Young's Modulus of Soil

This current tool estimates the modulus of elasticity or Young's modulus of soil based on theoretical correlations with N SPT number. Correlations available on this tool are mainly based on recommendations from the Foundation Analysis and Design book from Bowles (5th Edition, 1997). The tool also allows for estimating Young's modulus as an average value from multiple correlations (ie. selecting correlations for gravelly sand and saturated sand and averaging between the two).

Young's Modulus of Soft Rock

The current tool estimates the deformation modulus or modulus of elasticity of soft rock based on Hoobs (1974) mass factor theoretical equation. It requires as an input the unconfined compressive strength of rock from UCS laboratory tests and RQD values from coring. The equation also requires an estimate of the modulus ratio value, Mr, to account for rock type.

Based on RQD, the equation calculates the mass factor j, to account for rock mass discontinuities, fractures, and weathering and the modulus ratio value, M, to account for rock type.