Table of ContentsWelcome to RocLab!................................................................2 Introduction..............................................................................3 Documentation.........................................................................4 How Can I Use RocLab?..........................................................5 Quick Tour of RocLab..............................................................7Entering Input Data...................................................................................7 Interactive Data Input.........................................................................7 Pick Dialogs........................................................................................7 Keyboard Entry...................................................................................8 Triaxial Lab Test Data........................................................................8 Estimating Input Parameters....................................................................9 Failure Envelope Plots............................................................................11 Right Click Menu..............................................................................12 Calculated Hoek-Brown Parameters......................................................12 Equivalent Mohr-Coulomb Parameters..................................................13 Failure Envelope Range...................................................................13 Other Rock Mass Parameters................................................................14 Triaxial Lab Test Data.............................................................................15 Example 1 Tunnel, undisturbed (D = 0)...............................................16 Example 2 Slope, disturbed (D = 1).....................................................18 Stress Sampler.......................................................................................20 Instantaneous Mohr-Coulomb Sampler..................................................21 Exporting Data / Images.........................................................................22 One Click Export to Excel................................................................22 Display Options.......................................................................................23 Mogis Line.......................................................................................23 Zoom Extents...................................................................................24

References..............................................................................25

Welcome to RocLab!RocLab is a software program for determining rock mass strength parameters, based on the generalized Hoek-Brown failure criterion. ffd8ffe000104a46494600010201009600960000ffe20c584943435f505 24f46494c4500010100000c484c696e6f021000006d6e7472524742205 8595a2007ce00020009000600310000616373704d5346540000000049 454320735247420000000000000000000000000000f6d600010000000 0d32d4850202000000000000000000000000000000000000000000000 000000000000000000000000000000000000000000000000001163707 274000001500000003364657363000001840000006c77747074000001 f000000014626b707400000204000000147258595a000002180000001 46758595a0000022c000000146258595a0000024000000014646d6e64 0000025400000070646d6464000002c400000088767565640000034c0 000008676696577000003d4000000246c756d69000003f8000000146d 6561730000040c0000002474656368000004300000000c72545243000 0043c0000080c675452430000043c0000080c625452430000043c0000 080c7465787400000000436f707972696768742028632920313939382 04865776c6574742d5061636b61726420436f6d70616e790000646573 630000000000000012735247422049454336313936362d322e3100000 0000000000000000012735247422049454336313936362d322e310000 00000000000000000000000000000000000000000000000000 RocLab is a product of Rocscience Inc. It is a free software program.

Rocscience produces many other software products for geotechnical, mining and civil engineering applications. Visit www.rocscience.com to find out about the many other software products available from Rocscience.

IntroductionOne of the major obstacles which is encountered in the field of numerical modeling for rock mechanics, is the problem of data input for rock mass properties. The usefulness of elaborate constitutive models, and powerful numerical analysis programs, is greatly limited, if the analyst does not have reliable input data for rock mass properties. The latest version of the Hoek-Brown failure criterion (Ref.1&2), in conjunction with its implementation in the software program RocLab, goes a long way toward remedying this situation. Some formerly troublesome issues with the failure criterion have now been resolved, including: the applicability of the criterion to very weak rock masses, and the calculation of equivalent Mohr-Coulomb parameters, from the Hoek-Brown failure envelope The program RocLab provides a simple and intuitive implementation of the Hoek-Brown failure criterion, allowing users to easily obtain reliable estimates of rock mass properties, and to visualize the effects of changing rock mass parameters, on the failure envelopes. The task of determining rock mass properties is not usually an end in itself. It is carried out in order to provide input for numerical analysis programs, which require material properties in order to perform a stability or stress analysis. The rock mass properties determined by RocLab can be used as input for numerical analysis programs such as Phase2 (finite element stress analysis and support design for excavations) or Slide (limit equilibrium slope stability analysis). Phase2 and Slide are also available from Rocscience.

DocumentationThe calculations in the RocLab program, are based on the latest version of the Generalized Hoek-Brown failure criterion, as detailed in the following papers (Ref. 1&2): Hoek, E., Carranza-Torres, C.T., and Corkum, B. (2002), HoekBrown failure criterion 2002 edition. Proc. North American Rock Mechanics Society meeting in Toronto in July 2002 Hoek, E and Diederichs, M.S. (2006), Empirical estimation of rock mass modulus. International Journal of Rock Mechanics and Mining Sciences, 43, 203215 The program RocLab incorporates all of the latest developments described in these papers. These papers should be read by all users of RocLab!!! The definitions and equations for all input and output parameters in RocLab, can be found in these papers, which are available as PDF documents. Access to these documents can be made through the RocLab Help menu or the RocLab Start Menu. Another useful document is the following (Ref. 3): A Brief History of the Hoek-Brown Failure Criterion, by Evert Hoek. This paper provides a brief chronological overview of the evolution of the Hoek-Brown failure criterion, and provides references to all of the significant papers which have been published. This is also recommended reading for all users of RocLab. The paper is also available as a PDF document. Finally, a set of notes by Dr. Evert Hoek, Practical Rock Engineering, (Ref. 4) is available on the Rocscience website, www.rocscience.com , in the form of a series of PDF documents. Practical Rock Engineering is recommended reading for all students of rock mechanics. Chapter 11 (Rock mass properties) should also be read by users of RocLab.

How Can I Use RocLab?The following tasks can be accomplished with RocLab.

Determine Strength Parameters Determine the Generalized Hoek-Brown strength parameters of a rock mass (mb, s and a), based on the following input data (see Ref 1): unconfined compressive strength of intact rock sigci the intact rock parameter mi the geological strength index GSI the disturbance factor D

Determine Rock Mass Deformation Modulus Determine the rock mass deformation modulus based on the following input data (See Generalized Hoek-Diederichs equation in Ref 2): the intact rock deformation modulus Ei Ei can be optionally estimated using a modulus ratio MR

Plot Failure Envelopes Plot the Hoek-Brown failure envelope in principal and / or shear-normal stress space. Interactively change sigci, GSI, mi, D, to see how the failure envelope changes with each parameter

Estimation of Input Parameters Each of the above 5 input parameters (sigci, mi, GSI, D and Ei), can be conveniently estimated from built-in charts and tables, based on rock type, geological conditions, etc. Triaxial Lab Test Data Triaxial lab tests on intact rock, can be used to determine sigci and mi using the Marquardt-Levenberg fitting technique. the triaxial data can be imported from Microsoft Excel through the clipboard, tab-delimited or comma separated value text files, RocData or other RocLab files. the data can also be entered in the program using a built-in spreadsheet.

Equivalent Mohr-Coulomb Parameters Calculation of equivalent Mohr-Coulomb strength parameters (cohesion

and friction angle).

The best-fit Mohr-Coulomb strength envelope is determined over a stress range that you can define based on your application (i.e. tunneling or slope stability). Plot the equivalent Mohr-Coulomb failure envelope in principal and / or shear-normal stress space

Stress Sampler Graphically sample the Hoek-Brown or Mohr-Coulomb failure envelope to determine strength for any discrete value of stress (principal, shear or normal stress). Instantaneous MC Sampler Graphically determine the instantaneous Mohr-Coulomb parameters at any point along the Hoek-Brown failure envelopes. Other Rock Mass Parameters The program also calculates rock-mass parameters such as tensile strength, uniaxial compressive strength and deformation modulus. Units A RocLab analysis can be carried out using either Metric or Imperial units. In Metric, the stress units are Megapascals (MPa). In Imperial, the stress units may be either Kilopounds per square foot (ksf) or Kilopounds per square inch (ksi). The unit system is selected in the Project Settings dialog. Export Data / Images Export data for further analysis or report writing: Copy the data and / or plots to the clipboard for easy import into Microsoft Word or your favorite word processor or image editing program. Copy the data and / or plots directly into Microsoft Excel. Save the plots to a JPEG or BMP image file. Print and Print Preview capabilities.

Display Options Numerous Display Options to customize the appearance of your plots: Change colors, fonts, line thickness. Grid overlay. Add plot title and show input data directly on plots. Zooming. Plot Mogis line (transition from brittle to ductile failure).

Grayscale for output to black and white printers

Quick Tour of RocLabThe following quick tour of RocLab will familiarize the user with the features of the program.

Entering Input DataThe primary means of user interaction with RocLab, is with the sidebar data input area, shown below. The sidebar is used for data input, and also for display of calculated output parameters. There are various methods of entering the input data for RocLab: ffd8ffe0 00104a4 Interactive Data Input 6494600 0102010 If you click on the 0480048 0000ffe2 0c58494 3435f50 This allows you to interactively observe the effect of parameter 524f464 changes, on the shape of the failure envelopes, and the output 94c4500 values. 0101000 00c484c ffd8ffe000104a4649460 696e6f0 0010201007500750000ff 2100000 Pick Dialogs e20c584943435f50524f46 6d6e747 494c4500010100000c484 2524742 c696e6f021000006d6e74 You may also enter input parameters using the Pick dialogs. When 2058595 725247422058595a2007c you select a Pick button, a2007ce e0002000900060031000 0002000 0616373704d534654000 9000600 00000494543207352474 3100006 20000000000000000000 1637370 000000000f6d600010000 4d53465 0000d32d485020200000 4000000 00000000000000000000 0049454 00000000000000000000 3207352 00000000000000000000 4742000 00000000000000000000 ffd8ffe00 0000000 00000000001163707274 0104a464 0000000 00000150000000336465 94600010 0000000 7363000001840000006c7 20100480 0000f6d 7747074000001f0000000 0480000ff 6000100 14626b70740000020400 e20c5849 000000d 0000147258595a000002 43435f505 32d4850 18000000146758595a00 24f46494c 2020000 00022c000000146258595 45000101 0000000 a0000024000000014646 00000c48 0000000 d6e64000002540000007 4c696e6f0 0000000 0646d6464000002c40000 21000006 0000000 0088767565640000034c0 d6e74725 0000000 00000867669657700000

Keyboard Entry If you type the numbers in the sidebar edit boxes with the keyboard, then the calculations are NOT automatically carried out. In this case, you must select the Compute option (available in the sidebar, the toolbar, or the Analysis menu), in order to re-compute the rock mass parameters and failure envelopes. ffd8ffe000104a4649460001 0201009500950000ffe20c58 4943435f50524f46494c4500 Triaxial Lab Test Data 010100000c484c696e6f0210 00006d6e747252474220585 You may also determine values of sigci 95a2007ce00020009000600 and mi, from triaxial lab test data for 310000616373704d5346540 intact rock. This is done with the Use 00000004945432073524742 Lab Data option, as described in a 00000000000000000000000 later section. When you select Apply or 00000f6d6000100000000d3 OK in the Calculate sigci, mi from Lab 2d485020200000000000000 Data dialog, the RocLab calculation is 00000000000000000000000 carried out, and all output values and 00000000000000000000000 failure envelopes are updated. 00000000000000000000000 00000000000011637072740 00001500000003364657363 000001840000006c7774707 4000001f000000014626b70 74000002040000001472585 95a00000218000000146758 595a0000022c00000014625 8595a000002400000001464 6d6e6400000254000000706 46d6464000002c400000088 767565640000034c0000008 676696577000003d4000000 246c756d69000003f8000000 146d6561730000040c00000 02474656368000004300000 000c725452430000043c000 0080c675452430000043c00 00080c625452430000043c0 000080c7465787400000000 436f7079726967687420286 3292031393938204865776c 6574742d5061636b6172642 0436f6d70616e79000064657 36300000000000000127352 47422049454336313936362 d322e310000000000000000 00000012735247422049454 336313936362d322e310000 00000000000000000000000 00000000000000000000000 0000

ffd8ffe0001 04a4649460 0010201007 b00790000ff e20c584943 435f50524f4 6494c45000 10100000c4 84c696e6f02 1000006d6e 7472524742 Estimating Input Parameters 2058595a20 07ce000200 Each of the parameters used as input for the Hoek-Brown criterion 0900060031 sigci, mi, GSI, and D, and input into the Generalized Hoek-Diederichs 0000616373 equation for determination of rock mass modulus Ei can be 704d534654 estimated using convenient charts and tables built into RocLab. 0000000049 4543207352 These charts and tables are accessed by selecting the Pick button 4742000000 ffd8ffe000104a464946000102 located beside each of the input 0000000000 01007f007f0000ffe20c5849434 parameter edit boxes in the sidebar. 0000000000 35f50524f46494c45000101000 00f6d60001 00c484c696e6f021000006d6e7 00000000d3 4725247422058595a2007ce00 2d48502020 0200090006003100006163737 When you select a Pick button, a table or 0000000000 04d5346540000000049454320 chart will appear, allowing you to determine a 0000000000 7352474200000000000000000 suitable value for the desired parameter. For 0000000000 00000000000f6d60001000000 example, the dialogs for estimation of mi and 0000000000 00d32d4850202000000000000 GSI (Rock Type = General) are shown 0000000000 0000000000000000000000000 below. 0000000000 0000000000000000000000000 0000000000 0000000000000000000000000 0000000000 0000000011637072740000015 0000000000 0000000336465736300000184 Once you have determined a value, select OK 0000116370 0000006c77747074000001f00 ffd8ffe000104a46494600010101007e007e0000ffe20c584943435f505 7274000001 0000014626b70740000020400 24f46494c4500010100000c484c696e6f021000006d6e7472524742205 5000000033 0000147258595a00000218000 8595a2007ce00020009000600310000616373704d5346540000000049 6465736300 000146758595a0000022c0000 454320735247420000000000000000000000000000f6d600010000000 0001840000 00146258595a0000024000000 0d32d4850202000000000000000000000000000000000000000000000 006c777470 014646d6e6400000254000000 000000000000000000000000000000000000000000000000001163707 74000001f0 70646d6464000002c40000008 274000001500000003364657363000001840000006c77747074000001 0000001462 8767565640000034c00000086 f000000014626b707400000204000000147258595a000002180000001 6b70740000 76696577000003d4000000246 46758595a0000022c000000146258595a0000024000000014646d6e64 0204000000 c756d69000003f8000000146d 0000025400000070646d6464000002c400000088767565640000034c0 147258595a 6561730000040c00000024746 000008676696577000003d4000000246c756d69000003f8000000146d 0000021800 56368000004300000000c7254 6561730000040c0000002474656368000004300000000c72545243000 0000146758 52430000043c0000080c67545 0043c0000080c675452430000043c0000080c625452430000043c0000 595a000002 2430000043c0000080c625452 080c7465787400000000436f707972696768742028632920313939382 2c00000014 430000043c0000080c7465787 04865776c6574742d5061636b61726420436f6d70616e790000646573 6258595a00 400000000436f707972696768 630000000000000012735247422049454336313936362d322e3100000 0002400000 7420286329203139393820486 0000000000000000012735247422049454336313936362d322e310000 0014646d6e 5776c6574742d5061636b6172 00000000000000000000000000000000000000000000000000 6400000254 6420436f6d70616e790000646 0000007064 5736300000000000000127352 in the Pick dialog. The value will be 6d64640000 47422049454336313936362d3 automatically loaded into the sidebar input 02c4000000 22e3100000000000000000000 data area, and the RocLab calculation will 8876756564 0012735247422049454336313 automatically be carried out (ie. output 0000034c00 936362d322e31000000000000 parameters and failure envelopes will be 0000867669 0000000000000000000000000 re-calculated using the selected input data). 6577000003 00000000000000000 d400000024 6c756d6900 0003f80000 00146d6561 730000040c

ffd8ffe000104a46494600010201007f007f0000ffe20c584943435f5052 4f46494c4500010100000c484c696e6f021000006d6e74725247422058 595a2007ce00020009000600310000616373704d53465400000000494 54320735247420000000000000000000000000000f6d6000100000000 GSI chart (Rock Type = General) d32d4850202000000000000000000000000000000000000000000000 ffd8ffe0001 00000000000000000000000000000000000000000000000000116370 Select the Pick button for each of sigci, mi, GSI, D and Ei, and 04a4649460 7274000001500000003364657363000001840000006c7774707400000 experiment with the dialogs. 0010201006 1f000000014626b707400000204000000147258595a00000218000000 000610000ff 146758595a0000022c000000146258595a0000024000000014646d6e6 Notice that there are TWO distinct GSI charts: e20c584943 40000025400000070646d6464000002c400000088767565640000034c 435f50524f4 0000008676696577000003d4000000246c756d69000003f8000000146 One for general rock mass types 6494c45000 d6561730000040c0000002474656368000004300000000c7254524300 which One for weak, heterogeneous rock mass types such as flysch, 10100000c4 00043c0000080c675452430000043c0000080c625452430000043c000 extends the useful range of GSI down to values as low as 5. 84c696e6f020080c7465787400000000436f70797269676874202863292031393938 1000006d6e 204865776c6574742d5061636b61726420436f6d70616e79000064657 7472524742 3630000000000000012735247422049454336313936362d322e31000 For further information about the Hoek-Brown classification parameters 2058595a20 000000000000000000012735247422049454336313936362d322e310 on the sigci, mi, GSI, D please consult Ref. 1. For further information 07ce000200 00000000000000000000000000000000000000000000000000000 see Ref. 2. Generalized Hoek-Diederichs rock mass modulus equation 0900060031 0000616373 704d534654 0000000049 4543207352 4742000000 0000000000 0000000000 00f6d600010 0000000d32 d485020200 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0001163707 2740000015 0000000336 4657363000 0018400000 06c7774707 4000001f000 000014626b 7074000002 0400000014 7258595a00 0002180000 0014675859 5a0000022c 0000001462 58595a0000 0240000000

Failure Envelope PlotsRocLab will plot the rock mass failure envelopes in: Principal stress space (sigma1 vs. sigma3) ffd8ffe000104a4649460001020100b700b70000ffe20c58494343 5f50524f46494c4500010100000c484c696e6f021000006d6e7472 5247422058595a2007ce00020009000600310000616373704d53 4654000000004945432073524742000000000000000000000000 0000f6d6000100000000d32d48502020000000000000000000000 0000000000000000000000000000000000000000000000000000 0000000000000000000001163707274000001500000003364657 363000001840000006c77747074000001f000000014626b707400 000204000000147258595a00000218000000146758595a000002 2c000000146258595a0000024000000014646d6e640000025400 000070646d6464000002c400000088767565640000034c000000 8676696577000003d4000000246c756d69000003f8000000146d6 561730000040c0000002474656368000004300000000c7254524 30000043c0000080c675452430000043c0000080c625452430000 043c0000080c7465787400000000436f707972696768742028632 92031393938204865776c6574742d5061636b61726420436f6d70 616e790000646573630000000000000012735247422049454336 313936362d322e31000000000000000000000012735247422049 454336313936362d322e31000000000000000000000000000000 000000000000000000000000 Shear Normal stress space (sigma normal vs. Tau) The plots correspond to the current data in the sidebar.

By default, BOTH principal stress AND shear-normal plots are displayed. However, you can choose to display either plot type on its own, by selecting the desired plot type from the toolbar, the Analysis menu or the right-click menu. Various display and analysis options are available, such as: Display equivalent Mohr-Coulomb envelope Stress sampler / Instantaneous Mohr-Coulomb sampler Customize plot appearance with Display Options (eg. grid overlay, line thickness, fonts etc), and zooming

ffd8ffe0001 ffd8ffe0001 04a4649460 04a4649460 001020100b 001020100b 800b80000ff 800b80000ff e20c584943 e20c584943 435f50524f4 435f50524f4 6494c45000 6494c45000 10100000c4 10100000c4 84c696e6f0 84c696e6f02 21000006d6 1000006d6e Right Click Menu e747252474 7472524742 TIP most of the plot display options, are also conveniently available in 22058595a2 2058595a20 the right-click menu, if you right-click the mouse anywhere in the plot 007ce00020 0090006003 07ce000200 display area. 1000061637 0900060031 3704d53465 0000616373 4000000004 Hoek-Brown Parameters 704d534654 9454320735 0000000049 2474200000 For a given set of input parameters (sigci, GSI, mi, and D), RocLab 4543207352 0000000000 4742000000 ffd8ffe000104a4649460001 calculates the parameters of the 0000000000 0000000000 0201008a008a0000ffe20c58 generalized Hoek-Brown failure criterion 000f6d6000 (mb, s and a). 0000000000 4943435f50524f46494c4500 100000000d 00f6d600010 010100000c484c696e6f0210 For a given value of intact modulus Ei, 32d4850202 0000000d32 00006d6e747252474220585 Roclab also calculates the rock mass 0000000000 d485020200 95a2007ce00020009000600 modulus Erm using the Generalized 0000000000 0000000000 310000616373704d5346540 Hoek-Diederichs equation in Ref. 2. 0000000000 0000000000 00000004945432073524742 0000000000 0000000000 0000000000 00000000000000000000000 These are displayed in the sidebar, as 0000000000 0000000000 00000f6d6000100000000d32 shown below. The Hoek-Brown failure 0000000000 d4850202000000000000000 envelopes which are plotted in RocLab, 0000000000 0000000000 00000000000000000000000 are generated using these values of mb, s 0000000000 0000000000 00000000000000000000000 and a. 0000000000 00000000000000000000000 0000011637 0000000000 00000000000116370727400 0727400000 0000000000 00015000000033646573630 1500000003 0001163707 00001840000006c77747074 3646573630 These parameters are calculated using the 2740000015 000001f000000014626b7074 latest version of the Hoek-Brown failure 0000184000 0000000336 00000204000000147258595 criterion. For a definition of these parameters, 0006c77747 4657363000 a0000021800000014675859 and the equations which define them, please 074000001f 0018400000 5a0000022c0000001462585 see Ref. 1. 0000000146 26b7074000 06c7774707 95a0000024000000014646d 0020400000 6e640000025400000070646 4000001f000 0147258595 000014626b d6464000002c40000008876 a000002180 7565640000034c000000867 7074000002 0000014675 6696577000003d400000024 0400000014 6c756d69000003f800000014 8595a00000 7258595a00 6d6561730000040c0000002 22c0000001 0002180000 47465636800000430000000 46258595a0 0014675859 0c725452430000043c000008 0000240000 5a0000022c 0c675452430000043c000008 00014646d6 0000001462 0c625452430000043c000008 e640000025 58595a0000 0c7465787400000000436f70 4000000706 0240000000 79726967687420286329203 46d6464000 14646d6e64 1393938204865776c657474 002c400000 0887675656 0000025400 2d5061636b61726420436f6d 40000034c0 70616e79000064657363000 000070646d 0000086766 00000000000127352474220 6464000002 9657700000 49454336313936362d322e3 c400000088 3d40000002 10000000000000000000000 7675656400 12735247422049454336313 46c756d690 00034c0000 936362d322e310000000000 00003f8000 0086766965 00000000000000000000000 000146d656 77000003d4 000000000000000000000 1730000040

ffd8ffe0001 04a4649460 0010201006f 00700000ffe 20c58494343 5f50524f464 94c45000101 00000c484c6 96e6f021000 006d6e7472 5247422058 Equivalent Mohr-Coulomb Parameters 595a2007ce0 In 0020009000 addition to the Hoek-Brown failure criterion 6003100006 parameters (mb, s and a), RocLab always calculates 16373704d5 equivalent Mohr-Coulomb parameters (cohesion and 3465400000 friction angle) for the rock mass. 0004945432 0735247420 Since most rock engineering software is still written 0000000000 ffd8ffe000104a46494600010201 in terms of the Mohr-Coulomb failure 0000000000 006f006f0000ffe20c584943435f5 criterion, the calculation of equivalent 0000000f6d6 0524f46494c4500010100000c48 Mohr-Coulomb parameters from the 0001000000 4c696e6f021000006d6e7472524 Hoek-Brown failure criterion, is an 00d32d4850 7422058595a2007ce0002000900 important feature of the RocLab 2020000000 0600310000616373704d5346540 program. 0000000000 000000049454320735247420000 0000000000 000000000000000000000000f6d 0000000000 6000100000000d32d4850202000 0000000000 000000000000000000000000000 The corresponding Mohr-Coulomb 0000000000 000000000000000000000000000 envelope can be viewed by selecting 0000000000 000000000000000000000000000 the Mohr-Coulomb Envelope option 0000000000 000000000001163707274000001 from the toolbar or the Analysis 0000000000 500000003364657363000001840 menu. 0000000011 000006c77747074000001f00000 6370727400 0014626b7074000002040000001 Failure Envelope Range 0001500000 47258595a000002180000001467 0033646573 58595a0000022c0000001462585 It is important to note that the 6300000184 95a0000024000000014646d6e64 Failure Envelope Range option has 0000006c777 0000025400000070646d6464000 a direct effect on the calculated Mohr4707400000 002c40000008876756564000003 Coulomb parameters. 1f000000014 4c0000008676696577000003d40 626b707400 00000246c756d69000003f80000 For details about the Mohr-Coulomb 0002040000 00146d6561730000040c0000002 fitting procedure, and the significance 0014725859 474656368000004300000000c72 of the Failure Envelope Range option, 5a00000218 5452430000043c0000080c67545 see Ref. 1 (section 4: Mohr-Coulomb 0000001467 2430000043c0000080c62545243 Criterion, and section 6: 58595a0000 0000043c0000080c74657874000 Determination of 022c0000001 00000436f707972696768742028 46258595a0 63292031393938204865776c657 0000240000 4742d5061636b61726420436f6d 00014646d6 70616e790000646573630000000 e640000025 000000012735247422049454336 4000000706 313936362d322e3100000000000 46d6464000 000000000001273524742204945 002c4000000 4336313936362d322e310000000 8876756564 000000000000000000000000000 0000034c000 00000000000000000000 0008676696 577000003d 4000000246c 756d690000 03f80000001 46d6561730 000040c0000 0024746563

ffd8ffe0001 04a4649460 0010201006 f00700000ff e20c584943 435f50524f4 6494c45000 10100000c4 84c696e6f0 21000006d6 e747252474 Other Rock Mass Parameters 22058595a2 007ce00020 At the bottom of the sidebar, you will notice that the following rock 0090006003 mass parameters are also calculated: 1000061637 3704d53465 Sigt (rock mass tensile strength) 4000000004 Sigc (uniaxial rock mass compressive strength) 9454320735 ffd8ffe000104a4649460001020 Sigcm (global rock mass compressive strength) 2474200000 1007000700000ffe20c584943435 0000000000 f50524f46494c4500010100000c4 Erm (rock mass deformation modulus) 0000000000 84c696e6f021000006d6e747252 000f6d6000 47422058595a2007ce000200090 100000000d 00600310000616373704d53465 32d4850202 40000000049454320735247420 0000000000 00000000000000000000000000 0000000000 0f6d6000100000000d32d485020 For the definitions of these parameters, and 0000000000 20000000000000000000000000 the equations used to calculate them, 0000000000 00000000000000000000000000 please see Ref. 1 (sigt,sigc,sigcm) and the 0000000000 00000000000000000000000000 Generalized Hoek-Diederichs equation in 0000000000 00000000000000000011637072 Ref 2. (Erm). 0000000000 74000001500000003364657363 0000000000 000001840000006c77747074000 In particular, you will notice that there are 0000000000 001f000000014626b7074000002 two values of rock mass compressive 0000011637 04000000147258595a000002180strength which are calculated by RocLab 0727400000 00000146758595a0000022c0000 sigc and sigcm. For a discussion of 1500000003 00146258595a000002400000001how these two parameters are 3646573630 4646d6e6400000254000000706 defined, and how they may be used, 0000184000 46d6464000002c4000000887675 please see Ref. 1 section 5: Rock 0006c77747 65640000034c000000867669657 Mass Strength. 074000001f 7000003d4000000246c756d6900 0000000146 0003f8000000146d65617300000 26b7074000 40c000000247465636800000430 0020400000 0000000c725452430000043c000 0147258595 0080c675452430000043c000008 a000002180 0c625452430000043c0000080c7 0000014675 465787400000000436f70797269 8595a00000 67687420286329203139393820 22c0000001 4865776c6574742d5061636b617 46258595a0 26420436f6d70616e7900006465 0000240000 73630000000000000012735247 00014646d6 422049454336313936362d322e e640000025 31000000000000000000000012 4000000706 73524742204945433631393636 46d6464000 2d322e31000000000000000000 002c400000 00000000000000000000000000 0887675656 0000000000 40000034c0 0000086766 9657700000 3d40000002 46c756d690 00003f8000 000146d656 1730000040

Triaxial Lab Test DataAnother feature of RocLab, is the ability to input triaxial lab test data (sigma1 / sigma3 data pairs), in order to determine the intact rock parameters sigci and mi. This is done as follows: 1. Select the Use Lab Data option from the Analysis menu or the toolbar. 2. The data can be entered in a spreadsheet, or imported from a file, as shown in the dialog below. 3. A curve fit is then performed on the data, using the MarquardtLevenberg fitting technique, and values of sigci and mi are obtained. 4. After entering the data, select OK in the dialog, and the calculated values of ffd8ffe000104a4649460001020100ba00ba0000ffe20c58 sigci and 4943435f50524f46494c4500010100000c484c696e6f0210 mi will be 00006d6e74725247422058595a2007ce00020009000600 used to 310000616373704d534654000000004945432073524742 calculate 0000000000000000000000000000f6d6000100000000d3 the Hoek2d48502020000000000000000000000000000000000000 Brown 0000000000000000000000000000000000000000000000 strength 0000000000001163707274000001500000003364657363 000001840000006c77747074000001f000000014626b707 400000204000000147258595a000002180000001467585 95a0000022c000000146258595a0000024000000014646 d6e640000025400000070646d6464000002c4000000887 67565640000034c0000008676696577000003d40000002 46c756d69000003f8000000146d6561730000040c000000 2474656368000004300000000c725452430000043c0000 080c675452430000043c0000080c625452430000043c000 0080c7465787400000000436f7079726967687420286329 2031393938204865776c6574742d5061636b6172642043 6f6d70616e790000646573630000000000000012735247 422049454336313936362d322e31000000000000000000 000012735247422049454336313936362d322e31000000 0000000000000000000000000000000000000000000000 00 parameters and failure envelopes.

Obtaining actual values of sigci and mi from triaxial lab test data, is of course always recommended, if such data is available. It should be emphasized that a large number of test results is not always necessary, and good results can be obtained from a relatively small number of data points (eg. 6 or 7 triaxial tests). If triaxial lab data is not available, values of sigci and mi can always be estimated in RocLab, using the Pick dialogs described previously.

ffd8ffe0001 04a4649460 0010201006 100600000ff e20c584943 435f50524f4 6494c45000 10100000c4 84c696e6f0 21000006d6 e747252474 Example 1 Tunnel, undisturbed (D = 0) 22058595a2 007ce00020 Consider an undisturbed in situ rock mass surrounding a tunnel at a 0090006003 ffd8ffe000104a4649460001 depth of 100 meters, with the following 1000061637 0201008c008c0000ffe20c58 Hoek-Brown classification parameters. 3704d53465 4943435f50524f46494c4500 4000000004 010100000c484c696e6f0210 9454320735 00006d6e747252474220585 2474200000 95a2007ce00020009000600 Enter this data in the sidebar input data area. 0000000000 310000616373704d5346540 Also, enter the following data to determine the 0000000000 00000004945432073524742 Failure Envelope Range (sig3max). This is used 000f6d6000 00000000000000000000000 for the equivalent Mohr-Coulomb calculation: ffd8ffe000104a46494600010 100000000d 00000f6d6000100000000d3 201007c007c0000ffe20c58494 32d4850202 2d485020200000000000000 0000000000 3435f50524f46494c45000101 00000000000000000000000 0000000000 00000c484c696e6f021000006 Now press Compute. 00000000000000000000000 0000000000 d6e74725247422058595a200 00000000000000000000000 ffd8ffe000104a464946000102010 0000000000 7ce0002000900060031000061 The resulting output will be displayed in 00000000000011637072740 07900790000ffe20c584943435f505 0000000000 6373704d5346540000000049 the sidebar, and the failure envelopes 00001500000003364657363 24f46494c4500010100000c484c69 0000000000 454320735247420000000000 will be calculated. 000001840000006c7774707 6e6f021000006d6e7472524742205 0000000000 000000000000000000f6d6000 4000001f000000014626b70 8595a2007ce000200090006003100 0000000000 100000000d32d48502020000 Notice the equivalent Mohr-Coulomb 74000002040000001472585 00616373704d5346540000000049 0000000000 000000000000000000000000 parameters which have been calculated: 95a00000218000000146758 4543207352474200000000000000 0000011637 000000000000000000000000 595a0000022c00000014625 00000000000000f6d600010000000 0727400000 000000000000000000000000 8595a000002400000001464 0d32d48502020000000000000000 1500000003 000000000000000000011637 6d6e6400000254000000706 0000000000000000000000000000 3646573630 072740000015000000033646 The envelope corresponding to these 0000000000000000000000000000 46d6464000002c400000088 0000184000 57363000001840000006c777 parameters, can be viewed on the plots, by 0000000000000000000000011637 767565640000034c0000008 0006c77747 47074000001f000000014626b selecting the Mohr-Coulomb strength 0727400000150000000336465736 676696577000003d4000000 074000001f 707400000204000000147258 envelope option, from the toolbar or the 3000001840000006c777470740000 246c756d69000003f8000000 595a00000218000000146758 0000000146 01f000000014626b7074000002040 Analysis menu. 146d6561730000040c00000 26b7074000 595a0000022c0000001462585 00000147258595a0000021800000 02474656368000004300000 0020400000 95a0000024000000014646d6 0146758595a0000022c0000001462 000c725452430000043c000 0147258595 e640000025400000070646d6 58595a0000024000000014646d6e 0080c675452430000043c00 a000002180 464000002c40000008876756 640000025400000070646d646400 00080c625452430000043c0 5640000034c0000008676696 0000014675 0002c400000088767565640000034 000080c7465787400000000 577000003d4000000246c756 8595a00000 c0000008676696577000003d40000 436f7079726967687420286 22c0000001 d69000003f8000000146d6561 00246c756d69000003f8000000146 3292031393938204865776c 46258595a0 730000040c00000024746563 d6561730000040c00000024746563 6574742d5061636b6172642 0000240000 68000004300000000c725452 68000004300000000c72545243000 0436f6d70616e7900006465 430000043c0000080c6754524 00014646d6 0043c0000080c675452430000043c 73630000000000000012735 30000043c0000080c62545243 e640000025 0000080c625452430000043c00000 24742204945433631393636 0000043c0000080c746578740 4000000706 80c7465787400000000436f707972 2d322e31000000000000000 6967687420286329203139393820 46d6464000 0000000436f70797269676874 00000001273524742204945 4865776c6574742d5061636b61726 002c400000 202863292031393938204865 4336313936362d322e31000 776c6574742d5061636b6172 0887675656 420436f6d70616e79000064657363 00000000000000000000000 6420436f6d70616e790000646 40000034c0 0000000000000012735247422049 00000000000000000000000 573630000000000000012735 0000086766 454336313936362d322e31000000 00000 247422049454336313936362 9657700000 0000000000000000127352474220 d322e3100000000000000000 3d40000002 49454336313936362d322e310000 000001273524742204945433 46c756d690 0000000000000000000000000000 6313936362d322e310000000 00003f8000 0000000000000000000000 000146d656 000000000000000000000000 1730000040 00000000000000000000000

ffd8ffe00010 ffd8ffe0001 4a464946000 04a4649460 10201008d00 0010201008 8d0000ffe20c d008d0000ff 584943435f50 e20c5849434 524f46494c45 35f50524f46 00010100000 494c4500010 c484c696e6f0 100000c484c 21000006d6e 696e6f02100 To get a better look at the MC envelope, lets view only the Normal vs. Shear 74725247422 0006d6e747 stress plot. Select the Normal vs. Shear Stress option from the Analysis menu or 058595a2007 2524742205 the toolbar. This will hide the principal stress plot, and show only the Normal vs ce000200090 00600310000 8595a2007ce ffd8ffe000104a46494600010201009c009c0000ffe20c584943435f50 Shear 616373704d5 524f46494c4500010100000c484c696e6f021000006d6e74725247422 stress plot, 0002000900 34654000000 058595a2007ce00020009000600310000616373704d5346540000000maximized 0600310000 00494543207 049454320735247420000000000000000000000000000f6d60001000 in the view. 616373704d 35247420000 00000d32d4850202000000000000000000000000000000000000000 5346540000 00000000000 0000000000000000000000000000000000000000000000000000000 0000494543 01163707274000001500000003364657363000001840000006c77747 00000000000 2073524742 074000001f000000014626b707400000204000000147258595a00000 If you 00f6d6000100 0000000000 218000000146758595a0000022c000000146258595a0000024000000examine the 000000d32d4 0000000000 014646d6e640000025400000070646d6464000002c40000008876756MC 85020200000 00000000f6d 5640000034c0000008676696577000003d4000000246c756d6900000 envelope, 00000000000 6000100000 3f8000000146d6561730000040c00000024746563680000043000000 you can 00000000000 00000000000 000d32d485 00c725452430000043c0000080c675452430000043c0000080c62545 graphically 00000000000 2430000043c0000080c7465787400000000436f70797269676874202 confirm the 0202000000 00000000000 863292031393938204865776c6574742d5061636b61726420436f6d7 calculated 0000000000 00000000000 0616e79000064657363000000000000001273524742204945433631 values of 0000000000 00000000000 3936362d322e3100000000000000000000001273524742204945433 cohesion, 0000000000 00000000000 6313936362d322e3100000000000000000000000000000000000000 friction 0000000000 0000000000000000 angle, and 00116370727 0000000000 also the 40000015000 0000000000 rock mass tensile strength sigt. The tensile strength is the negative value 00003364657 0000000000 of normal stress, at the origin of the failure envelope. 36300000184 0000000000 0000006c777 0000000001 47074000001f 00000001462 1637072740 6b707400000 0000150000 20400000014 0003364657 7258595a000 3630000018 00218000000 40000006c77 146758595a0 7470740000 000022c0000 01f00000001 00146258595 4626b70740 a0000024000 0000204000 000014646d6 0001472585 e6400000254 95a0000021 00000070646 d6464000002 8000000146 c4000000887 758595a000 67565640000 0022c000000 034c0000008 146258595a 67669657700 0000024000 0003d400000 000014646d 0246c756d69 6e64000002 000003f80000 5400000070 00146d65617 646d646400 30000040c00 0002c400000 00002474656 0887675656 36800000430 0000000c725 40000034c00 45243000004 0000867669 3c0000080c6 6577000003 75452430000 d400000024

ffd8ffe0001 04a4649460 0010201006 000600000ff e20c584943 435f50524f4 6494c45000 10100000c4 84c696e6f02 1000006d6e 7472524742 Example 2 Slope, disturbed (D = 1) 2058595a20 07ce000200 Consider a rock mass with the same basic parameters as the previous 0900060031 example, but in a highly disturbed slope of 100 meters height, with a 0000616373 disturbance factor D = 1. 704d534654 ffd8ffe000104a464946000 0000000049 10201009600960000ffe20c Enter disturbance factor D = 1. 4543207352 584943435f50524f46494c4 4742000000 500010100000c484c696e6f 0000000000 021000006d6e7472524742 Enter the following data to determine the 0000000000 2058595a2007ce00020009 ffd8ffe000104a46494600010 Failure Envelope Range (sig3max): 00f6d60001 000600310000616373704d 00000000d3 201008000800000ffe20c5849 5346540000000049454320 2d48502020 43435f50524f46494c4500010 7352474200000000000000 0000000000 100000c484c696e6f02100000 00000000000000f6d60001 0000000000 6d6e74725247422058595a20 Now press Compute. 00000000d32d4850202000 0000000000 07ce00020009000600310000 0000000000000000000000 ffd8ffe000104a46494600010201 0000000000 616373704d53465400000000 The resulting output will be displayed in 0000000000000000000000 008000800000ffe20c584943435f5 0000000000 494543207352474200000000 the sidebar, and the failure envelopes will 0000000000000000000000 0524f46494c4500010100000c484 0000000000 00000000000000000000f6d6 be calculated. 0000000000000000000000 c696e6f021000006d6e747252474 0000000000 000100000000d32d48502020 0000116370727400000150 22058595a2007ce000200090006 0000000000 000000000000000000000000 Notice the equivalent Mohr-Coulomb 00310000616373704d534654000 0000003364657363000001 0000000000 000000000000000000000000 parameters which have been calculated: 000004945432073524742000000 840000006c777470740000 0000116370 000000000000000000000000 0000000000000000000000f6d600 01f000000014626b707400 7274000001 000000000000000000000011 0100000000d32d4850202000000 000204000000147258595a 5000000033 637072740000015000000033 000000000000000000000000000 0000021800000014675859 6465736300 64657363000001840000006c 000000000000000000000000000 5a0000022c000000146258 0001840000 77747074000001f000000014 000000000000000000000000000 595a000002400000001464 006c777470 626b70740000020400000014 000000001163707274000001500 6d6e640000025400000070 74000001f0 7258595a0000021800000014 000003364657363000001840000 646d6464000002c4000000 6758595a0000022c00000014 0000001462 006c77747074000001f000000014 88767565640000034c0000 6b70740000 6258595a0000024000000014 626b70740000020400000014725 008676696577000003d400 0204000000 646d6e640000025400000070 8595a0000021800000014675859 0000246c756d69000003f80 147258595a 646d6464000002c400000088 5a0000022c000000146258595a0 00000146d6561730000040 0000021800 767565640000034c00000086 000024000000014646d6e640000 c000000247465636800000 76696577000003d400000024 0000146758 025400000070646d6464000002c 4300000000c72545243000 6c756d69000003f800000014 595a000002 400000088767565640000034c00 0043c0000080c675452430 2c00000014 6d6561730000040c00000024 00008676696577000003d400000 000043c0000080c6254524 6258595a00 74656368000004300000000c 0246c756d69000003f8000000146 30000043c0000080c74657 0002400000 725452430000043c0000080c d6561730000040c000000247465 87400000000436f7079726 675452430000043c0000080c 0014646d6e 6368000004300000000c7254524 9676874202863292031393 625452430000043c0000080c 6400000254 30000043c0000080c6754524300 938204865776c6574742d5 7465787400000000436f7079 0000007064 00043c0000080c6254524300000 061636b61726420436f6d7 43c0000080c7465787400000000 6d64640000 726967687420286329203139 0616e79000064657363000 436f707972696768742028632920 02c4000000 3938204865776c6574742d50 0000000000012735247422 61636b61726420436f6d7061 8876756564 31393938204865776c6574742d5 049454336313936362d322 6e7900006465736300000000 0000034c00 061636b61726420436f6d70616e7 e310000000000000000000 000000127352474220494543 0000867669 900006465736300000000000000 0001273524742204945433 36313936362d322e31000000 6577000003 127352474220494543363139363 6313936362d322e3100000 62d322e31000000000000000000 d400000024 000000000000000012735247 0000000000000000000000 422049454336313936362d32 6c756d6900 000012735247422049454336313 0000000000000000000000 2e3100000000000000000000 0003f80000 936362d322e3100000000000000 00000 000000000000000000000000 00146d6561 000000000000000000000000000 0000000000 730000040c 0000000000000

ffd8ffe00010 4a464946000 10201009600 960000ffe20c 584943435f50 524f46494c45 00010100000 ffd8ffe000104a4649460001020100b600b60000ffe20c584943435f5 c484c696e6f0 0524f46494c4500010100000c484c696e6f021000006d6e747252474 21000006d6e 22058595a2007ce00020009000600310000616373704d534654000 74725247422 0000049454320735247420000000000000000000000000000f6d600 058595a2007 0100000000d32d4850202000000000000000000000000000000000 ce000200090 000000000000000000000000000000000000000000000000000000 00600310000 000000001163707274000001500000003364657363000001840000 616373704d5 006c77747074000001f000000014626b70740000020400000014725 34654000000 8595a00000218000000146758595a0000022c000000146258595a0 00494543207 35247420000 000024000000014646d6e640000025400000070646d6464000002c 00000000000 400000088767565640000034c0000008676696577000003d400000 00000000000 0246c756d69000003f8000000146d6561730000040c000000247465 00f6d6000100 6368000004300000000c725452430000043c0000080c67545243000 000000d32d4 0043c0000080c625452430000043c0000080c746578740000000043 85020200000 6f70797269676874202863292031393938204865776c6574742d506 00000000000 1636b61726420436f6d70616e790000646573630000000000000012 00000000000 735247422049454336313936362d322e3100000000000000000000 00000000000 0012735247422049454336313936362d322e310000000000000000 00000000000 00000000000000000000000000000000000000 00000000000 Compare the equivalent Mohr-Coulomb parameters and envelopes, calculated in 00000000000 Example 1 and Example 2. This demonstrates the significant effect which the 00000000000 disturbance factor D, can have on the calculated rock mass strength. 00000000000 00116370727 For information about the Disturbance Factor, see Ref. 1 section 7: 40000015000 Estimation of Disturbance Factor D. 00003364657 36300000184 0000006c777 47074000001f 00000001462 6b707400000 20400000014 7258595a000 00218000000 146758595a0 000022c0000 00146258595 a0000024000 000014646d6 e6400000254 00000070646 d6464000002 c4000000887 67565640000 034c0000008 67669657700 0003d400000 0246c756d69 000003f80000 00146d65617 30000040c00 00002474656 36800000430 0000000c725 45243000004 3c0000080c67 54524300000

Stress SamplerThe Stress Sampler option allows the user to graphically obtain the exact stress coordinates at any point along the failure envelopes. This is done as follows: 1. Select the Stress Sampler option from the toolbar, the right-click menu or the Analysis menu. 2. Single click the left mouse button, at any value of sigma3 (on the principal stress plot), or any value of normal stress (on the shearnormal stress plot). 3. The stress coordinates will be displayed, corresponding to the value of sigma3 or normal stress, at which the mouse was clicked. A vertical dotted line will be displayed on the plots, to mark the location. 4. Alternatively, if you click and HOLD the left mouse button on either of the plots, and DRAG the mouse left or right, the stress coordinates of the failure envelopes will be continuously displayed, as you move the mouse. 5. NOTE: if the equivalent Mohr-Coulomb envelopes are also displayed, then ffd8ffe000104a46494600010201006000600000ffe20c58494 the 3435f50524f46494c4500010100000c484c696e6f021000006d stress 6e74725247422058595a2007ce000200090006003100006163 73704d5346540000000049454320735247420000000000000 000000000000000f6d6000100000000d32d485020200000000 0000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000011637072740 00001500000003364657363000001840000006c7774707400 0001f000000014626b707400000204000000147258595a0000 0218000000146758595a0000022c000000146258595a000002 4000000014646d6e640000025400000070646d6464000002c4 00000088767565640000034c0000008676696577000003d40 00000246c756d69000003f8000000146d6561730000040c000 0002474656368000004300000000c725452430000043c00000 80c675452430000043c0000080c625452430000043c0000080 c7465787400000000436f70797269676874202863292031393 938204865776c6574742d5061636b61726420436f6d70616e7 9000064657363000000000000001273524742204945433631 3936362d322e3100000000000000000000001273524742204 9454336313936362d322e3100000000000000000000000000 0000000000000000000000000000 coordinates of BOTH the Hoek-Brown, and equivalent Mohr-Coulomb envelopes will be displayed.

ffd8ffe00010 4a464946000 10201006000 600000ffe20c5 84943435f505 24f46494c450 0010100000c4 84c696e6f021 000006d6e74 72524742205 8595a2007ce0 Instantaneous Mohr-Coulomb Sampler 00200090006 00310000616 The Instantaneous Mohr-Coulomb Sampler option allows the user 373704d5346 to graphically obtain the instantaneous Mohr-Coulomb parameters 54000000004 (cohesion and friction angle), at any point along the Hoek-Brown failure 94543207352 envelopes. This is done as follows: 47420000000 00000000000 1. Select the Instantaneous MC Sampler option from the toolbar, the 0000000000f6 right-click menu or the Analysis menu. d6000100000 2. Single click the left mouse button, at any value of sigma3 (on the 000d32d4850 principal stress plot), or any value of normal stress (on the shear20200000000 normal stress plot). 00000000000 3. The instantaneous Mohr-Coulomb envelope (tangential line) will 00000000000 appear on the plots, for the value of sigma3 or normal stress, at 00000000000 which the mouse was clicked. The instantaneous values of cohesion 00000000000 and friction angle will be displayed, as well as the stress 00000000000 coordinates. A vertical dotted line will be displayed on the plots, to 00000000000 mark the location. 00000000000 4. Alternatively, if you click and HOLD the left mouse button on either 00000000001 of the plots, and DRAG the mouse left or right, the instantaneous 16370727400 Mohr-Coulomb envelope and coordinates, will be continuously 00015000000 03364657363 ffd8ffe000104a46494600010201006000600000ffe20c584943 00000184000 435f50524f46494c4500010100000c484c696e6f021000006d6e 0006c7774707 74725247422058595a2007ce000200090006003100006163737 4000001f0000 04d53465400000000494543207352474200000000000000000 00014626b70 00000000000f6d6000100000000d32d48502020000000000000 74000002040 00000000000000000000000000000000000000000000000000 00000147258 00000000000000000000000000000000116370727400000150 595a0000021 0000003364657363000001840000006c77747074000001f0000 80000001467 00014626b707400000204000000147258595a0000021800000 58595a00000 0146758595a0000022c000000146258595a0000024000000014 22c000000146 646d6e640000025400000070646d6464000002c400000088767 258595a0000 565640000034c0000008676696577000003d4000000246c756d 02400000001 69000003f8000000146d6561730000040c00000024746563680 4646d6e6400 00004300000000c725452430000043c0000080c675452430000 00025400000 043c0000080c625452430000043c0000080c746578740000000 070646d6464 0436f70797269676874202863292031393938204865776c6574 000002c40000 742d5061636b61726420436f6d70616e7900006465736300000 00887675656 00000000012735247422049454336313936362d322e3100000 40000034c000 0000000000000000012735247422049454336313936362d322 00086766965 e3100000000000000000000000000000000000000000000000 77000003d40 0000000 00000246c756 displayed, as you move the mouse. d69000003f80 00000146d65 61730000040c 00000024746 56368000004 300000000c72 54524300000 43c0000080c6 75452430000 043c0000080c

ffd8ffe00010 4a464946000 10201006000 600000ffe20c5 84943435f505 24f46494c450 0010100000c4 84c696e6f021 000006d6e74 72524742205 8595a2007ce0 00200090006 00310000616 373704d5346 54000000004 94543207352 47420000000 00000000000 0000000000f6 d6000100000 000d32d4850 20200000000 00000000000 00000000000 00000000000 00000000000 00000000000 00000000000 00000000000 00000000001 16370727400 00015000000 03364657363 00000184000 0006c7774707 4000001f0000 00014626b70 74000002040 00000147258 595a0000021 80000001467 58595a00000 22c000000146 258595a0000 02400000001 4646d6e6400 00025400000 070646d6464 000002c40000 00887675656 40000034c000 00086766965 77000003d40 00000246c756 d69000003f80 00000146d65 61730000040c 00000024746 56368000004 300000000c72 54524300000 43c0000080c6 75452430000 043c0000080c

Exporting Data / ImagesThe RocLab analysis results and failure envelope plots, can be exported to other programs for report writing, further analysis, etc. This can be done in various ways. The Copy Data option in the sidebar or the Edit menu, will copy the contents of the sidebar (ie. all input and output parameters) to the clipboard. From the clipboard, this can be pasted into a word processor or spreadsheet. This provides a handy analysis summary. The Copy option in the toolbar or the Edit menu, will copy an image of the current failure envelope which is displayed, to the clipboard. From the clipboard, this can be pasted into reports or image editing programs, etc. The failure envelope plots can also be saved directly to a JPEG or BMP image file, with the Export Image File option. This is available in the File menu, or the right click menu.

One Click Export to Excel The most powerful data export feature is the following with a single mouse click, all data AND plots can be exported to Microsoft Excel. To do this: 1. Select the Export to Excel toolbar button. 2. If you have Excel installed on your computer, the Excel program will be automatically started, and all analysis input and output data will be exported to an Excel spreadsheet. 3. Failure envelope plots will then be generated in Excel. 4. This all takes place with a single mouse click !!! Note that the plots which are generated in Excel, correspond to the failure envelope plot(s) which you are currently viewing. For example, if you are only viewing the shear-normal plot, then only the shear-normal data and plot, will be generated in Excel. If you are viewing both plots (principal stress and shear-normal), then both plots will be generated in Excel. Also, if the equivalent Mohr-Coulomb envelope is displayed, this will also be plotted in Excel. Finally, note that the number of data points used to create each failure envelope, is controlled in the Display Options dialog in RocLab.

ffd8ffe000104 ffd8ffe0001 a46494600010 04a4649460 201006000600 0010201006 000ffe20c5849 000600000ff 43435f50524f4 e20c5849434 6494c4500010 35f50524f46 100000c484c6 494c4500010 96e6f02100000 100000c484c 6d6e74725247 696e6f02100 422058595a20 Display Options 0006d6e747 07ce00020009 2524742205 000600310000 8595a2007ce The appearance of the Failure Envelope plots may be customized with 616373704d53 0002000900 Display Options, zooming, and other options. 465400000000 0600310000 494543207352 616373704d Display Options is available in the toolbar, the View menu, and also 474200000000 in the right-click 5346540000 ffd8ffe000104a46494600010201008400840000ffe 000000000000 menu (if you 0000494543 20c584943435f50524f46494c4500010100000c484c 00000000f6d60 right-click the 2073524742 696e6f021000006d6e74725247422058595a2007ce 00100000000d mouse 0000000000 00020009000600310000616373704d534654000000 32d485020200 anywhere in the 0000000000 004945432073524742000000000000000000000000 000000000000 Failure 00000000f6d 0000f6d6000100000000d32d485020200000000000 000000000000 Envelope 6000100000 000000000000000000000000000000000000000000 000000000000 display area). 000000000000000000000000000000000000000000 000d32d485 000000000000 116370727400000150000000336465736300000184 0202000000 000000000000 0000006c77747074000001f000000014626b707400 000000000000 000204000000147258595a00000218000000146758 0000000000 000000000000 595a0000022c000000146258595a00000240000000 0000000000 000000000116 14646d6e640000025400000070646d6464000002c4 Most of the Display 0000000000 370727400000 00000088767565640000034c000000867669657700 Options are self0000000000 150000000336 0003d4000000246c756d69000003f8000000146d65 explanatory, and it is 0000000000 465736300000 61730000040c000000247465636800000430000000 left to the user to 0000000000 1840000006c7 0c725452430000043c0000080c675452430000043c experiment with the 0000000000 774707400000 0000080c625452430000043c0000080c7465787400 options. However, we 0000000000 1f00000001462 000000436f70797269676874202863292031393938 will note the purpose 0000000001 6b7074000002 204865776c6574742d5061636b61726420436f6d70 of the following 1637072740 040000001472 616e79000064657363000000000000001273524742 options: 0000150000 58595a000002 2049454336313936362d322e310000000000000000 0003364657 00000012735247422049454336313936362d322e31 180000001467 3630000018 000000000000000000000000000000000000000000 Mogis Line 58595a000002 40000006c77 000000000000 Mogis Line defines 2c0000001462 the ratio of major 7470740000 58595a000002 01f00000001 and minor effective principal stresses at which there is a transition 400000001464 4626b70740 from brittle to ductile failure. This line is simply defined by sig1/sig3 = 6d6e64000002 0000204000 3.4, and is plotted as a green line on the principal stress plot, when the 540000007064 0001472585 Mogis Line option is selected in the Display Options dialog. 6d6464000002 95a0000021 c40000008876 If the principal stress failure envelope lies ABOVE Mogis line, this 8000000146 756564000003 indicates a brittle failure mode. 758595a000 4c0000008676 If the principal stress failure envelope lies BELOW Mogis line, this 0022c000000 696577000003 indicates a ductile failure mode. This may occur with low values of 146258595a d4000000246c GSI, for example. 756d69000003f 0000024000 8000000146d6 000014646d 561730000040 6e64000002 c00000024746 5400000070 563680000043 646d646400 00000000c725 0002c400000 452430000043 0887675656 c0000080c675 40000034c00 452430000043 0000867669 c0000080c625 6577000003 452430000043 d400000024

ffd8ffe0001 04a4649460 0010201005 f005f0000ffe 20c5849434 35f50524f46 494c450001 0100000c48 4c696e6f021 000006d6e7 4725247422 058595a200 7ce0002000 9000600310 0006163737 04d5346540 0000000494 5432073524 7420000000 0000000000 0000000000 0f6d600010 0000000d32 d485020200 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0001163707 2740000015 0000000336 4657363000 0018400000 06c7774707 4000001f00 0000014626 b707400000 2040000001 47258595a0 0000218000 0001467585 95a0000022 c000000146 258595a000 0024000000 014646d6e6 4000002540 0000070646 d646400000 2c40000008 8767565640 000034c000 0008676696 577000003d 4000000246 c756d69000 003f800000 0146d65617 30000040c0

Zoom Extents The Zoom Extents option will automatically scale the axes of the failure envelopes, so that all possible failure envelopes, for the current value of sigci, will be visible on the plot. This corresponds to maximum values of GSI (= 100) and mi ( = 40). 1. To demonstrate this, select the Zoom Extents option. 2. Use the interactive arrow buttons, to increase the value of GSI to 100, and the value of mi to 40. 3. Observe the failure envelope plots. When GSI = 100 and mi = 40, the extent of the principal stress envelope will correspond to the maximum extent automatically calculated by the Zoom Extents option. You may find the Zoom Extents option useful for interactive demonstration of parameter changes on the failure envelope.

ffd8ffe0001 04a4649460 0010201006 100600000ff e20c584943 435f50524f4 6494c45000 10100000c4 84c696e6f0 21000006d6 e747252474 22058595a2 007ce00020 1. Hoek, E., Carranza-Torres, C.T., and Corkum, B. (2002), 0090006003 Hoek-Brown failure criterion 2002 edition. Proc. North 1000061637 American Rock Mechanics Society meeting in Toronto in 3704d53465 July 2002. 4000000004 2. Hoek, E and Diederichs, M.S. (2006), Empirical estimation of 9454320735 rock mass modulus. International Journal of Rock 2474200000 Mechanics and Mining Sciences, 43, 203215 0000000000 3. Hoek, Evert, (2006), A Brief History of the Hoek-Brown 0000000000 Failure Criterion, unpublished document. 000f6d6000 100000000d 32d4850202 4. Hoek, Evert, Practical Rock Engineering An Ongoing Set of 0000000000 Notes, available on the Rocscience website, www.rocscience.com 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000011637 0727400000 1500000003 3646573630 0000184000 0006c77747 074000001f 0000000146 26b7074000 0020400000 0147258595 a000002180 0000014675 8595a00000 22c0000001 46258595a0 0000240000 00014646d6 e640000025 4000000706 46d6464000 002c400000 0887675656 40000034c0 0000086766 9657700000 3d40000002 46c756d690 00003f8000 000146d656 1730000040

References