OverlayLevelCrown

This subassembly overlays an existing crowned carriageway, with a levelling layer added above the existing ground as required.

Attachment

The attachment point is the crown point of the overlay layer with finished ground crossfall.

Input Parameters

Note: Note: All dimensions are in metres or feet unless otherwise noted. All slopes are in run-over-rise form (for example, 4 : 1) unless indicated as a percent slope with a “%” sign.

Parameter Description Type Default (metres or feet)
Crown Offset Positive or negative offset at the crown point Numeric 0.000m (0.00 ft)
Crown Use Profile Options Select to tie the inside edge of overlay to a profile, or adjust crown point level to minimum level depth User Defined Minimum Level Depth
Design Lane Width same as Existing Lane Width
  • Yes

    Specifies that the design lane width is the same as existing lane width

  • No

    Specifies that the design lane width is not the same as existing lane width

    Note: If No is selected, the Inside Edge of Existing Lane and Outside Edge of Existing Lane parameters will not be applied to the subassembly
User defined No
Inside Edge of Existing Left Lane This is the start point for calculating existing ground slope for the left lane Numeric 0.000m (0.00 ft)
Inside Edge of Existing Right Lane This is the start point for calculating existing ground slope for the right lane Numeric 0.000m (0.00 ft)
Outside Edge of Existing Left Lane This is the end point for calculating existing ground slope for the left lane Numeric -12.000m (-12.000 ft)
Outside Edge of Existing Right Lane This is the end point for calculating existing ground slope for the right lane Numeric 12.000m (12.000 ft)
Overlay Depth Depth of the overlay layer Numeric, positive 0.300m (0.300 ft.
Right and Left Overlay Slope Options Specifies right and left overlay slope options
Tip: Flapping is a term used to describe how the Corrected Crossfall for an overlay in a rehab subassembly is calculated. Flapping outcomes are different, relative to the Slope Tolerance and the Slope Difference between existing ground crossfall and ideal crossfall. If the Slope Difference is less than the Slope Tolerance for the subassembly, then the use case is considered 'within tolerance'. If the Slope Difference is greater than the Slope Tolerance for the subassembly, then the use case is considered 'without tolerance'.
Note: Slope Tolerance is an absolute value. Therefore, for either a Slope Difference of 0.4% or -0.4%, both have an absolute value of 0.4%. If the Slope Tolerance is 0.5%, the 0.4% absolute Slope Difference would be considered within tolerance.
  • User Defined with Flapping
    Flapping specifies how the Corrected Crossfall will be calculated, relative to the slope tolerance for the subassembly
    • Flapping Within Tolerance:

      Corrected Crossfall will be set as close as possible to the Existing Ground Crossfall and will also attempt to meet Minimum Level Depth

    • Flapping Without Tolerance:

      Corrected Crossfall will be set as close as possible to the Existing Ground Crossfall within Slope Tolerance

  • User Defined Without Flapping
    Flapping specifies how the Corrected Crossfall will be calculated, relative to Slope Tolerance for the subassembly
    • Flapping Within Tolerance:

      Corrected Crossfall will be set equal to Ideal Crossfall

    • Flapping Without Tolerance:

      Corrected Crossfall will be set as close as possible to the Ideal Crossfall, within Slope Tolerance.

  • Outside/Inside Lane Superelevation
    Outside or Inside Lane Superelevation will replace Ideal Crossfall. Corrected Crossfall values for the overlay layer will be defined by the superelevation table for the section instead of the Ideal Crossfall.
    Note: If Outside/Inside Lane Superelevation is chosen but the alignment for the rehab corridor doesn't have a superelevation table defined, Ideal Crossfall will be used instead.
  • Match Slope

    The Corrected Crossfall is always set equal to Existing Ground Slope

  • Use Ideal Crossfall

    The Corrected Crossfall Slope is always set equal to Ideal Crossfall

User Defined User Defined Without Flapping
Left Ideal Crossfall Specifies user defined Ideal Crossfall for the finished ground profile of the left lane Numeric -2.00%
Left Minimum Level Depth The minimum level depth between the existing surface and the bottom of the left overlay layer Numeric, positive 0.300m (0.300 ft)
Left Slope Tolerance Tolerance for varying the left overlay slope Numeric, positive 0.50%
Right Ideal Crossfall Specifies user defined Ideal Crossfall for the finished ground profile of the right lane Numeric -2.00%
Right Minimum Level Depth The minimum level depth between the existing surface and the bottom of the right overlay layer Numeric 0.300m (0.300 ft)
Right Slope Tolerance Tolerance for varying the right overlay slope Numeric, positive 0.50%
Left Lane Width The left lane width, determined by the offset of the outside edge of the left lane from the inside edge of left lane Numeric, negative -12.000m (-12.000 ft)
Right Lane Width The right lane width, determined by the offset of the outside edge of the right lane from the inside edge of right lane Numeric, positive 12.000m (12.000 ft)

Additional Input Parameter reference

Flapping within Tolerance:
Note: Because the slope difference between the existing ground crossfall and the ideal crossfall is within slope tolerance, the two sides of the road will output different corrected crossfalls relative to the existing ground (EG) surface crossfall for each side of the road. Each side of the road will have corrected crossfall set as close to the existing ground crossfall as possible.
Minimum Level Depth
Note: The minimum level depth represents the minimum depth of the levelling layer, measured between the existing ground high point and the bottom of the overlay layer.

Crown Offset

Note: The distance that the crown point for the subassembly is offset from the road centreline.

Output Parameters

Parameter Description Type
Left Corrected Crossfall The left corrected crossfall represents the adjusted crossfall for the left side of the road profile, which has been optimised to match, as closely as possible, the rehab subassembly parameters you specified. Percentage
Right Corrected Crossfall This is the adjusted crossfall for the right side of the road, which has been optimised to match, as closely as possible, the rehab subassembly parameters you specified. Percentage
Left Existing Ground Slope The crossfall (%) of the existing ground profile for the left lane, calculated from the inside edge of the left lane to the outside edge of the left lane. Percentage
Right Existing Ground Slope The crossfall (%) of the existing ground profile for the right side of the road, calculated from the inside edge of the right lane to the outside edge of the right lane. Percentage

Target Parameters

Parameter Description Required?
Target Surface The object defining the surface of the existing carriageway Yes
Crown Offset Target The object defining the offset of the crown point. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No
Left Lane Width Target The object defining the offset of the outside edge of left lane from the inside edge of the left lane. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No
Right Lane Width Target The object defining the offset of the outside edge of the right lane from the inside edge of the right lane. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No
Left Inside Edge of Existing Lane Offset Target The object defining the left inside sample point offset will be used to calculate the existing surface slope. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No
Left Outside Edge of Existing Lane Offset Target The object defining the left outside sample point offset will be used to calculate the existing surface slope. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No
Right Inside Edge of Existing Lane Offset Target The object defining the right inside sample point offset will be used to calculate the existing surface slope. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No
Right Outside Edge of Existing Lane Offset Target The object defining the right outside sample point offset will be used to calculate the existing surface slope. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines or survey figures. No

Behaviour

This subassembly assumes that no milling layer is added to the subassembly. Flapping, which controls the behaviour of the corrected crossfall that is output, is set within slope tolerance to meet the minimum level level. You can adjust level of the overlay layer if needed to meet the no mill and minimum level depth.
Note: It's not supported to adjusted the corrected crossfall by flapping after you have modified the level of the overlay layer. Procedurally, flapping should always be applied first, followed by vertical adjustment of the overlay if needed.
Inputs:
Inputs Value
Ideal Crossfall, Left -2.0%
Ideal Crossfall, Right -2.0%
Crown Offset 0.000' (0.00m)
Left Lane Width 12'' (3.6m)
Right Lane Width 12'' (3.6m)
Minimum Level Depth 0.000' (0.00m)
Slope Tolerance 0.50%
Overlay Slope Options User Defined with Flapping
Use Profile Options Minimum Level Depth
Calculations:
Left Side Input Value
High Point Crossfall, measured from Crown Point to High Point -1.2%
High Point Crossfall – Ideal Crossfall 0.8%
Slope Tolerance The Slope Difference between High Point Crossfall minus Ideal Crossfall result is 0.8%, which is greater than the Slope Tolerance of 0.50%
Corrected Crossfall The Corrected Crossfall will be adjusted to a value between -1.5% and -2.5% crossfall
Adjusted Level optional ("a")
Right Side Input Value
Existing Ground Crossfall -2.2%
Existing Ground Crossfall – Ideal Crossfall -0.2%
Tolerance Existing Ground Slope minus Ideal Crossfall is -0.2%, which is less than the Slope Tolerance of 0.5%
Corrected Crossfall The Corrected Crossfall will be adjusted to a value between -1.5% and -2.5% crossfall
Adjust level false ("0")
Final Input Value
Corrected Crossfall, Left -1.5%
Corrected Crossfall, Right -2.2%
Adjust level max(a,0) = adjusted level

Output

Output Value
Corrected Crossfall, Left -1.5%
Corrected Crossfall, Right -2.2%
Point, Link and Shape Codes
Point, Link or Shape Code Description
P1 Crown Crown point for top of overlay
P2, P3 EOV Overlay edges on finished gradient for left and right side of the road
P4 Crown_Overlay Crown point for bottom of overlay
P5, P6 EOV_Overlay Edges of bottom of overlay for left and right side of the road
P7, P8 EOV_Levelling Edges of bottom of level for left and right side of the road
L1, L2 Top, Pave Top of overlay for left and right side of the road
L3, L4, L5, L6 Overlay Overlay links (height and width) for left and right side of road
L7, L8 Level Level links (height) for left and right side of the road
S1 Overlay Area between the top and bottom of overlay
S2 Level Area between the top and bottom of level

Coding Diagram

Parent topic: Subassembly Reference (continued)