Elastic Properties

In the Tunnel and Rock Parameters dialog, you must enter the following Elastic Properties for the rock:

• Young's Modulus
• Poisson's Ratio

These properties are always required, regardless of the Solution Method.

Estimation of Young's Modulus

Young's Modulus of the rock mass is often not a very well known quantity. If you do not know the value of this parameter, it can be estimated from empirical relationships based on rock mass classification schemes. RocSupport provides 3 different options for the Modulus Estimation Method, as selected in Project Settings.

See the Modulus Estimation Method topic for details.

Intact Rock Modulus

If you are using the Carranza-Torres Solution Method and the Generalized Hoek-Diederichs Modulus Estimation Method, you will be required to input the Intact Rock Modulus, rather than the Rock Mass Modulus. The Rock Mass Modulus is then estimated from the Intact Rock Modulus, GSI and D.