Lecture 1 Flashcards
What is a geotechnical structure?
Interaction between the ground and construction. Requires the analysis of the geotechnical structures to ensure stability and acceptable deformation.
What are some examples of geotechnical structures?
- Shallow foundations
- Pile foundations
- Slope Stability
- Retaining walls
Draw out the Geotechnical Triangle
What engineering properties of soil do we need to know for construction?
Support
- Strength (Cohesion, Friction Angle, unconfined compressive strength, CBR)
- Stiffness (Youngs modulus, Shear modulus)
Deformation
- Volume change
- Bulk Modulus
- Consolidation
- Creep
- Heave
Definition of Cohesion
Clay type soils which hold molecules together within a soil.
Definition of Friction Angle
Helps to quantify a soils shear strength
Definition of Shear Modulus
Earths material response to shear deformation
Definition of unconfined compressive strength?
The max axial compressive stress that a specimen can bare.
Definition of Bulk modulus?
change in the volume of a body produced by compressive or tensile stress acting uniformly over its surface.
Definition of Consolidation
Process which reduction in volume takes place by gradual absorption of water under long term loads.
Definition of creep
materials accumulate strains under the influence of constant stresses.
Definition of heave
soil beneath a load expanding.
What materials of a soil can influence its properties?
- Plasticity
- Grain shape/angularity
- particle size/grading
- minerology
- water content
- density
Definition of Plasticity?
Ability of a material to undergo permanent deformation under stress without cracking.
