Cohesion: it is the force of attractioon between the particles binding them togeth er. cohesion is present in clays and silts but is n ormally absent in sands and gravels.Cohesio n (C), is a measure of the forces that cement particles of soils.
it is the force of attractioon between the particles binding them togeth er. cohesion is present in clays and silts but is n ormally absent in sands and gravels.Cohesio n (C), is a measure of the forces that cement particles of soils
Angle of Repose determ ined by:
· Particle size (hig her for large particles)
· Particle shape (higher for angular shapes)
· Shear strength (h igher for higher shear strength)
Gravity generates stresses (force per unit area) in the ground at different points. Stress on a plane at a given point is viewed in terms of two components:
1 Normal stress (?): acts normal to the plane and tend s to compress soil grains towards each oth er (volume change)
2Shear stress (?): a cts tangential to the plane and tends to slide grains relative to each other (distortion and ulti mately sliding failure)
3Factors Influenci ng Shear Strength:
The shearing strength is affected by:
· Soil composition: mineralogy, grain size and grain size distribution, shape of particles, pore fl uid type and content, ions on grain and in pore fluid.
· Initial state: State can be describe by terms such as: loose, dense, over-consolidated, no rmally consolidated, stiff, soft, etc.
· Structure: Refers to the arrangement of particles within the soil mass; the manner in whic h the particles are packed or distributed. Feaatures such as layers, voids, pockets, cementation, etc, are part of the structure.
4 Formulation of Shear Strength of Soil:
· In reality, a com plete shear strength formulation would acco unt for all previously stated factors.
Soil behavior is quite complex due to the possible variables s tated.