Construction Lines
Description
This form is used to define lines in the 2D Sub Model plane. The lines are generally straight. However, when defined by offset to a curved design line or setting out line they may be curved. Construction lines are useful because their intersections frequently define structure corners or other locations that can be graphically selected in building the structure geometry (using the 'Intersect' Snap Mode).
A comprehensive list of options for generating construction lines relative to the design lines, setting out lines or the basic easting / northing grid is available for selection in the Line Types field.
Outline Procedure
This form may be accessed by selecting the Structure Definition Group Button in the Explorer Panel. If the 2D Sub Model group already contains a 'Construction Lines' item then click on it. If no construction lines have yet been defined for the Sub Model group then (i) ensure that the Active Group Item is in the relevant Sub Model, (ii) click Setting Out | Construction Lines on the contextual tab (or from the Navigation Pane toolbar in the classic interface).
First make a selection from the field labelled 'Line Types'. For construction lines positioned relative to design lines or setting out lines, the appropriate design line must then be selected, either from the third column of the table, or by clicking with the mouse over the required design line or setting out line in the graphics window. Depending on the type of construction line, the appropriate offset, chainage and/or angle must then be defined (inappropriate fields are non-editable). The easting or northing for lines along the grid are entered in the 'Offset' column. Design line and setting out line offsets are positive to the right of the line (looking from start to end) and negative to the left.
For details of the table features, and navigation, see the help topic Table Features & Navigation.
Form Graphic
Field Help
Line Types
Construction lines are set out relative to Design Lines or Setting Out Lines or the global coordinate axes.
On making a selection from this field a new default construction line of the appropriate type is added to the table. If the selection was for a construction line relative to a Design Line or Setting Out Line then the appropriate Design or Setting Out line must now be selected (either from the list in the third column of the table or by graphic pick).
Pressing the Delete key removes the construction line from the active row.
Ref.
Display only - not editable.
Type
The Line Type, selected from the 'Line Types' field, of this construction line.
Display only - not editable.
DL/SOL Ref
For construction lines that are set out relative to a Design Line or Setting Out Line, the appropriate Design or Setting Out Line may be selected from this field. Alternatively, when the cursor is in the required row of the table, point with the mouse to a Design Line or Setting Out Line in the graphics window to associate the construction line with that Design or Setting Out Line.
Offset
For construction lines that are set out relative to a Design Line or Setting Out Line, the distance by which the construction line is offset from the Design or Setting Out Line is entered in this field.
'Offset' values are positive on the right side of the Design or Setting Out Line, and negative on the left side of the Design or Setting Out Line, when looking from the start point of the Design or Setting Out Line towards the end point.
For construction lines that are set out as a graticule of the global coordinate system, the value of the Easting (X) or Northing (Y) as appropriate is entered in this field.
Chainage
This field applies only to construction lines perpendicular to or at an angle to the reference Design line or Setting Out Line. In the case of 'Offset at Angle', this chainage and the offset together give a point through which the construction line passes. The Home and End keys can be used to set the chainage to the start or end value whilst this field is in editing mode.
Angle
The angle of the construction line, measured anti-clockwise to the direction of the reference Design or Setting Out Line.