Application	PLAXIS 2D PLAXIS 3D
Version	PLAXIS 2D 2023.2 PLAXIS 3D 2023.2
Date created	23 May 2017
Date modified	17 October 2023

Description

The following article gives information on how to use the Remote scripting feature to create a tunnel using the PLAXIS tunnel designer.

In this example, we will show the Python commands to generate the tunnel cross-section in both PLAXIS 2D and PLAXIS 3D, based on the geometry of the PLAXIS 2D Tutorial Lesson - Excavation of a NATM tunnel [link].

The PLAXIS 2D geometry of the NATM tunnel in the tutorial lesson

To better understand the structure of the commands used in the example, some are explained below:

set command
- set is used in PLAXIS Input to set one or more properties of one or more objects. An example is the following:
```
set Tunnel_1.CrossSection.Segments[0].ArcProperties.Radius 10.4
```
  With Python, the set command can be written using the assignment statement set command
  (name = expression):
```
g_i.Tunnel_1.CrossSection.Segments[1].ArcProperties.Radius = 10.4
```
commands with no parameters
- In PLAXIS Input some of the commands do not have any parameters defined (as optional). One case is the following command as it is generated in the Input program:
```
add Tunnel_1.CrossSection
```
  With Python, the command can be written in the following way:
```
g_i.Tunnel_1.CrossSection.add()
```
  Note that the empty field in the parentheses indicates that there are no parameters defined for this method (command).

PLAXIS 2D - NATM tunnel (Python commands)

# define the tunnel and assign a variable to it
tunnel = g_i.tunnel(0, 16)

# first segment defined command by command
tunnel.CrossSection.add()
tunnel.CrossSection.Segments[-1].SegmentType = "Arc"
tunnel.CrossSection.Segments[-1].ArcProperties.Radius = 10.4
tunnel.CrossSection.Segments[-1].ArcProperties.CentralAngle = 22

# function for the rest of segments
def add_arc(tunnel, radius, angle):
    segment = tunnel.CrossSection.add()
    segment.SegmentType = "Arc"
    segment.ArcProperties.Radius = radius
    segment.ArcProperties.CentralAngle = angle

# call the function to create two more segments
add_arc(g_i.Tunnels[-1], 2.4, 47)
add_arc(g_i.Tunnels[-1], 5.8, 50)

# extend to symmetry axis and symmetrically close the shape
tunnel.CrossSection.extendtosymmetryaxis()
tunnel.CrossSection.symmetricclose()


# add subsections
subsection, subsection_segment = tunnel.CrossSection.addsubcurve()
subsection.Offset2 = 3
subsection_segment.SegmentType = "Arc"
subsection_segment.ArcProperties.Radius = 11
subsection_segment.ArcProperties.CentralAngle = 360

# create a list for all segments and subsections that will be intersected
segments_subsections = []
for subsection in tunnel.CrossSection.Subsections[:]:
    segments_subsections.append(subsection)
    for segment in tunnel.CrossSection.Segments[:]:
        segments_subsections.append(segment)

# intersect the created list and delete the odd one
tunnel.CrossSection.intersectsegments(*segments_subsections)
tunnel.CrossSection.delete(tunnel.CrossSection.Subsections[2])

# define plates for slice polycurves, assign material, create negative interface
for tunnel_slice in tunnel.SliceSegments[:]:
    g_i.plate(tunnel_slice)
    # next command requires a material to be predefined for the lining
    tunnel_slice.Plate.Material = g_i.Lining
    if tunnel_slice == tunnel.SliceSegments[4] or tunnel_slice == tunnel.SliceSegments[5]:
        pass
    else:
        g_i.neginterface(tunnel_slice)


# generate the tunnel
g_i.generatetunnel(tunnel)

PLAXIS 3D - NATM tunnel (Python commands)

# define the tunnel and assign a variable to it
tunnel = g_i.tunnel(0, 0, 0, 1, 0, 0, 0, 0, 1)

# first segment defined command by command
tunnel.CrossSection.add()
tunnel.CrossSection.Segments[-1].SegmentType = "Arc"
tunnel.CrossSection.Segments[-1].ArcProperties.Radius = 10.4
tunnel.CrossSection.Segments[-1].ArcProperties.CentralAngle = 22

# function for the rest of segments
def add_arc(tunnel, radius, angle):
    segment = tunnel.CrossSection.add()
    segment.SegmentType = "Arc"
    segment.ArcProperties.Radius = radius
    segment.ArcProperties.CentralAngle = angle

# call the function to create two more segments
add_arc(g_i.Tunnels[-1], 2.4, 47)
add_arc(g_i.Tunnels[-1], 5.8, 50)

# extend to symmetry axis and symmetrically close the shape
tunnel.CrossSection.extendtosymmetryaxis()
tunnel.CrossSection.symmetricclose()


# add subsections
subsection, subsection_segment = tunnel.CrossSection.addsubcurve()
subsection.Offset2 = 3
subsection_segment.SegmentType = "Arc"
subsection_segment.ArcProperties.Radius = 11
subsection_segment.ArcProperties.CentralAngle = 360

# create a list for all segments and subsections that will be intersected
segments_subsections = []
for subsection in tunnel.CrossSection.Subsections[:]:
    segments_subsections.append(subsection)
    for segment in tunnel.CrossSection.Segments[:]:
        segments_subsections.append(segment)

# intersect the created list and delete the odd one
tunnel.CrossSection.intersectsegments(*segments_subsections)
tunnel.CrossSection.delete(tunnel.CrossSection.Subsections[2])

# define plates for slice surfaces, assign material, create negative interface
for tunnel_slice in tunnel.SliceSurfaces[:]:
    g_i.plate(tunnel_slice)
    # next command requires a material to be predefined for the lining
    tunnel_slice.Plate.Material = g_i.Lining
    if tunnel_slice == tunnel.SliceSurfaces[4] or tunnel_slice == tunnel.SliceSurfaces[5]:
        pass
    else:
        g_i.neginterface(tunnel_slice)



# define a trajectory for the tunnel
tunnel.Trajectory.add()

tunnel.Trajectory.Segments[0].LineProperties.Length = 12

# generate the tunnel

tunnel.regeneratetunnelphases()

g_i.generatetunnel(tunnel)

The goal of this example is to show how to use Python to create a tunnel in PLAXIS 2D and PLAXIS 3D: its focus is on geometry creation. To run this script, a plate material (named Lining) already needs to be defined in the current project.

How to create a tunnel using Python

Description

PLAXIS 2D - NATM tunnel (Python commands)

PLAXIS 3D - NATM tunnel (Python commands)

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