MXRENEW Function
Control
This panel leads you through the MXRENEW part of
the design process. It makes options available as
prerequisite options are completed. Any available options may be amended or revised at
any time.
Define Surfaces Wizard
This option is used to specify the design and
ground models, as well as identify the edges of proposed and existing
pavements.
The existing edges must be continuous and extend beyond the start and end of
the design. They can run in either direction. However, care should
be taken to ensure that they do not double back on themselves.
After supplying all the required surface
information, the Existing Pavement Relative to Alignment viewer is
displayed. This allows one to step or run through views of existing
sections relative to the proposed alignment. The white line represents
the existing pavement surface described in the wizard.
This
option is required prior to Parametric Fitting.
Overlay Depths
This option is used to specify the nominal
overlay depths, which can vary along a scheme. These overlay depths can be used to
form a new profile, or act as a guideline for a new vertical design.
This
option is not required prior to Parametric Fitting.
Cross Slope Tolerances
The designed cross slopes can be allowed to
vary. MXRENEW uses a technique called Flapping to optimize the
design cross slope with respect to the existing conditions. The amount
of potential Flapping can be controlled for positive and negative adjustments,
as well as for left and right lanes.
MXRENEW automatically optimizes the cross slope
from the values given in the Cross Slope Tolerances panel when Parametric
Fitting is selected.
Warning: There is no method to control
the cross slope rate of change. Apply Flapping with discretion.
This
option is not required prior to Parametric Fitting.
Parametric Fitting
This option lets you optimize the design road
template in
both profile and cross section. The profile can be adjusted to either follow the
existing ground elevations, the nominal overlay depths, an interactive design,
or any combination of all three of these methods. The
profile elevation at any section can also be adjusted. Any amendment to the
profile can also be undone within the same Parametric Fitting session.
The overlay depths you
specify are used to ensure that the design surface achieves this minimum
requirement, regardless of where on each section this may be.
The Parametric Fitting panel has a Cross
Section Window, a Profile Window, a Menu area and a Control area.
Both windows update immediately when changes are made. Familiarity with
this panel's
operation is very important, and time spent understanding how the information
is presented, and how it can be changed is essential.
The Design Menu
Original Profile to apply the Original
profile elevations to the proposed design for any station range specified.
Fitted Profile to apply the Fitted
profile elevations to the proposed design for any station range specified. The major
benefit of the Fitted profile is the guarantee that the overlay depth is
achieved over the whole roadway, not just above the center line.
Design a Profile to modify the Current
profile or redesign a new one. Of the three choices to design a
profile, the New Hampshire vertical design standard is the PI method.
The PI method uses Quick Vertical
Alignment as the design tool. The display includes the Existing
Ground profile and the Fitted profile.
The Profile Window
The vertical exaggeration for the Profile Window
may be
controlled with the selector at the top. Zoom control buttons are also located on the top.
When the cursor is moved in the Profile
Window, the Cross Section Window changes to show the details of
the current cursor position, which is enhanced by a vertical green line.
The bottom of the Profile
Window displays the elevation of several profiles, with text colors that correspond
to the profile colors. A check box for each profile allows one to
toggle the display of each profile. The cyan solid line shows the Current
profile, and a yellow dashed line (the 'Fitted' profile) shows the effect of
the overlay
depths entered earlier. The green dashed line
shows the Existing profile. The difference between the
Fitted and Existing
profiles may not be the same value as the overlay depth specified. This
is because the Fitted profile elevation has been calculated from the
"worst case" on each cross section. This ensures that the
overlay depth can be achieved across the entire section. Any revisions
to the Current profile will leave a red dashed line showing the Original
profile. A white dashed line shows the Design profile, but not until the Design a Profile option has been used.
With the cursor in the Profile Window,
"right click" to
lock the profile in the current position. The Station Selector
shows the current station. Use the arrow buttons to increase
or decrease the current station. With the cursor again in the Profile Window,
"right click" to
unlock the profile.
The Cross Section Window
The Cross Section Window displays the design
section in cyan, the existing ground sections in green with the existing road
shown in white.
The yellow dot shows the location of the Fitted profile. A green dot shows the location of the
Existing profile. The red dot shows the position
of the Original profile. The colors used in the Cross Section Window
correspond to those used in the Profile Window.
The elevation differences at the center line and the
proposed roadway edges are displayed along the top of the Cross Section Window, the background
for these values turn from green to red when the nominal overlay is impacted. The
specified overlay depth is displayed on the bottom left of the Cross Section Window. The vertical exaggeration for the
Cross Section Window may be
controlled with the selector at the top.
The Cross Section Window
shows the Current profile elevation at the bottom. The two
spinners next to the profile elevation allow edits to the center line
elevation for that station,
the left spinner changes the elevation in one millimeter (0.001
feet) increments, and the right spinner changes the elevation in one
centimeter (0.01 feet) increments. The design cross slopes and offsets
are maintained for each section, therefore the proposed roadway edges will
also rise and fall with the center line elevation.
The Pavement Depth found on the bottom
of the Parametric Fitting panel adds a magenta line to the Cross
Section Window showing the pavement depth relative to the other cross
section strings. This is simply a viewing tool for checking how the design relates
to the existing road.
Finishing MXRENEW
In order to apply adjustments made in Parametric
Fitting, select OK at the bottom of the panel. A message box
asks you to confirm the creation of a MXRENEW design model. The new
model is given the name of the Project followed by MXR DESIGN,
and you are returned to the Function Control panel. Select Finish
from the Function Control panel to exit MXRENEW.
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