of the pore fluid, and the use of a lime stabilization technique for such problematic clays is not new. In the present investigation an attempt was made to examine the diffusion of lime in the lime treated marine clay from the lime column or lime injection points and the changes which occurred in the engineering behavior of the soil system. The formation of new reaction products due to soil-lime reactions has resulted in particle growth of soil particles and the same has been confirmed using scanning electron microscopy. The test results indicated that the presence of excessive sodium ions in sea water do not retard the effective penetration of lime into the soil and that there is significant improvement in the engineering behavior of the soil system. The lime column and lime injection techniques can therefore be conveniently used to improve the behavior of soft marine clay deposits.

Utilization of recycled tiles and tyres in stabilization of soils and production of construction materials – a state-of-the-art review

Abstract: Tile waste is found in several forms including manufacturing slurry, manufacturing dust, and solid pieces from cracked, smashed, and rejected tiles at the construction sites. Worn out tyres that are no longer safe to be used by vehicles are either discarded or burned, adversely impacting natural ecosystems. These wastes are non-degradable and have a direct environmental impact. Poor waste management can lead to hazardous pollution, reduced soil fertility, and increased space consumption at disposal sites. The massive and increasing volume of the tile and tyre wastes calls for recycling of the materials for economical reuse, cleaner production, and greener development. One area for beneficial reuse of these waste materials is the improvement of engineering properties in soft soil. Structures on soft soils may experience several forms of damage due to insufficient bearing capacity and excessive settlement. Hence, soil stabilization is often necessary to ensure that the soft soil can meet the engineering requirements for stability. A comprehensive review of the published literature on the use of recycled tyres and tiles to stabilize and enhance soft soils was carried out. The properties of soft soil-waste mixtures such as liquid limit, plastic limit, plasticity index, compaction behaviour, unconfined compressive strength, and California Bearing Ratio have been presented. When used as partial replacement of cement, sand, and aggregate in concrete, the effect of tyre and tile waste on workability, durability, and compressive strength of the concrete has also been presented. Recycled tiles and tyres have been used with or without any other admixtures to sustainably improve the strength and bearing capacity of soil. The suitability of recycled tiles and tyres in soil stabilization has been discussed with regard to enhancement of strength and reduction of settlement. In addition, the beneficial effects of the recycled tiles and tyres, when they partially replace cement, sand or stone in concrete, have been discussed.

A laboratory study on strength loss in kaolin surrounding lime-cement columns.

Abstract: This study evaluated property changes in laboratory-prepared kaolin surrounding lime–cement columns. The parameters investigated included geotechnical parameters such as undisturbed undrained shear strength, remoulded shear strength, water content, and Atterberg limits. In addition the exchangeable Ca2+, Na+ and K+ ion concentrations were assessed. Four types of small-scale lime–cement columns were manufactured using different production methods and binder blending ratios. Tests were performed 7, 14, 30 and 90 days after installation. The migration of Ca2+, Na+ and K+ ions from the lime–cement columns into the surrounding soil has been confirmed through the chemical analysis on a large number of samples taken. The results illustrate that the undrained shear strength properties in the surrounding kaolin were significantly affected by the migration of Ca2+, Na+ and K+ ions. An increase in the Na+ and K+ ion concentrations in the front of the migrated Ca2+ ions was observed. The tests illustrate that, under the experimental conditions chosen, the remoulded undrained shear strength decreased in a thin zone as a result of the migrated Na+ and K+ ions. The magnitude of the strength loss depended on the binder blending ratio in the lime–cement columns.

A new landfill liner to reduce ground-water contamination from heavy metals

Abstract: A series of permeameters (columns) was used to evaluate the effects of the percolation of water and 1,000 {micro}g/mL of zinc chloride solution through a mixture of montmorillonite clay, sand, and lime. The column test results show that the addition of lime changes the chemical and physical properties of the clay. The hydraulic conductivities for the mixture of clay with different percentages of lime at first increases with increasing lime and then decreases with increasing lime. The breakthrough curves indicate that the Zn(II) capture is increased and Zn(II) breakthrough is delayed with increasing lime addition. Lime also enhances the clay/lime mixture`s ability to resist puncture by sharp objects. Based on the effects of lime on Zn(II) captured by the clay, an explanation for the interacting effects of lime and Zn(II) capture on changing hydraulic conductivity is suggested. The results of this research demonstrate the potential of using lime-treated clay liners for landfills. Such liners would have lower hydraulic conductivity, better resistance to puncture, and enhanced ability to capture heavy metals.

Mitigation against lateral buckling and axial walking of subsea pipelines

Abstract: There is a growing concern amongst offshore pipeline operators over the instability problem of lateral buckling and axial walking of offshore pipelines which is linked with elevated operating temperature and pressure While some mitigating options are available to tackle this phenomenon, in most cases these are expensive and impracticable in deep waters, and none ofthem involves the modification of the ambient soil properties typically characterised by very low undrained shear strength (Cu) and high water content (w) In recent times, the use of engineered buckle solutions has become generally accepted as a cost effective and elegant solution This option involves laying the pipeline in a snake configuration where some specific sections are designed to move during operation while others relatively stable This option depends on accurate understanding of pipe-soil interactions which presently poses the greatest uncertainty in pipeline design Furthermore, in order to ensure that the buckles are formed as predetermined, the ambient soil strength must be sufficient to resist the pipe motion at locations designed to be relatively stable or the entire design approach would be undermined This dissertation presents laboratory investigations at both small and pilot scale directed at using the electro-kinetic phenomenon (EK) to treat the soil around a partially buried pipeline with the aim of increasing the pipeline stability to lateral buckling and axial walking The influence of the EK treatment was assessed by evaluating the changes in the soil Cu, wand the soil resistance to vertical, lateral and axial displacements of pipe sections Additionally, large-scale pipe-soil interaction studies were conducted to study the soil deformations, especially the real time study of the berm of soil formed and the development of the soil resistance during pipe motion Preliminary results of the application of EK in geotechnical engineering to offshore pipelines show up to 600% increase in Cu, 14% decrease in w and 190% increase in the pull out force thus implying promising outcomes which could form the basis for subsequent research in this area

Soil Chemical Analysis

Abstract: Soil chemical analysis , Soil chemical analysis , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Laboratory investigations on the lime stabilization of sensitive clays: shear strength development

Abstract: A laboratory investigation on the quicklime stabilization of sensitive clays has shown that, even at a water content above the liquid limit, significant strength increase can be obtained if enough ...

Reaction of hydrated lime with pure clay minerals in soil stabilization

Abstract: THE USE OF HYDRATED LIME HAS BEEN GROWING IN THE FIELD OF SOIL STABILIZATION ALTHOUGH IT HAS BEEN USED FROM COAST TO COAST IN THE UNITED STATES AND BY SOME NATIONS ABROAD, THE REACTION OF HYDRATED LIME WITH THE SOIL IS STILL A MYSTERY, PARTICULARLY WITH RESPECT TO ITS RELATIVE EFFECTIVENESS AND RATES OF REACTION WITH VARIOUS SOILS A RESEARCH PROJECT TO DETERMINE THE REACTION OF HYDRATED LIME AND SOIL IS UNDER WAY AT THE UNIVERSITY OF ILLINOIS BECAUSE OF THE COMPLEXITY OF SOILS AND BECAUSE LIME IS OF GREATER BENEFIT TO A HEAVY CLAY SOIL, THE FIRST PART OF THE INVESTIGATION HAS BEEN DEVOTED TO A STUDY OF THE EFFECTS OF HYDRATED LIME ON PURE CLAY MINERALS BY THE AID OF X-RAY DIFFRACTION AND DIFFERENTIAL THERMAL ANALYSIS, IT HAS BEEN POSSIBLE TO WATCH AND IDENTIFY THE REACTIONS WHICH TAKE PLACE THE FIRST REACTION, WHICH IS BROUGHT ABOUT IMMEDIATELY WHEN LIME IS ADDED, IS REPLACEMENT OF ABSORBED IONS BY CALCIUM IONS, THE SECOND, FORMATION OF A SERIES OF NEW MINERALS, THE THIRD, CARBONATION OF THE HYDRATED LIME THESE REACTIONS, ILLUSTRATED BY TYPICAL X-RAY EXAMPLES, OFFER DEFINITE PROOF AS TO WHY DIFFERENT RATES OF REACTION OCCUR WITH DIFFERENT SOILS /AUTHOR/

Geology, mineralogy, and geochemistry of Canadian soft soils: a geotechnical perspective

Abstract: A review of the recent research literature concerning the geology, mineralogy, and physicochemistry of soft soils in Canada is presented. Soft clays are considered from three viewpoints: (1) their ...