Typical values of Young's moduli (in GPa) for nine common rock types (after Johnson and Degraff, 1988). Linearity in the material behavior in uniaxial compression will also be reflected in its response to pure shear and hydrostatic compression.

Reliable estimates of the strength and deformation characteristics of rock masses are required for almost any form of analysis used for the design of slopes, foundations and underground excavations.

Shear strength laboratory testing methods are described in Section 200D-1. The selection of peak, fully softened, or residual shear strength for design analyses should be based on review of the expected or tolerable displacements of the soil.

In general, compared to intact rock, a rock mass has reduced tensile strength (almost zero), and reduced shear strength especially along discontinuity planes. Furthermore, if a rock mass is cut by directional joint sets, the rock mass strength is anisotropic.

The summary includes location and geologic occurrence and a petrographic description of the rock types. Properties listed include: absorption; specific gravity; secant elastic modulus; compressive strength; tensile strength; and shear strength, including cohesion and coefficient of angle of internal friction.

Characterization of the small-strain shear modulus and the shear wave velocity of soils and rocks is an integral component of various seismic analyses, including site classification, hazard analysis, site response analysis, and soil–structure interaction.

In materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of shear stress to the shear strain: The following chart gives typical values for the shear modulus of rigidity. All data can be recalculated and the is a unit convertsion calculator for unique materials.

The shear modulus is the ratio the shear stress needed to deform a material by a given angle (measured as the tangent of the deformation angle). As strain has

the dynamic Young's modulus, Ed, Poisson's ratio νd, and shear modulus Gd are calculated from the measured shear and longitudinal wave velocities V s and V p (about 1.5 V s ) as follows where γ is the unit weight of the rock and g is the acceleration due to gravity.

Rock Stiffness, Deformation To solve a σ′-ε problem, we must know how the rock deforms (strain -ε) in response to ∆σ′ This is often referred to as the “stiffness ” (or compliance, or elasticity, or compressibility…) For “linear elastic ” rock, only two parameters are needed: Young’s modulus, E, …

Feb 13, 2015 · Value of modulus of elasticity can be determined by static or dynamic methods. Higher value of modulus of elasticity indicates good quality rock having sound composition. Typical values of modulus of elasticity of some common are given in the table below.

Mar 20, 2025 · (2) Shear modulus (μ) is the ratio of the applied stress to the distortion (rotation) of a plane originally perpendicular to the applied shear stress; it is also termed the modulus of rigidity. (3) Bulk modulus (k) is the ratio of the confining pressure to the fractional reduction of volume in response to the applied hydrostatic pressure.

Determining the appropriate strength parameters are important as the design should be in accordance with the type of structures, loading characteristics and characteristics of rocks in the bearing strata.

From uniaxial compression test, young's modulus of elasticity and Poisson's ratio of rock specimen are determined if the stress strain behaviour till peak is captured. The slope of the stress-strain curve is basically gives the elastic modulus of the specimen.

seismic measurements are made under elastic, low-strain conditions. In the case of a simple elastic material, where non-destructive, low-strain is implicitly assumed, the seismic shear modulus (Gmax) provides an upper-bound measurement of strength and is …

Sep 11, 2020 · Rigid rocks with a high value of Young's modulus will result in narrower fractures than rocks with a lower rigidity. The shear modulus, µ (Pa) or G describes the rigidity of a material, its resistance to shear strain/angular distortions. Note that fluids have a shear modulus of zero as they cannot withstand any shear stress.

Two charts of compressional moduli (M) and AIp versus porosity in Fig. 18c-d confirmed that both M and AIp of MMF30 are underestimated by the soft sand model, while overestimated by the stiff...

porosity range: rock is in the consolidated, frame-supporting state in the domain from zero to the critical porosity, and is in the suspension, fluid-supporting state in the domain from the critical porosity to 100%.

Jun 24, 2010 · Lamé parameter (λ) and shear modulus (μ) are the most important, intrinsic, elastic properties of rocks. The Lamé parameter λ, which relates stresses and strains in perpendicular directions, is close...

Mar 21, 2025 · Table 2 outlines the rock types analyzed, their geometrical forms, and the conducted measurements. ... The shear modulus of the crack-free solid was calculated to be 28 GPa using the mineral volume ratio of medium-grained Chinese biotite granite and the elastic moduli of each mineral. We found that rapid decompression reduced the shear modulus ...

Jan 29, 2025 · Fig. 1 – Types of stresses: (a) pressure, (b) tensile, (c) general with normal and tangential components, and (d) shearing stress (modified from Hubbert [1]). Fig. 2– Stresses acting on the elemental cube. The stresses must be balanced so that there is …

4 days ago · Data collection. Rock mechanics tests on granites from Qingdao, Shandong Province, China, serve as prototypes. Granites were drilled as cylindrical specimens (diameter 50 mm × height 100 mm) and ...

2 days ago · The internal friction angle, tensile strength, and compressive strength are critical mechanical parameters that characterize a rock's resistance to shear and tensile failure. Changes in the differential strength parameters between the gravel and matrix directly affect the failure modes, crack propagation directions, and structural stability of ...

6 days ago · The excavation process for a deeply buried chamber in a high ground stress area is often dynamic. The design of reasonable excavation methods for differing geological conditions and surrounding pressure environments is of great engineering significance in order to improve the stability of surrounding rocks during construction. Based on the findings from conventional …

2 days ago · The crack initiation stress (σci) and crack damage stress (σcd) are two important stress thresholds for describing the progressive failure process of rocks. Accurately obtaining these two stress thresholds is crucial for analyzing the anisotropic characteristics of shale under the influence of bedding planes. The stress thresholds of rocks can be effectively obtained …