Create/Edit Knuckle

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Introduction

The Create/Edit Knuckles command is a powerful routine to automate the creation of localised road widenings, including the following processes:

• Create New
  • Use simple parametric inputs to generate/update an alignment for the knuckle, including match in to the edge of the roadway to which it connects
  • Assign a cross section (Template) as part of the vertical design
  • Assign vertical controls to 'read in' the road levels and apply them to parts of the knuckle
  • Generate a profile that is automatically and continuously matched to the shape and levels of the Road to which it connects
• Edit Existing
  • Adjust horizontal inputs to update the knuckle alignment, whilst maintaining connectivity to the Road
  • Edit the connecting road and the extent of automatic profile matching to the connecting Road

Once created the Knuckle profile can be edited immediately via the Vertical Grading Editor, and users can make additional edits to the knuckle profile via the Create/Edit Roads command.

Special Notes on Knuckle Templates - Template Details.

Main Processes

The main process for creating/editing a knuckle is as follows:

1. Establish the knuckle name, definition and connectivity
2. Set the knuckle horizontal geometry parameters
3. Create/Update the knuckle (alignment) geometry
4. Set profile controls for the knuckle interaction with the adjacent Road

Form Interface

The form is separated into three parts:

• Left side.  This is the inputs area
• Right top section.  This is a dynamic graphics window (and text box) which will update as the user hovers over each input.  It provides a visual description of what the input means
• Right Bottom section.  Create the alignment and string for the knuckle.

 

Details

This command can be used to Create as well as Edit a knuckle.  The form suppresses some functionality in the edit mode.

Special Notes:	Designers must first create the Road to which the knuckle is connected.  Use the Create/Edit Roads command to first create and profile the incoming Road.
	If a user alignment is specified, it is recommended to create this in the same direction as the Road String to which it is being connected.

Creating a Knuckle - Starting the Command

Upon starting the command the command prompt reads:

Select knuckle to edit [Enter if creating a new knuckle alignment]

Options are:

• Creating a NEW knuckle: Press the [Enter] button on the keyboard
• Editing an existing knuckle: click on or near to the alignment in the drawing

Display Components

Once the alignment is selected or the [Enter] button is pressed, the following form is displayed:

Knuckle Name	This is the name that will be assigned to the new knuckle object created in Civil Site Design, as well as the name of the Alignment that will be created. Note: This field will be non-editable when editing a created Knuckle alignment/string.
Select Adjacent Road	Use the pick list to select a Road for the knuckle to connect to.
Match to Code	Civil Site Design automates the horizontal alignment creation of the knuckles (except for Use Alignment) by locating a particular Code from the Road on either the left or right side.  This Code normally defines the edge of the roadway, and sets where the knuckle alignment should connect. Use the pick list to select the appropriate Code from the incoming Road cross section.
Alignment Geometry	Establish the alignment geometry for the knuckle
Type: Knuckle 1	Create a knuckle consisting of three radii and with a start/end chainage Geometry Details Set the geometry for this Type    Start Chainage Type in the Chainage on the Main Road to Start/End the kerb alignment.  Click on the icon to select the location from the screen    End Chainage Type in the Chainage on the Side Road to End/Start the kerb alignment.  Click on the icon to select the location from the screen    Radius 1 First radius of the knuckle    Radius 2 Second radius (center arc) of the knuckl    Radius 3 Third radius of the knuckle    Apply to Left/Right Side  Use the radio buttons to select whether the knuckle is positioned left or right of the Adjacent Road centreline.
Type: Knuckle 2	Create a knuckle by selecting a centrepoint position for the mid-section arc, then entry/exit arcs and tangents connecting between the arcs Geometry Details Set the geometry for this Type    Centre Point Users can type in the centre point coordinates of the mid section arc (Radius 2).  Click on the icon to select a circle or arc in the drawing to set the centre point coordinates    End Chainage Type in the Chainage on the Side Road to End/Start the kerb alignment.  Click on the icon to select the location from the screen    Radius 1 First radius of the knuckle (approach)    Tangent Length 1 Type in a Tangent length.  Leave at 0 to omit a tangent.    Radius 2 Second radius (center arc) of the knuckle    Tangent Length 2 Type in a Tangent length.  Leave at 0 to omit a tangent.    Radius 3 Third radius of the knuckle (return)    Apply to Left/Right Side  Use the radio buttons to select whether the knuckle is positioned left or right of the Adjacent Road centreline.
Type: Knuckle 3	Create a knuckle by selecting a centrepoint position for the mid-section arc, then entry/exit arcs and tangents connecting between the arcs Geometry Details Set the geometry for this Type    Radius 1 First radius of the knuckle (approach)    Tangent Length 1 Type in a Tangent length.  Leave at 0 to omit a tangent.    Radius 2 Second radius (center arc) of the knuckle    Tangent Length 2 Type in a Tangent length.  Leave at 0 to omit a tangent.    Radius 3 Third radius of the knuckle (return)    Offset Chainage Position measured along the Adjacent Road, for the location where the knuckle is at it's maximum offset (parallel to the Adjacent Road centreline).  Click on the icon to select the distance along the Adjacent Road from the drawing.  For a symmetric knuckle, this position will match with the centrepoint of Radius 2.    Move Halfway on Arc If the Knuckle is positioned on a curve on the Adjacent Road (as set by the Offset Chainage) then this will set the knuckle midpoint to match exactly to the half way distance along the curve.    Offset  Type the maximum offset to apply to the knuckle, measured perpendicular to the Adjacent Road centreline at the calculated Offset Chainage    Apply to Left/Right Side  Use the radio buttons to select whether the knuckle is positioned left or right of the Adjacent Road centreline.
Type: Use Alignment	Create a knuckle by using a manually created alignment in the drawing. Geometry Details Set the geometry for this Type    Alignment Name Pick an alignment in the drawing.  The alignment should be created in the same direction as the Adjacent Road alignment and be positioned to match to the Match to Code.
String Creation	After the Alignment has been created (after pressing the Create/Update Alignment button on this form) users can establish controls for turning the Knuckle alignment into a String
Section Template	Use the pick list to select a Template for the creation of cross sections in the knuckle.
Section Spacing	Type in a value for the spacing between calculated cross sections for the knucle string
Widening Options	Establish controls for how the Knuckle String is used to control the Adjacent Road cross sections
Keep the 'Match to Code' and add a new Code (LNUK/RNUK)xc	Over the chainage range of the knuckle, removes all Codes of the Adjacent Road from the 'Match to Code' outwards.  Creates a code (LNUK/RNUK pending the side of the Adjacent Road) and automatically connects this code to the Knuckle String centreline.  Note: If the subgrade for the road does not display correctly, then the designer may have use the "Subgrade by Labels" option on the template editor.  The automatic label that is created is LNUK or RNUK (depending on which side of the road the knuckle is located).  For more information click here.
Set 'Match to Coode' to use Knuckle Vertical Design	Over the chainage range of the knuckle, removes all Codes of the Adjacent Road from the 'Match to Code' outwards.  The 'Match to Code' on the Adjacent Road automatically connects to the Knuckle String centreline.
None	The Adjacent Road will not be adjusted to accommodate the knuckle.  Users can then manually establish how the Adjacent Road should adjust (if at all) for the Knuckle inclusion.
Calculate Knuckle Profile	Automate the vertical design of the knuckle (beyond the start/end connection elevations being set by the Adjacent Road 'Match to Code' elevations
Tick Box: Calculate knuckle profile using adjacent road string	If ticked on, vertical IP's can be automatically created on the Knuckle String (at the selected Section Spacing) to adopt elevations referenced to the Adjacent Road string).
Distance to calculate levels from start	A distance, measured along the Adjacent Road from the Start position on the Adjacent Road, to automatically insert vertical IP's on the knuckle string.  Elevations will be calculated by projecting the crossfall of the Adjacent Road 'Match to Code' out to the Knuckle offset (users can elect to transfer the same crossfall or reverse crossfall to the Knuckle string)
Distance to calculate levels from end	A distance, measured along the Adjacent Road from the End position on the Adjacent Road, to automatically insert vertical IP's on the knuckle string.  Elevations will be calculated by projecting the crossfall of the Adjacent Road 'Match to Code' out to the Knuckle offset (users can elect to transfer the same crossfall or reverse crossfall to the Knuckle string)
Fit Vertical Curves	Tick on to automatically design the vertical design of the knuckle between the automatically inserted vertical IP's.  This will insert either 1 vertical curve that matches the incoming/outgoing grades for the full length between the vertical IP's, or two equal length vertical curves adopting the incoming/outgoing grades with total length measuring the full length between the vertical IP's. Untick to adopt a single tangent between the automatically inserted vertical IP's.
Reverse Slope	Applies to the 'Distance to calculate levels' inputs. Tick on to use the elevations of the 'Match to Code' on the Adjacent Road and apply the REVERSE crossfall calculated to the 'Match to Code' (if the crossfall to the 'Match to Code' is -3%, then a +3% crossfall would be used to calculate elevations for vertical IP's on the Knuckle String Tick off to use the elevations of the 'Match to Code' on the Adjacent Road and apply the same crossfall calculated to the 'Match to Code' (if the crossfall to the 'Match to Code' is -3%, then a -3% crossfall would be used to calculate elevations for vertical IP's on the Knuckle String
Hover Image	This window will update based on the hover location of the mouse on the form.
Help Text Box	Provides information about the option under the mouse hover position.
Create/Update Alignment	Click to generate an Alignment for the Knuckle based on the displayed Knuckle design parameters and connection details defined at the top of the form.  This will create an Alignment connected to the selected Road at the specified connection point at the start and end of the Knuckle alignment (for Use Alignment, the designer is required to ensure connection of the alignment start/end to the Match Code). Note: The initial display and label style applied (when the alignment is created) is set from the Active Drawing Settings form. If the geometry does not enable creation of a knuckle alignment an error message will display. If the alignment is not appearing as desired, simply change the parameters defining the horizontal geometry and click on the Create/Update Alignment button again to recreate the alignment.
Create/Update String	Creates/Updates the Knuckle String.  The string will be created, the Adjacent Road edited as per the Widening options and, if created, the Auto Model (TotalModel) surface will be updated.
Set Section Widths	Override the default section widths that apply to the knuckle Left Width When viewing cross sections and for sampling the 'existing surface' elevations for calculating the batter position Right Width When viewing cross sections and for sampling the 'existing surface' elevations for calculating the batter position OK Save and exit Cancel Exit without applying changes.
Show VGE on Close	If ticked on, when the form is closed the Vertical Grading Editor for the Knuckle String will open, allowing for redesign vertically and adjustments to cross sections.
Close	Click to close the form.
Zoom/Pan	Click to allow zoom/pan in the drawing using the middle mouse button.  Press [enter], [esc] or left click the mouse button to return to the form.