Several factors influence the technique of soil improvement that you can use, including the equipment that is available and cost. One of the most important elements that might impact the decision to use one soil improvement approach over another is the type of soil.
Soil improvement is necessary in some instances to avoid liquefaction and provide appropriate bearing capacity to the foundation. The following are some of the more common soil enhancement strategies.
1. Deep compaction of soil
This is a method that uses severe impact, vibration, and blasting to densify cohesive soil deposits in-situ. It involves the transformation of a loose cohesionless soil structure into a dense one so that it can support a bigger weight load.
2. Grouting and injection
Grouting is one of the methods for controlling groundwater during civil engineering projects. It is the injection of pumpable materials into a soil or rock formation to modify its physical qualities. This method is appropriate when soil permeability would place a high demand on pumping or where subsurface conditions would make drilling wells economically inefficient.
Alternatively, chemical grouting is also possible – this is a method of permeating pore spaces in granular soils with low viscosity, non-particulate grout that hardens to form a cemented mass.
3. Pre-compression
Pre-compression is a ground improvement technique in which the ground is compressed under pressure before the structural load is placed or finished. Pre-loading comprises adding and removing earth, water, or another dead load comparable in weight to the ultimate load before construction, achieving ground pre-compression.
4. Soil improvement with additives
Using admixtures such as lime, cement, and a cohesive-non-swelling (CNS) layer, any one or more of the soil qualities can be modified to increase soil strength and minimise shrink-swell characteristics.
5. Thermostatic soil improvement
There are two approaches for improving the soil with thermal processes, either by heating or cooling the soil. Removing heat from the soil and freezing its pore water is a potent approach for making the ground impermeable and more resilient for unconsolidated materials.
Alternatively, using heat to force out free pore water and, at higher degrees, water adsorbed on particle surfaces makes a strong, lasting material, such as bricks or mud construction blocks.
6. Consolidation
Reinforced soil reinforcement is a technique that uses technologies including reinforced soil, soil nailing, root or micro-piles, slope dowels, and embankment piles to enhance the stiffness and strength of the soil.
7. Importance of drainage
The risk of liquefaction can be lowered by improving the soil\’s drainage capacity. The build-up of excess pore water pressure will be decreased if porewater within the soil can drain easily.
Installation of drains made of gravel, sand, or synthetic materials is one method of drainage. In contrast to gravel or sand drains, which are typically laid vertically, synthetic wick drains can be positioned at various angles.
Why it’s important
There are many reasons why it is important to use correct solid improvement methods in the right circumstances, such as the previously mentioned stability in foundation construction, but there are many other reasons to invest time and thought into soil improvement before construction.
Soils capture and store carbon, lowering greenhouse gas emissions (GHG) in the atmosphere, and hence aid in the fight against and adaptation to climate change. Additionally, water can infiltrate into resilient soils, screening pollutants and preventing them from seeping into groundwater.
Ultimately, ensuring that your soil is secure and safe from liquefaction is a fundamentally important factor when starting any project.
Get in touch with our team of expert piling contractors to discuss your requirements and find the best soil improvement method for your project.