Introduction: RS3 Tutorial 4 Cross Tunnel
Welcome to RS3. This tutorial demonstrates how to model a
typical cross tunnel between two twin tunnels using the model
shown above. The model uses typical tunnel dimensions and
is based on the Mont Cénis tunnel in Savoie, France.
The finished product of this tutorial can be found in the
Tutorial 04 Cross Tunnel.rs3dmodel file. All tutorial files
installed with RS3 can be accessed by selecting File 
Recent  Tutorials folder from the RS3 main menu.
CONTENTS
Introduction: RS3 Tutorial 4 Cross Tunnel ........ 1
Step 6: Adding Stress Loading ........................ 8
Step 1: Starting the Model ............................... 2
Applying Field Stress To The Model ............ 8
Creating A Blank Document ......................... 2
Step 7: Setting Boundary Conditions ............... 8
Step 2: Editing The Project Settings................. 2
Adding Model Restraints .............................. 8
Configuring The Units................................... 2
Step 8: Meshing .............................................. 9
Other Options ............................................... 2
Configuring And Calculating Mesh ............... 9
Step 3: Defining The Materials ......................... 3
Step 9: Computing Results .............................. 9
Defining Material Properties ......................... 3
Compute ...................................................... 9
Step 4: Creating Geometry .............................. 3
Step 10: Interpreting Results ......................... 10
Creating The External Box ........................... 3
Displaying The Results .............................. 10
Step 5: Excavating ........................................... 3
Total Displacement .................................... 11
Creating The Twin Tunnel Excavations ........ 3
Creating The Cross Tunnel Profile ............... 4
Orienting The Cross Tunnel Profile .............. 5
Extruding The Cross Tunnel ......................... 6
Cleaning Up The Geometry .......................... 6
Dividing All Geometry ................................... 7
Tutorial Key Concepts
Excavation of diagonal cross tunnel profile
Gravity field stress
Tutorial 4: RS3 1
Step 1: Starting the Model
CRE ATING A BLANK DOCUMENT
New
Project
Start RS3 by selecting Programs  Rocscience  RS3 2.0  RS3 from the Windows
start menu. RS3 opens to a blank screen, which allows you to create a new model by
pressing the [New Project] button. If the RS3 application window is not already
maximized, maximize it now such that the full screen space is available for use.
First, save as Tutorial 04 Cross Tunnel.rs3dmodel: File  Save.
Save
Step 2: Editing the Project Settings
CONFIGURING THE UNITS
Project
Settings
The Project Settings dialog is used to configure the main analysis parameters for your
RS3 model. Open the dialog through File  Project Settings. This will open the dialog
on the first tab: [Units], and set Units = Metric, stress as MPa.
Project
Settings:
Units
OTHER OPTIONS
Next, select the [Groundwater] tab.
Project
Settings:
Ground
water
Enter Method = None. Do not change any other settings. Select [OK] to close the
dialog.
Go to File  Project Summary and enter Cross Tunnel as the Project Title. Select [OK]
to close the dialog.
Tutorial 4: RS3 2
Step 3: Defining the Materials
DEFINING MATERIAL PROPERTIES
Under the same tab (Geology or Excavations) you can assign the materials and
properties of our model through Materials  Define Materials.
Define
Materials
Enter the following properties for “Material 1” in the [Strength] tab.
Material 1
Properties:
Strength
Enter Name = Rock, Initial Element Loading = Field Stress & Body Force, then [OK].
Step 4: Creating Geometry
CRE ATING THE EXTERNAL BOX
Ensure the Geology tab is selected from the workflow at the top of the screen.
Select: Geometry  Create External Box.
A Create External dialog will open, enter First Corner (x, y, z) = (0, 0, 0), Second Corner
(x, y, z) = (90, 62, -60), and Auto-Expand by = 0, then press [OK].
Create
External
Step 5: Excavating
CRE ATING THE TWIN TUNNEL EXCAV ATIONS
Select the Excavations tab from the workflow at the top of the screen. We will now
design the surface and underground excavations.
Create
Cylinder
To make the underground excavation, select: Geometry  3D Primitive Geometry 
Cylinder.
Tutorial 4: RS3 3
Set the Axis Start Point (x, y, z) = (30, 63, -30), End point = (30, -1, -30), Radius = 4,
and Subdivisions = 30, then press [OK].
Create
Cylinder
Create the second tunnel by selecting Geometry  3D Primitive Geometry  Cylinder.
Create
Cylinder
Set the Axis Start Point (x, y, z) = (60, 63, -30), End point = (60, -1, -30), Radius = 4,
and Subdivisions = 30, then press [OK].
CRE ATING THE CROSS TUNNEL PROFILE
Tunnel
Profiler
Lastly, create the connecting tunnel, select Geometry  RS Tools  Tunnel Profile.
The Tunnel Profiler dialog should open. Within the dialog, select the [Square Cavern]
for tunnel shape.
Set the Horizontal Center = 45, Vertical Center = 30, Radius = 1, Overall Height to
Corners = 2, Width = 2, then press [OK].
Tunnel
Profiler
Create
Polygon
from
Polyline
This then created a polyline in the shape of the tunnel profile, so we must convert it to a
filled shape, select “Square Cavern Tunnel Profile” in the visibility pane, then press:
Geometry  Draw Tools  Create Polygon from Polyline. A Create Polygons dialog
will appear with “Square Cavern Tunnel Profile” listed, press [Create Polygons]. This
will transform to “Polygon 0” in the visibility pane.
Tutorial 4: RS3 4
ORIENTING THE CROSS TUNNEL PROFILE
The Tunnel Profiler created the tunnel oriented with the base along the x-axis, but we
want it to have its base on the y-axis.
Rotate
Geometry
In the Visibility Pane, select “Polygon 0”, then rotate it by selecting Geometry 
Transform  Rotate.
We want to rotate the created tunnel around the z-axis about its center. To do so, enter
the following in the dialog:
Rotate
Geometry
Enter Fix (x, y, z) = (45, 30, 0), Axis: (x, y, z) = (0, 0, 1), Angle = 90 Degrees, [OK].
The Tunnel Profiler created the tunnel on XY plane, but in this case, we want it on the
XZ plane, so we must rotate it.
Rotate
Geometry
In the Visibility Pane, select “Polygon 0_prime”, then rotate it by selecting Geometry 
Transform  Rotate.
We want to rotate the created tunnel around the y-axis about the origin. We want it to
end between the twin tunnels, and to do so, it must be rotated about a specific point
referenced to origin. To do so, enter the following in the dialog:
Enter Fix (x, y, z) = (30, 30, -15), Axis: (x, y, z) = (0, 1, 0), Angle = 90 Degrees, [OK].
Rotate
Geometry
Lastly we want the cross tunnel to be on an angle, so in the Visibility Pane, select
“Polygon 0_prime_prime”, then rotate it by selecting Geometry  Transform  Rotate.
We want to rotate it in plan view, so enter Fix (x, y, z) = (45, 30, -30), Axis: (x, y, z) = (0,
0, 1), Angle = 20 Degrees, [OK].
Tutorial 4: RS3 5
EXTRUDING THE CROSS TUNNEL
Now we must extrude the excavated area and define the boundaries.
Extrude
Geometry
Select “Polygon 0_prime_prime_prime” to indicate the object to be extruded, then
extrude by selecting Geometry  Extrude/Sweep/Loft Tools  Extrude.
Enter the following and press [OK] to create the excavated tunnel.
Extrude
Geometry
Enter Offset = -15, Depth = 30, press [OK].
CLE ANING UP THE GEOMETRY
Copy
Geometry
Note
In order to get rid of the extra cross tunnel pieces inside the twin tunnels, we
need a copy of both tunnels to subtract from the cross tunnel. The Subtract
Boolean operation eliminates the Splitter body (the copied twin tunnels) and
keeps the remaining Volume to Split (the cross tunnel).
Select the twin tunnels in the visibility pane, and select: Geometry  Copy Geometry,
keeping all defaults except Spacing = 0, (the Total Copies = 2) press [OK].
Tutorial 4: RS3 6
Copy Entity
Your visibility pane should now have the following entities:
Subtract
Subtract
Next, select one copy of the left tunnel and the cross tunnel in the visibility pane to cut
the excess left end of the cross tunnel by pressing: Geometry  3D Boolean 
Subtract. The left tunnel should be the splitter, and the cross tunnel the volume to split.
Repeat this process with one copy of the right tunnel and the newly cut-into cross
tunnel. Geometry  3D Boolean  Subtract. Set the right tunnel as the splitter, and the
cross tunnel as the volume to split. Now the cross tunnel should fit perfectly to the
curves of the twin tunnels where they intersect. The visibility pane should now have one
of everything: 1 external box, 1 left twin tunnel, 1 right twin tunnel, and 1 cross tunnel.
DIVIDING ALL GEOMETRY
Divide All
Geometry
Make sure all three tunnels when selected in the visibility pane have the role Excavation
in the properties pane. Now we can cut into the external box with the surface load spot
and excavations: Geometry  3D Boolean  Divide All Geometry.
Select all excavation bodies in the visibility pane, and in the properties pane change
their Applied Property = No Material. Your model should now look like the following.
Tutorial 4: RS3 7
Current
State of
Model
Step 6: Adding Stress Loading
APPLYING FIELD STRESS TO THE MODEL
Next, go to the Loads tab. This tab allows you to edit the loading conditions. Select:
Loading  Field Stress.
Field Stress
Field Stress
Enter Field Stress Type = Gravity, the rest should be default (check screenshot), [OK].
Step 7: Setting Boundary Conditions
ADDING MODEL RESTRAINTS
Move to the Restraints tab to assign restraints to the external boundary of the model.
Auto
Restrain
(Surface)
RS3 has a built in “Auto Restrain” tool for use on underground models. Select:
Restraints  Auto Restrain (Surface).
This completes the construction of the model (in terms of geometry).
Tutorial 4: RS3 8
Step 8: Meshing
CONFIGURING AND CALCULATING MESH
Mesh
Settings
Next, move to the Mesh tab. Here we may specify the mesh type and discretization
density for our model. For this tutorial, we will use a 10-node finite element mesh type.
This is not the default mesh parameter so we will need to customize the mesh: Mesh 
Mesh Settings.
The Mesh Settings dialog appears. This dialog allows you to customize parameters of
your mesh. We want to use a graded, 10-noded element mesh.
Mesh
Settings
Enter Element Type = 10-Noded Tetrahedra, Mesh Gradation = Graded, [OK].
Mesh
Then mesh the model: Mesh  Mesh. The model with the generated mesh should look
like the one below.
Model with
completed
mesh
Step 9: Computing Results
COMPUTE
Save
Next, move to the Compute tab. From this tab we can compute the results of our model.
First, save the model: File  Save.
Use the Save As dialog to save the file. Next, you need to save the compute file: File 
Save Compute File. You are now ready to compute the results.
Compute
Select: Compute  Compute.
Tutorial 4: RS3 9
Compute
Engine
Step 10: Interpreting Results
DISPLAYING THE RESULTS
Next, move to the Results tab. From this tab we can analyze the results of our model.
First, refresh the results: Interpret  Refresh Results.
Refresh
Results
On the top right corner of the Results tab, you should see two drop down menus:
Note
The “Element” drop down menu allows you to view the results for solids, bolts,
and liners. For this tutorial we can only view results for Solids.
Excavation
Contour
We will analyze a number of different “Data Type” results. Let’s turn on the exterior
contours so we can see some results: Interpret  Show Excavation Contour.
We also want to define a plan that goes through the slanted cross tunnel. First we must
define a plane, Interpret  XY Plane. In the Create Plane dialog, enter: Plane Origin (x,
y, z) = (45, 30, -30), Plane Normal (x, y, z) = (-0.342, 0.939, 0), then press [OK].
XY Plane
Tutorial 4: RS3 10
Create
Plane
TOTAL DISPLACEMENT
In the top right corner of the Results tab, ensure Element = Solids, and change data
type = Total Displacement:
The Total Displacement results are shown below.
Solids Total
Displ
Other results are available to view as well. Thank you, this concludes the tutorial.
Tutorial 4: RS3 11