Soil Stabilization is the process to improve Soil Strength, Physical properties of soil i order to improve strength and durability. Soil stabilization is mainly aims at improving soil strength and increasing resistance to softening by water through bonding the soil particles together, water proofing the particles or combination of the two. Soil stabilization means the improvement of the stability or bearing capacity of soil. Soil stabilization can be accomplished by several methods. All these methods fall into two broad categories. Mechanical stabilization and Chemical Stabilization is one of the primary conditions.
What is Soil Stabilization ? Types Methods Process
Soil Stabilization process can be achieved through physical process by altering the physical nature of native soil particles by either induced vibration or compaction. altering soil properties by changing the gradation through mixing with other soils by mechanical methods. densifying the soils using compaction efforts, or undercutting the existing soils and replacing them with granular material. Mechanical solutions involve physically changing the property of the soil somehow, in order to affect its gradation, solidity, and other characteristics.
Types of Stabilization Methods
- Cement Stabilization
- Lime Stabilization
- Mechanical Stabilization
- Chemical Stabilization
- Bituminous Stabilization
- Grouting Stabilization
- Geo Textile Stabilization
- Reinforced Earth Stabilization
On stabilization under chemical reactions soil stabilization depends mainly on chemical reactions between stabilizer (cementitious material) and soil minerals (pozzolanic materials) to achieve the desired effect. Mechanical soil stabilization means blending different soil types to improve stability and strength. Some soils have weak engineering properties and same some have good properties. The transformation of soil index properties by adding chemicals such as cement, fly ash, lime, or a combination of these, often alter the physical and chemical properties of the soil including the cementation of the soil particles to increase durability.
There are a number of different types of soil stabilization that rely on chemical additives of one sort or another, combination of chemicals, you will frequently encounter compounds that utilize cement, lime, fly ash, or kiln dust. The stability of soil-aggregate mixtures depends on the mechanical strength of aggregate, the mineral composition of the materials, the mixture gradation, the plasticity of the binder soil and the performed compaction. Stabilization can be used to treat a wide range of sub-grade materials, varying from expansive clays to granular materials.
on chemical stabilization method, sodium sulphate and sodium carbonate have an adverse effect on the stability due to their high volume changes caused by water content variations, while chlorides and carbonates contribute to soil stability. accomplished using a wide variety of additives, including lime, fly-ash, and Portland cement. Other material byproducts used in Stabilization include lime-kiln dust (LKD) and cement-kiln dust (CKD). Soil stabilization involves the use of stabilizing agents in weak soils to improve its geotechnical properties such as compressibility, strength, permeability and durability. The components of stabilization technology include soils and or soil minerals and stabilizing agent or binders
Through soil stabilization, unbound materials can be stabilized with cementitious materials (cement, lime, fly ash, bitumen or combination of these). The stabilized soil materials have a higher strength, lower permeability and lower compressibility than the native soil. Sodium silicate is yet another chemical used for this purpose in combination with other chemicals such as calcium chloride, polymers, chrome lignin, alkyl chlorosilanes, siliconites, amines and quarternary ammonium salts, sodium hexametaphosphate, phosphoric acid combined with a wetting agent.
Chemical Stabilization followed by two way
1) in situ stabilization
2) ex situ stabilization
Type of stabilization is purely depends upon which soil propertties have to be modified. Intrest to engineers are volume stability, strength, compressibility, permeability and durability.
The method involves on site soil improvement by applying stabilizing agent without
removing the bulk soil. This technology offer benefit of improving soils for deep
foundations, shallow foundations and contaminated sites. Planning of the design mix
involves the selection and assessment of engineering properties of stabilized soil and
The technology involves dislodging of the soils and or sediments from the original position and moves to other place for the purpose of amendment. These can be encountered in dredging of river channel and Ports. The main objectives of dredging can be either for amending the contaminated sediments to reduce toxicity and mobility or to maintain or deepen navigation channels for the safe passage of ships and boats
Hydrated lime (Ca(OH)2) Chemical Stabilition Model. it improve the strength, stiffness and durability of fine-grained soils. It can also be used as a soil stabilizer in the base course of concrete pavement. When it comes to mineral composition, sodium sulphate and sodium carbonate have an adverse effect on the stability due to their high volume changes caused by water content variations, while chlorides and carbonates contribute to soil stability.
Uses of Soil Stabilization
- By Soil Stabilization methods increase the unit weight of the soil
- It is also used to make an area trafficable with less time for emergncy purpose uses.
- It is used to increase the foundation soil bearing capacity
- Stabilization increases the shear strength of soil
- it helps to decrease the void ratio of the soil
- Soil Stabilization is used to reduce the permeability and compressibility of the soil mass in earth structures and to increase its shear strength.
Advantages of Soil Stabilization:
Higher resistance (R) values
Elimination of excavation, exporting unsuitable material and importing new materials
Provides “all-weather” access onto and within project sites
Reduction in plasticity material
Aids compaction easy
Lower permeability Services
Reduction of pavement thickness
Disadvantages of Soil Stabilization:
high cost and high carbon footprint,
highly demanding in equipment, labour and time, and thus represents significant traffic disruption.
Electrical stabilization of clayey soils is done by method known as electro-osmosis. This is an expensive method of soil stabilization and is mainly used for drainage of cohesive soils.
Stabilized Factors Affecting The strength of soil, Presence of organic matters, sulphates, sulphides and carbon dioxide in the stabilized soils may contribute to undesirable strength of stabilized materials