Mechanical Analysis of Soil
Geotechnical engineering studies rock and soil
supporting civil engineering systems.
Knowledge from the field of soil science, materials
science, mechanics, and hydraulics is applied to safely
and economically design foundations, retaining walls, and
other structures.
Identification of soil properties presents challenges to
geotechnical engineers.
Unlike steel or concrete, the material properties and
behavior of soil are difficult to predict due to its variabilit y
and limitation on investigation.
Mechanical Analysis of Soil
As complex as it is, soil can be described simply.
It consists of four major components: air, water, organic
matter, and mineral matter.
Mechanical Analysis of Soil
The structure of soil determines its suitability for conc rete,
road subsurface, building foundation, or filter media.
Soil has four constituent parts:
Sand is any soil particle larger than 0.06 millimeters (0.002
inches).
Silt is any soil particle from 0.002 - 0.06 millimeters.
Clay is any soil particle below 0.002 millimeters, including
colloidal clay so small it does not settle out of suspension in
water.
Mechanical Analysis of Soil
Mechanical Analysis of Soil Mechanical Analysis of Soil
The percentage distribution of those parts determines soil
structure.
Mechanical analysis is the determination of the size range
of particles present in a soil, expressed as a percentage of
the total dry weight.
There are two methods generally used to find the partic le-
size distribution of soil:
(1) sieve analysis - for particle sizes larger than 0.075 mm
in diameter, and
(2) hydrometer analysis - for particle sizes smaller
than 0.075 mm in diameter.
CIVL 1101
Introduction to Sieve Analysis
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