Q1: Define soil.
Ans:The unconsolidated mineral material of earth crust is known as soil.
Q2: Define soil mechanics.
Ans:The branch of engineering science which enables an engineer to know the behaviour of soil under the action of Loads, water, temperature etc.
Q3: What are the constituents of soil?
Ans:
Soil consist of four layers:- Litter layer (Organic matter)
- Surface soil (Top soil with humus)
- Subsoil
- Bedrock (Parent rock)
Q4: Define clay soil.
Ans:The grain size of clay particles is less than 0.002 mm. It is composed of microscopic and sub microscopic particles of weathered rocks.
Q5: Define silt
Ans:It is a finer variety of soil having grain size varying from 0.002mm-0.06mm. It is found in the beds of rivers, canals etc.
Q6: Define organic matter.
Ans:The top most layer of soil is called organic matter or Litter layer.
Q7: Define vegetation soil.
Ans:Vegetative soil groups (VSG's) consist of soils having similar properties and qualities that affect their suitability for plant establishment and growth.
Q8: What is meant by surface soil?
Ans:It is the immediate uppermost loose layer of the earth consisting of organic matter and soil organisms suitable for plant growth.
Q9: Define sub-soil.
Ans:It is the layer of soil under the topsoil on the surface of the ground. Like topsoil it is composed of a variable mixture of small particles such as sand, silt and/or clay, but with a much lower percentage of organic matter and humus
Q10: What do you know about parent rocks?
Ans:It is the lowest layer containing unbroken rocks. It may contain more soluble compounds.
Q11: Define alluvial soil.
Ans:This soil is transported and is carried away by the forces of water. Solid particles get mixed up with soils of different origin.
Q12: Define types of weathering.
Ans:
Disintegration of rocks into various forms is known as weathering. It is classified as follows:- Physical Weathering
- Chemical Weathering
Q13: What is meant by compaction?
Ans:The process of increasing the density of a soil using force to pack the particles close together with a reduction in air voids without any significant change in the volume of water in the soil is known as compaction
Q14: Define consolidation.
Ans:Consolidation is a process which involves decrease in water content of a saturated soil without replacement of water by air.
Q15: Define permeability.
Ans:The ability of water to flow through a soil is referred to as the soil's permeability.
Q16: Define porosity.
Ans:Soil porosity refers to the amount of pores, or open space, between soil particles. A high porous soil has more spaces between the particles.
Q17: Define seepage.
Ans:The movement of water through soil into the structures is usually termed as seepage.
Q18: Differentiate between compaction and consolidation.
Ans:Check Answer # 13 and 14
Q19: What are the most suitable types of soil as a backfill for the under floor?
Ans:Coarse-grained soils, such as gravel and crushed stone, are commonly used as backfill materials.
Q20: Define bearing capacity of soil.
Ans:The maximum load which the soil can take per unit area without yielding or displacement is called ultimate bearing capacity of soil.
Q21: Name the factors affecting the bearing capacity of soil.
Ans:
Following factors directly or indirectly affect the bearing capacity of soil:- Type of soil
- Initial stress condition of soil
- Location of ground water in the soil
- Type of foundation
- Depth & location of foundation.
- Earthquake, floods, heavy winds etc.
