Strength Properties

In the Define Material Properties dialog, the Strength Parameters allow you to define:

• The failure (strength) criterion for a material
• The material type (elastic or plastic)

Failure Criterion

The following seven categories contain strength criteria and constitutive models available in RS2 for defining the strength of your rock mass or soil:

1. Elastic/Plastic

   The Elastic/Plastic category includes Mohr-Coulomb, Hoek-Brown, Drucker-Prager, Generalized Hoek-Brown, and Discrete Function strength criteria.

2. Softening/Hardening

   The Softening/Hardening category includes Cam-Clay, Modified Cam-Clay, Mohr-Coulomb With Cap, Softening Hardening Model, Barcelona Basic, and NorSand constitutive models.
   

3. Dynamic

   The Dynamic category includes Bounding Surface Plasticity, Manzari and Dafalias, PM4 Sand, PM4 Silt, and Finn constitutive models. An example of Bounding Surface Plasticity, Manzari and Dafalias, and Finn constitutive model applications is shown here: Finn Model-Verification Problem. PM4 Sand and PM4 Silt models can be found here.

4. Slide Models

   The Slide Models category includes Barton-Bandis, Hyperbolic, Power Curve, Shear/Normal Function, SHANSEP, and Vertical Stress Ratio strength criteria. The Slide Models manual can be found here: Slide- Isotropic Models.

5. Anisotropic

   The Anisotropic category includes Snowden Modified Anisotropic Linear, Anisotropic Linear, Generalized Anisotropic, Jointed Mohr Coulomb, and Jointed Generalized Hoek Brown strength criteria. Anisotropic model manual can be found here: Slide- Anisotropic Models.

6. FLAC

   The FLAC category includes ChSoil, CySoil, and Double Yield constitutive models.

7. PLAXIS

   The PLAXIS category includes Hardening Soil, Hardening Soil with Small Strain Stiffness, Soft Soil, Soft Soil Creep, and Swelling Rock constitutive models.

Material Type

You may select either Elastic or Plastic for the Material Type. This option is available for elastic-perfect-plastic and elastic-brittle-plastic models.

Link to RSData

If you have the program RSData installed on your computer, you can start up these programs directly from the Define Material Properties dialog. You can then use RSData to help determine parameters for the Mohr-Coulomb, Hoek-Brown or Generalized Hoek-Brown criteria (e.g. by curve fitting lab test data, for example).

• To start up RSData select the button in the Define Material Properties dialog. If you have both programs installed on your computer, then RSData will be opened.
• To paste applicable results from RSData into RS2, first select the Copy Data option in RSData, and then select the paste button in the Define Material Properties dialog in RS2. Applicable data will be pasted into the dialog. If applicable results for the selected strength criterion are not found, an error message will be displayed.

Additional information can be located in the Material Model Manuals:

1. Preliminaries on Constitutive Models
2. Elastic Models
3. Elastoplastic Constitutive Models
4. Druker-Prager Model
5. Mohr-Coulomb Model
6. Hoek-Brown Model
7. Duncan-Chang Model
8. Cam Clay and Modified Cam Clay Model
9. Jointed Rock Model
10. Mohr-Coulomb with Cap Model
11. Softening-Hardening Model
12. User Defined Material Model
13. ChSoil Model (FLAC)
14. CySoil and Double Yield Model (FLAC)
15. Hardening Soil Model (PLAXIS)
16. Hardening Soil Model with Small Strain Stiffness (PLAXIS)
17. Soft Soil Model (PLAXIS)
18. Soft Soil Creep Model (PLAXIS)
19. Swelling Rock Model (PLAXIS)
20. Slide- Isotropic Model
21. Slide- Anisotropic Model
22. Finn-Martin Model
23. Conversion of non-linear strength envelopes to Generalized Hoek-Brown Envelopes
24. PM4 Sand
    
25. PM4 Silt
    

For information about RSData see the Rocscience website.