Converting Connecticut DOT PDF Sections

In this video we show the conversion of a set of sections created by Connecticut DOT / Connecticut Engineers. The sections are provided in PDF format and have the following issues

  1. There is no text in the sections only Polyline versions of the text rendering the text useless
  2. The data is not layered - so you have to work around the layering

Otherwise the data can be processed as follows

  1. Take the datum grid line and the 0 offset grid line for each cross section and relayer it to e.g. CADXS - Grid Lines layer
  2. Elevate the datum grid lines to their elevation text value i.e. the elevation says 165 so make the line elevation 165 - this is then used as an alternative to the elevation text which is not present in this file
  3. Elevate the 0 offset grid lines to elevation 0 for the same reason as (2) above
  4. Add the station labels to all sections using the Increment Text command - again these need to be created because there is no text to work with that gives the Station values
  5. Find the data that you need for the Existing Terrain and relayer it to e.g. CADXS-Existing layer
  6. Find the data that you need for the Design surface model and relayer it to e.g. CADXS - Finished Grade layer
  7. Because there are no Grid Labels you are going to need a blank / empty layer that you can select for the Grid Labels to ensure that no random text on a layer could be used to try and compute scale and offsets / elevations - the elevation will be derived from (2) and the offset will be derived from (3) in combination with the entered horizontal and vertical scale determined in (8) below
  8. Determine the scale from the PDF grid lines for horizontal and vertical axes. Remember you are working in Sheet view and Sheet View works in inches. If you measure the distance between offset grid lines -70 and +70 (140’) and it says the distance is 28" then 28"=140’ or 28"=1680" therefore 1"=60" therefore you have a scaleup of 60 when you run the conversion process to 3D lines. Do the same for the elevation grids to see if you have any vertical exaggeration to take care of.

In this example the user was not interested in quantities, they were trying to establish clearing limits for a project they had won and found that the plan view limit lines were not matching the cross section limit lines in all places - they wanted to convert the sections to help establish / clarify the clearing limits for the project start. Because of these requirements it was not necessary to separate out the Finished Grade and Subgrade data, only to sort it out enough to make it usable for this purpose.

The biggest time sumps with this type of data are

  1. Separating the Datum and offset 0 grid lines on each sheet (172 sheets)
  2. Elevating the Datum and offset 0 grid lines - mainly the datum lines
  3. Adding the Station labels to all cross sections

Other than that this conversion is easy - however those 3 steps above take time to resolve in the absence of real text.

Video shows you how