1. What is Soil Shear Modulus?

The Soil Shear Modulus (G) is a measure of the soil's elastic shear stiffness. It represents the ratio of shear stress to shear strain in a material and is fundamental in geotechnical engineering for analyzing soil behavior under stress.

2. How Does the Calculator Work?

The calculator uses the Soil Shear Modulus equation:

Where:

• \( G \) — Soil shear modulus (Pa)
• \( \rho \) — Soil density (kg/m³)
• \( v_s \) — Shear wave velocity (m/s)

Explanation: The equation shows that shear modulus is directly proportional to soil density and the square of shear wave velocity through the soil.

3. Importance of Soil Shear Modulus

Details: The shear modulus is crucial for analyzing soil response to earthquakes, foundation design, slope stability analysis, and predicting ground motion during seismic events.

4. Using the Calculator

Tips: Enter soil density in kg/m³ and shear wave velocity in m/s. Both values must be positive numbers for valid calculation.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for soil shear modulus?
A: Values range from about 10 MPa for soft soils to several GPa for stiff soils and rock. It varies significantly with soil type and conditions.

Q2: How is shear wave velocity measured?
A: Common methods include cross-hole, down-hole, and surface wave tests (SASW or MASW) using geophones or accelerometers.

Q3: Does shear modulus change with stress level?
A: Yes, G typically increases with confining pressure and is strain-dependent, decreasing at higher strain levels.

Q4: What's the relationship between G and other elastic moduli?
A: For isotropic materials, G = E/[2(1+ν)] where E is Young's modulus and ν is Poisson's ratio.

Q5: When is this equation not applicable?
A: The simple equation may not account for anisotropic conditions, large strains, or partially saturated soils where more complex models are needed.