Add Support Pressure

Support Pressure can be applied to the slope surface with the Add Support Pressure option. Multiple support pressures can be added and are allowed to overlap in any manner.

To apply a support pressure:

1. Navigate to the Loading & Support workflow tab
2. Select Support > Add Support Pressure.
3. The Add Support Pressure dialog will appear. Enter the Name of the support pressure.
4. Define your support pressure Shape and Properties under the Shape/Property tab:
   • Select support pressure Shape (Rectangular, Circular, or Polygon) and Basepoint.
   • Select Support Pressure Type (Uniform or Non-uniform).
   • Select Force Application (Passive or Active). See the Active and Passive Force Application topic for more information.
   • Set Magnitude and Orientation of the support pressure.
5. Select the location on the model for the support pressure to be applied using the Location tab.
   • Enter a Location (X, Y) and Orientation, or use Freehand Manipulation functionality.
6. Click OK to add the Support Pressure node. The Support Pressure layer is projected downward onto the terrain.

Shape/Property Tab

Define Support Pressure Shape

• Rectangle
  • Width (m) and Height (m)
  • Magnitude (kPa)
  • Load Type (Uniform, Non-Uniform, Elevation)
  • Basepoint (default or custom)
  • Orientation (vector, trend/plunge, normal, local +x, local +y, local +z)
• Circle
  • Radius (m)
  • Load Type (Uniform, Non-Uniform, Elevation)
  • Magnitude (kPa)
  • Basepoint (default or custom)
  • Orientation (vector, trend/plunge, normal, local +x, local +y, local +z)
• Polygon (use table to enter custom coordinates)
  • Basepoint (default or custom)
  • Magnitude (kPa)
  • Orientation (vector, trend/plunge, normal, local +x, local +y, local +z)
  • Coordinates [U(m) and V (m)]

Base Point

The Basepoint is defined relative to a local coordinate system corresponding to the shape of the support pressure area. The Basepoint (u, v) snaps to the Location (x, y) in the global coordinate system. The U and V axes correspond to horizontal and vertical axes in the local shape, which is indicated at the right side of the shape/property dialog.

Orientation

The pressure orientation may be specified using one of the following options:

• Normal - pressure is applied normal to the boundaries
• Local +x - pressure is applied to the boundaries in the positive x-direction (i.e. +x)
• Local +y - pressure is applied to the boundaries in the positive y-direction (i.e. +y)
• Local +z - pressure is applied to the boundaries in the positive z-direction (i.e. +z)
• Vector (x,y,z) - specify a vector from the x, y, and z-directions
• Trend/Plunge - specify a trend and plunge (see Sign Convention for more information)

Location Tab

Location options allow loads to be either placed freehand on the model using the Freehand Manipulation commands or defined by coordinate on the modelling interface.

• Freehand Manipulation: these commands will minimize the Add Support Pressure dialog and allow the user to place the load "Freehand" on the model:
  • Move: move the mouse around the modelling interface and click to place the pressure in the desired location.
  • Rotate: move the mouse to rotate the orientation of the pressure, using the center as the base.
• Numerical Definition:
  • Location: Enter the coordinates to define where the basepoint (previously defined in the Shape/Property tab) of the load will be located on the model.
  • Orientation: Enter an Angle to finalize the pressure definition. The pressure area rotates with respect to the base point.