Question

Topic: Construction - Soil

1.) Create a 1-2 pages minimum technical report about the "Index Properties of Soils". Your report should include types and condition of soil, and provide their structural properties, compressibility, shear strength and compactness (relative density) characteristics.  

2.) Provide technical references from at least one source to support your points.

Answer 1

TECHNICAL REPORT ON "INDEX PROPERTIES OF SOIL" :-

1. Index properties are the properties of soil that helps in identification and classification of soils.These properties are generally determined in the laboratory.

Types :-

1.Water content - Oven drying method and calcium carbide method are two popular methods of determination of water content.

2.Specific gravity - Specific gravity of soils is determined by pycnometer method.

3.In-Situ density - This test is determined by core cutter method.

4.Particle size distribution - Soil in nature exists in different sizes,shapes,appearance.Depending on these attributes,the soil at a site can be packed either loosely or densely.Hence it is important to determine the percentage of various sized soil particles in soil mass.this process is called "Particle size distribution analysis".

5.Consistency limits - Liquid limit,plastic limit and shrinkage limit called as "Consistency limits"

6.Relative density

• Structural properties are same as the index properties of soil.They posses same properties like index properties of soil.Different types of soil posses different properties.
• Compressibility Characteristics :- Compressibility characteristics of soil forms one of the important soil parameters required in design considerations. Compressibility index,which is the slope of linear portion of void ratio vs logarithm of effective pressure relationship,extensively used for settlement determination.
• Shear strength Characteristics :- Shear strength parameters of soil defined as cohesion and friction angle.The shear strength of soil depends on effective stress,drainage conditions,density of the particles,rate of strain and direction of strain.
• Relative density Characteristics :- Depending upon the shape,size and gradation of soil grains,coarse grained soils can remain in two extreme states of compaction namely loosest and densest state.Any intermediate state of compaction can be compared to these two extreme states using an index called "Relative density or Density index".

2.Technical references :-

T.William Lambe and Robert V.Whitman chapter 3:"Description of an assemblage of particles:Soil mechanics" first edition