Rock Mass Properties Calculator

Rock Mass Properties Calculator is a specialized software designed to calculate rock mass strength parameters using the latest generalized Hoek–Brown failure criterion. It offers a straightforward and user-friendly approach, enabling users to accurately estimate rock mass properties and visualize how variations in these parameters influence failure envelopes. We will compare the results generated by our calculator with those from RocLab to assess its accuracy and functionality. See in the below the example in Figure 1 from Roclab which we will use for comparison.

**Figure 1 – Roclab Input and Output Results **

Hoek-Brown Input and Output Parameters

Input Parameters

Using the following Hoek-Brown failure criteria parameters as input:

1. the unconfined compressive strength of intact rock
2. the geological strength index GSI
3. the intact rock parameter mi and
4. the disturbance factor D

Table 1 - Input Parameters of Tunnel (Depth=342.4m)

Figure 2 -Schematic Diagram of Tunnel Below Ground Surface

Now we will use the same input values in RMP calculator, used in Roclab to see the results.

Figure 3 - Rock Mass Properties Calculator Input parameters After incorporating all the input parameters, we need to click to get the results.

Output Parameters

Table 3- Output Results of Tunnel from RocLab

Figure 4 - Rock Mass Properties Calculator Output Parameters

Display Capabilities: Instantaneous MC Sampler#

The Instantaneous Mohr–Coulomb Sampler feature enables users to visually extract cohesion and friction angle values at any point along the Hoek–Brown failure envelope.

Batch Calculator

Batch Calculator works on the same principle as in the Single Calculator. Batch Calculator with includes many sections along the tunnel alignment. Right now, you can add up to 50 rows. If you need more rows, please let us know.

All Reference Charts You will get below Educational Resources

Reference

1. Hoek-Brown failure criterion – 2002 Edition E. Hoek, C. Carranza-Torres and B. Corkum Proc. NARMS-TAC Conference, Toronto, 2002, 1, 267-273.
2. Hoek E. (2002). Practical Rock Engineering. London: Institution of Mining and Metallurgy. pp. 325.
3. Hoek E. and Brown E.T. (1980). "Empirical strength criterion for rock masses". J. Geotechnical Engineering Division ASCE: 1013–1025.
4. Hoek, E. and Brown (1988). "The Hoek-Brown failure criterion - a 1988 update". Proc. 15th Canadian Rock Mech. Symp.: 31-38. Hoek E, Carranza-Torres CT, Corkum B (2002). "Hoek-Brown failure criterion-2002 edition". Proceedings of the fifth North American rock mechanics symposium vol. 1: 267–273.