The strength of a material is the greatest stress it can sustain The safety of any geotecchnical structure is dependent on the strength of the soil
Shear Strength:
The strength of a material is the greatest stress it can
sustain
The safety of any geotecchnical structure is dependent on the
strength of the soil
If the soil fails, the struc ture founded on it can collapse
Thus shear strength is 'The
capacity of a material to resist the internal and external forces
which slide past each other'
1 Significance of Sh ear Strength:
Engineers
must understand the nature of shearing resistance in order to analyze soil
stability problems such as;
Bearing
capacity Slope stability
Lateral
earth pressure o n earthretaining structures Pavement
Thus shear strength of soil is 'The capacity of a soil
to resist the internal and external forces which slide past
each other'
2 Shear Strength in Soils:
The shear strength of a s oil is its resistance to shearing
stresses.
It is a measure of the soil resistance to deformation by
continuous displacement of its individual soil particles.
Shear strength in soils depends primarily on interactions
between particles.
Shear failure occurs wh en the stresses between the particles
are such that they slide or roll past each other
3 Components of s hear strength of soils
Soil derives its shear strength from two sources:
 Cohesion
betwe en particles (stress independent component)
Cementation between sand grains
Electrostatic attraction between
clay particles

Frictional
resist ance and interlocking between particles (stress dependent
component)