What is expansive soil and its characteristics?
Expansive soil is defined as partially saturated plastic soil that exhibits high volume change when its environmental conditions are altered from dry to wet. These soils, which lie above the water table, undergo shrinkage on drying and swelling on wetting.
What are the expansive soils?
Definition. Expansive Soils are soils that have the ability to shrink and/or swell, and thus change in volume, in relation to changes in their moisture content. The more water they absorb, the more their volume increases.
What does expansive soil look like?
Identifying Expansive Soil
Expansive soils are often clay like, becoming very sticky when wet and hard and brittle when dry.
What are the problems with expansive soils?
Because of this swelling and shrinking behaviour, expansive soils may cause the following problems in structures or construction projects: Structural damage to lightweight structures such as sidewalks and driveways. Lifting of buildings, damage to basements, and building settlement. breaks in walls and ceilings.
How is expansive soil treated?
Traditionally, ineffective & costly methods have been utilized in treating expansive soil. Methods such as removing it completely and replacing it with fill dirt, pre-wetting and pre-swelling the soil and injecting or mixing of lime or other solutions into existing soils.
What causes expansive soils?
Expansive soils are soils that expand when water is added, and shrink when they dry out. This continuous change in soil volume can cause homes built on this soil to move unevenly and break.
What are the major problematic soils?
The types are: 1. Acidic Soil 2. Alkaline Soil 3. Saline Soil.
What do you mean by problematic soils?
problematic soil The soil that causes additional problems from the engineering point of view as a result of the circumstances of its composition or a change in environmental conditions. Acidic Saline Sodic soil Alkaline Problematic soils (Chemical)
What are problems soils?
Problem soils can be defined as the soils on which most plants and crops cannot be grown economically and are not fertile or productive and there is the possibility of erosion hazard when cultivated. These soils need special soil–water–fertilizer–crop management practices to make them productive.
What do you understand by problematic soils?
Abstract. The soils which possess characteristics that make them uneconomical for the cultivation of crops without adopting proper reclamation measures are known as problem soils. Often we resort to chemical means of reclamation that leads to impairment of ecosystem functions.
Which one is the acid associated with soil?
Soils tend to become acidic as a result of: (1) rainwater leaching away basic ions (calcium, magnesium, potassium and sodium); (2) carbon dioxide from decomposing organic matter and root respiration dissolving in soil water to form a weak organic acid; (3) formation of strong organic and inorganic acids, such as nitric
What is the pH of saline soil?
The pH of saline soils is usually below 8.5. Because soluble salts help prevent dispersion of soil colloids, plant growth on saline soils is not generally constrained by poor infiltration, aggregate stability, or aeration.
How do you manage problematic soil?
They are problem soils. These soils need special management for satisfactory crop production. Physical limitations can be managed by irrigation, drainage, mulching, manuring, tillage, and soil conservation measures such as terracing, contouring, and cover crops whichever is appropriate.