Particle shape and size influence soil engineering properties. Coarse-grained soil particles like sand and gravel are generally bulky in shape with approximately equal length, width, and thickness. Particle shape depends on factors like rock type, age, weathering, and transportation processes, which cause edges to break and particles to become more rounded over time. Angular and rough particles have better engineering properties than rounded smooth particles. Flaky and elongated particles can bridge spaces and resist overburden pressure. Silt particles are bulky while clay particles are flaky with greater length and width than thickness, causing clay soil behavior to change drastically with moisture content. Clay particles are very small, less than 0.002mm, and their cohesive and plastic

1. PARTICLE SHAPE AND SIZE
Presented by: Muhammad Baig

2. PARTICLE SHAPE AND SIZE
 Particle shape and size very much influence
the engineering properties of soil.
 particles of course grained soil (sand ,
gravel ,boulder etc.)are generally bulky in
shape i.e., their length ,width and thickness
are approximately equal.

3. PARTICLE SHAPE AND SIZE
 Different shape are commonly termed as:
 Angular
 Sub-angular
 Sub rounded
 rounded

4. PARTICLE SHAPE AND SIZE

5. PARTICLE SHAPE AND SIZE
 The shapes of the particles however depend
on the:
 Rock type
 Their age
 Weathering
 Transportation process.
with the passage of time and as a
result of weathering and transportation
processes, the edges are broken and the
particle change finally to rounded shape.

6. PARTICLE SHAPE AND SIZE

7. PARTICLE SHAPE AND SIZE
 The angular and rough surfaced particles
possess better engineering properties
compared with those of rounded and smooth
particles.
 The flaky & elongated particles bridge over
open spaces, which can resist over burden
pressure.

8. PARTICLE SHAPE AND SIZE

9. PARTICLE SHAPE AND SIZE
 The silt particles are bulky in shape.
 The clay particles flaky in shape. Their length
and width are many-many times greater then
thickness.
 As a result the behavior of clay soil
drastically change with change of moisture
content .

10. PARTICLE SHAPE AND SIZE

11. PARTICLE SHAPE AND SIZE
 The clay particles are very small in size(less
then 0.002mm).
 The properties of clay (cohesion & plasticity )
are due to the type of mineral and not due to
it small size
 The particles of non-clay minerals although
smaller than 0.002mm.

12. THANKS