Creating or Splitting a Road/Railway Earthwork

You can prepare the design of a road or railway, or a portion of it, by using or creating typical cross sections, by adapting the cross section to an existing terrain. You can also split earthwork geometries to avoid clash with other geometries such as intersecting roads or bridge abutments.

Note: It is possible to modify a same terrain by several road or railway stretches from different road or railway surfaces by selecting the same Stretch Set of the Road/Railway Earthwork dialog box.

For information about object types, see Building and Civil Assemblies User's Guide: Defining Object Types.

To help you find the reference information you need to use the content delivered along with your app, you can consult the 3DEXPERIENCE Native Apps Content User's Guide.

This task shows you how to:

Before you begin:
  1. If a terrain exists, it must be polyhedral. For more information, see Working with Polyhedral Entities in Civil Engineering 3D Design.
  2. Optionally, create a typical cross section object type that is the input data necessary for the road or railway surface creation. With the Typical Cross Section command, a specialized sketch is created, called Typical Cross Section. It contains one or two profiles tagged respectively as filling profile and excavation profile. See Creating a UDF- or Sketch-based Typical Cross Section and Associated Object Types for Earthworks.
The app optional content is not automatically installed along with the code. Contact your administrator if you must install the files you need. For more information, see Install Optional Content. You can also see Installation and Setup:Install: 3DEXPERIENCE Platform: Installing 3DEXPERIENCE Platform Services for the First Time: Installing Services One-by-One: Native Apps: Installing Native Apps: Installing a Native App.
See Also
About Typical Cross Section

Design a Road or Railway Earthwork

You can design a road or railway earthwork by using or creating typical cross sections, by adapting the cross section to an existing terrain.

  1. From the Civil Engineering section of the action bar, click Road Earthwork or Railway Earthwork to make a design of a road or railway on a terrain.

    The Road Stretch or Railway Stretch node is renamed. It appears in the tree and contains these features:

    1. Common Stretch: The terrain must be polyhedral. For more information, see Creating a Horizontal Alignment and Creating a Vertical Alignment.
    2. Filling Stretch: The geometry that is added on the ground.
    3. Excavation Stretch: The geometry that is removed from the ground.

      If you use the Road/Rail Subgrade Design command, you can add excavation and filling profiles in the subgrade cross section. For more information, see Creating or Splitting the Subgrade Layer of an Infrastructure.

  2. Select a 3DEXPERIENCE road or railway surface feature, or any other surfaces.

    If you select a 3DEXPERIENCE road or railway surface feature, the alignment of the selected surface is automatically selected.

    For other surfaces, it must contain 4 sides, based on the following criterion:

    • If the angle between two consecutive edges of the surface boundary, projected on the XY plane, is less than 45 degrees, these two edges are considered as continuous.
    • The surface of Fig.1 contains only 3 sides, it is invalid.
    • The surface of Fig.2 contains more than 5 sides, it is invalid.
    • The surface of Fig.3, when it contains more than 4 edges, based on the above criterion, it can be broken into 4 sides, and therefore become valid.

  3. Optional: Select a terrain in the tree or the 3D area.
    Note: You can select a modified terrain as input to create a new modified terrain.
  4. Optional: Select an alignment.

    If the selected surface is a 3DEXPERIENCE road or railway surface feature, the alignment is displayed, its editor is disabled, and you cannot select another 3D alignment.

    Otherwise, you can select any nonclosed curve, or an edge of the input surface as an alignment curve.

    The input curve determines the road orientation, with its left and right sides based on road orientation. Here are specific cases about the selection of surface elements:

    The start and end point of the input curve is on one side:

    		When you select an edge of the input surface, the selected side is considered as the right side. The other sides are deduced automatically. The orientation of the input curve is ignored.
    There is one intersection point with one side, and another intersection point on the opposite side:

    • Side, which is near to the curve start extremity is the start side.
    The other sides are shown above.
    There is only one intersection point with one side:

    • The intersecting side is used as either the start or end side.
    • If the start extremity of the input side is outside the surface (there is no projection of the curve start extremity on the surface in the Z direction) then it is the start side. Otherwise, it is end side.
    There is no intersection:

    • In this case, the side that is most parallel to the input curve is used as the left or right side.
    • The orientation of the input curve determines which is the right side.

    The other sides are determined automatically.

    There is an input curve, and it does not correspond to the above cases: -
    • The selected point must lie on the surface boundary.
    • If the start element lies inside a side of the road surface, this side is used as the start side.
    • If it is on the corner of two sides, then the shortest side is used as the start element.

    The other sides are automatically determined, based on the general rule.

    If the alignment curve is selected, you can select the start and end elements to limit the road design between them. The start and end elements must lie on the alignment curve.

    If the alignment curve is not selected, you can only select a start point which must lie on the boundary of the input surface. You cannot select the end point.

    In the following case, the input curve is invalid, as shown in the figure below:

    • A curve cannot intersect one side more than once.
    • A curve cannot intersect more than two sides.
    • A curve cannot intersect two consecutive sides.


  5. Optional: Select the start and end elements in the tree or the 3D area.
  6. Select the Object Type of a cross section by clicking Search an Object Type in the Typical Cross Section field.

    Only object types corresponding to the chosen discipline (which can be a platform, a road, or a railway) and undefined object types are visible. The content provided in the SubgradeTypicalCrossSections.3dxml stored in the ...\startup\Civil\Alignment directory has been updated in R2022x GA to take the discipline into account.



    To remove the cross section, click .

    The cross section can be based on an alignment sketch, or on a user-defined feature (UDF). If the object type contains two cross sections, one defined with the alignment sketch, the other with the UDF, the cross section defined with the alignment sketch is used.

    If the cross section is UDF-based and has geometrical inputs named Base Surface or Base Alignment, the input surface of the earthwork is automatically assigned to the UDF input called Base Surface. The input alignment is automatically assigned to the UDF input called Base Alignment. You can change these inputs manually.

    If the cross section is a UDF, an option Precision is added in the Parameters area of the Road Earthwork dialog box. Use one of the following computation modes:

    • Coarse: To operate with user-defined cross sections only. This computation mode is quick but less precise.
    • Medium: For a quick but less precise computation.
    • Fine: May be time-consuming.
    • Manual: When selected, the Step box appears under the Precision modes. Set the step value to define the maximum distance between profiles along the alignment. Subgrade and Earthwork surface computation (including Preview) is based on these computed profiles.

      If the Manual precision is used, the alignment is discretized according to the two following parameters:

      • The sag value that defines the chordal deviation that is the maximum distance between a polyline (chord) whose end points lie on a curve, and a point on this curve as illustrated below:

        To specify a sag value, select the check box available next to the Sag box and specify the value. The default sag value is 10mm.

        If the check box is cleared, the discretization is performed using only the step value.

      • The Step value that represents the distance between two successive profiles along the alignment (polyline). Subgrade and Earthwork surface computation (including Preview) may be time-consuming, particularly if the value is low. If the Sag check box is selected, the step value represents the maximum step.

        It is user-defined. Step is useful to add points on linear portions of the alignment.

        The resulting points of the discretization are the defining positions of the profiles before surface generation.

      In manual mode, the discretization takes into account the extremities of internal edges. Therefore, the profiles are positioned on these extremities.

  7. Optional: To display a preview of the selected object type in a side panel, click Template Helper .
    A template viewer opens next to the Road/Railway Earthwork dialog box and displays the shape of the object type and axis systems.

    In the Helper, you can move and zoom in the object type. Click again the same input and the object type moves back to its initial position.

    To close the Helper, click or Close or

  8. If the cross section has not been selected, click Sketch to create a new sketcher-based typical cross section.
    The Typical Cross Section Sketcher opens, allowing you to create the excavation profile and filling profile.
  9. To edit the typical cross section, click the Typical Cross Section box.
    Only the sketcher-based cross section can be edited. The Typical Cross Section Sketcher opens, allowing you to edit excavation profile and filling profile.
  10. If the selected cross section is based on the UDF, select all inputs of the UDF.
  11. To display or edit the typical cross section constraints in the 3D area, click .
    Note: You can edit the dimensions of these constraints in the Constraint Definition dialog box directly in the Civil Engineering 3D Design.
  12. To change the display unit of the angle slope:
    1. Double-click a constraint.
    2. Right-click the Value box in the Constraint Definition window and select Change Display Unit.
    3. Select a Display Unit in the list.
    Notes:
    • This command lets you change only the display unit of the parameter you are creating or editing. To change the display unit for your session, select Me > Preferences > Parameters and Measure > Units. It is available for persistent parameters only.
    • If you enter a value without indicating the unit, the display unit is the one you set in Me > Preferences. The value is immediately modified to take this implicit value into account. If you select U_V as display unit and enter 2:1 , the value is 2U1V. If you later change the display unit to degree, the value is 26.565deg.
    • To reset the unit, select the Reset (use display unit defined in the preferences) contextual command.
    • To change the slope value and unit, enter them directly in the Value box in Constraint Definition with a unit symbol (computation without unit is not supported). For the slope value, you can enter an integer, a real number, or a fraction. If you enter a real number, it is converted into the value closest to the associated fraction, for example:
      • If the input value is 0,25 V_U, you obtain an angle of 1/4 : 1 V_U.
      • If 1,5 : 1 V_U, you obtain 1 1/2 : 1 V_U
      • If 0,33: 1 V_U, you obtain 1/3 : 1 V_U

      Other input formats are not supported and a message appears if you use a decimal separator other than "." or ",". Then the display value or unit is updated in the 3D area (constraint geometry and legend).

  13. To swap the left profile with the right profile of the cross section when the profile is not symmetrical, click .

    This command is available only if the cross section is based on an alignment sketch.

    For a nonsymmetrical typical cross section, as shown in the left figure below, the default result does not always correspond to your expectation.

    With this option you can swap the left and right profiles, as shown in the middle and right figures below:

  14. To extrapolate the last section of the cross section profile to the terrain, select the Extrapolate cross section to terrain option in the Parameters section of the dialog box. By default, this option is selected.
    • The cross section profile is systematically extrapolated to the terrain, as shown in the right figure below.
    • To keep the profile as it is (as shown in the left figure below), without extrapolation, clear the option.

      : Right side profile without extrapolation.

      : Right side profile with extrapolation.

  15. To edit sections, do the following:
    1. Set parameters on sections in the Sections area of the window. By default, there is a start and end section. Each section must have the same number of edges and vertices along the swept volume.
    2. Select the contextual command to display or hide parameters on a section in the 3D area.
    3. Add a new section by clicking and selecting a point on alignment for example. The new section inherits the previous section's parameters. When you have three sections, additional contextual commands are available: Remove and Order sections along the alignment.
  16. To manage transitions between sections, use the following parameters in the Sections area:
    • Enable Transition option: selected by default.
    • Transition Length value.

    If the Enable Transition command is selected, the transition between sections is done on the Transition Length.

    If the Enable Transition command is cleared, the transition between sections is done on the whole distance between sections.

    Notes:

    There is no transition on the first section.

    Transition length must:

    • Not be equal to zero on intermediate sections.
    • Not be greater than the distance between two consecutive sections that may interfere.
    • Be negative or equal to zero on the last section. A null transition on the last section means that it is going to be ignored.

  17. Select a destination stretch set to aggregate the newly created road or railway stretch.
    Notes:
    1. When a linear stretch or a stretch set have been set as current, you can select it in the Destination Set box.
    2. If the stretch set has already been aggregated, you cannot change its destination.
    3. When no terrain is selected, by default no stretch set is selected, and the stretch is created directly under the road or railway node.
    4. If you want to select an existing stretch set into which the current stretch is to be aggregated, first click the “Stretch Set”, then select the stretch set either in the 3D area or in the tree.
    5. Click to create a new road or railway stretch set, and it is aggregated under the Stretch Set in the tree.
    6. Click to remove the selected road or railway stretch set, and the current stretch is created out of any stretch set.
    7. If an existing stretch set or a new stretch set is selected, the following options are selected by default to create a modified terrain and, excavation and filling works in the Stretch Set automatically:
      1. Create modified terrain: if you clear this option, the modified terrain is not created in the Stretch Set. When you select the option, the boundary of excavations and fillings is generated in the tree. If you click the boundary feature in the tree, it is highlighted in the 3D area.
      2. Create excavation and filling works: the excavation and filling works are also not created in the Stretch Set.

    8. If a stretch has been aggregated into a stretch set, you cannot move it outside of the stretch set or into another stretch set.

  18. Optional: To modify the terrain and compute excavation or filling works, select the following options:

    1. If the terrain has not been selected, or if the terrain is selected but no Destination Set has been selected, only a road, railway, or platform stretch is created, without any modification of the terrain.
    2. If the terrain and the Destination Set have been selected:
      1. If the Destination Set does not exist, then a new stretch set is created.
      2. Otherwise, the road, railway, or platform stretch is moved to the existing Destination Set.
      3. If the option Create modified terrain is not selected, the terrain is modified. If not, it is deactivated. By default, the with excavations and fillings option is selected and you can see these modifications encrusted on the terrain:

      4. To modify the terrain and take only earthwork excavation stretches into account in terrain modification, click with excavations: filling stretches are ignored. To modify the terrain and take only earthwork filling stretches into account in terrain modification, click with fillings: excavation stretches are ignored and consequently excavation works are not computed.
      5. To remove the excavations and fillings from the modified terrain, select the without excavations and fillings option:

      6. If you click with only excavations and fillings, the modified terrain contains only excavations and fillings:

      7. If the option Create excavation and filling works is selected, they are created, or modified if they have already been created:

        If not, they are deactivated.

    3. If the Create modified terrain option is selected, the boundary of excavations and fillings is generated under the Stretch Set in the tree. If you select the boundary in the tree, it is highlighted in the 3D area:

    4. To keep or remove the excavation or filling works, which are not connected to the road, railway, or platform surface, select the Keep non-connected excavation and filling works option. When a zone seems to be meaningless for the surface (Zone2 in the example below), you can disconnect it from the road, railway, or platform:

      With this option, Zone2 is excluded from the filling works result.

  19. To visualize the impacts on and under the terrain, click Preview.

    With Preview, all UDF-based cross sections, used in the stretch computation, are displayed.

    The preview displays the cross section in the shape of a sweep along the alignment:



  20. Click OK to create the result.

    The corresponding publications of the excavation and filling works are created, similar to what is done in the Capture Command Specifications command. The Bank Volume extension parameters, in the Ifc Excavation/Filling works base quantities dialog box, are automatically filled in with computed volumes.

    If you hide the Excavation Works and Filling works in the tree, you can see the road or railway following perfectly the shape of the terrain.

Split an Earthwork

You can split earthwork geometries to avoid clash with other geometries such as intersecting roads or bridge abutments.

Before you begin: Your model should contain an earthwork included in a subgrade or a stand-alone earthwork.
  1. In the Road/Railway Earthwork dialog box, select the Split option in the Sections area and a splitting element such as a point, a plane, or a surface in the 3D area.

    The points, planes, and surfaces that meet the following conditions can be selected as input for splitting sections:

    • A plane defined by a point and an angle:
      • The point is projected on the alignment (if it is not on the alignment.)
        The point is on the alignment. Computation of another point when the initial one is not on the alignment.




      • A plane passing by this point and normal to this alignment is built.
      • This plane is rotated around an axis passing by the initial point and along Z.
        Input Result

        When the point is part of the alignment and the plane intersects both sides of the earthwork surface:



        Earthwork

        Alignment

        Angle between 0 degrees and 180 degrees (excluded). If it is equal to 90 degrees, no split is done at the extremities.

        Plane

    • An existing plane or surface:
      • It must have an intersection with the surface of the earthwork.
      • It must have an intersection with the alignment and must be a point (to define its section name with a stationing).

    Once a split element is selected, a dedicated split section line is displayed (example: P0+210 section):

    • Earthwork parameters are not available.
    • The Split option cannot be cleared.
    • The Split angle is only available if the input is a point.
    • A check box entitled Split Other Side is introduced into the Parameters area to choose which side of the earthwork to split.

    The initial earthwork outputs are split. Their features are modified and no new feature is created in the tree.

    The split earthwork surface becomes the input for the calculation of the common, excavation, or filling stretch.

    Only the input common surface is split and, the result common stretch and the excavation and filling stretches are computed again.

  2. Choose a degree for the angle of the split in the Split Angle column.
    The surface (not computed) is an input of a stand-alone earthwork.
  3. To generate a new split, add a new section.
  4. Optional: Modify the split angle for two sections.
  5. To remove a split, right-click a section and select Remove in the Road/Railway Earthwork window.
    You obtain the initial result of the earthwork, without split.

Here is a result of several split operations based on the selection of a plane and a point belonging to the alignment: