Static shear strength properties

Standard geotechnical test reports address typical static properties of soil such as shear strength and bearing capacity but may not provide dynamic properties unless they are specifically requested. In these situations, it is necessary to use the static properties. Dynamic soil properties which are reported may be based on low strain amplitude tests which may or may not be applicable to the situation of interest. Soils reports will generally provide vertical and lateral stiffness values for the foundation type recommended. These can be used along with ultimate bearing capacities to perform a dynamic response calculation of the foundation for the applied blast load. 

When a solid is subjected to a shearing force, the solid (simultaneously with the application of force) deforms, and internal stresses develop until a condition of static equilibrium is reached. Within the elastic limit of a substance, these internal stresses are proportional to the induced shearing strains (deformation). The ability of a material to reach static equilibrium, rather than deform continuously, is due to a property called shear strength. 

With a temperature change the short-term static strength, the elastic modulus, and the elongation behavior of a material will be similar for it s tensile, compressive, flexural, and shear properties. A... 

The in-plane mechanical, viscoelastic and thermal properties of a satin weave carbon fabric impregnated with an amine cured epoxy resin were studied by Abot and co-workers [74]. The in-plane quasi-static behaviour including the failure modes under tension, compression and shear and all the mechanical properties including elastic moduli and strengths were determined. The viscoelastic properties including the glass transition temperature were also measured as well as the coefficients of thermal expansion. These measured properties for the fabric composites were also compared with their corresponding ones for a unidirectional composite with the same fibre and matrix. 

Some tests, while imdergoing deformation, are usually referred to as static, in that they are performed at slow speeds or low cycles. Examples of these tests are stretch modulus, ultimate tensile strength, and elongation to break, ie, a measure of total energy capabihties or rupture phenomena. Dynamic properties are measured by continuous cycles of varying deformation (tension, compression, or shear), at varying frequencies which can be set close to that which a component would experience in a tire. These properties are more correlative to many tire performance parameters. 

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