Thank you, James. This is good information I'll incorporate into my model.
A while ago, you posted about the heights of the bridge columns ( Link ).
"With the laser I measured the heights above curb of the second
column from the north (south side of sidewalk) on both the east
and west sides. The height for the east column is 24’ 5” while the
west column is 23’1”. The difference of 16” over 124’ gives an
average slope of -0.58 degrees in the westward direction."
One source said that not including the railing aspect of the Triple underpass, the [road into the] Underpass is 24 ft lower than the level of Houston street. I understand you measured the two columns from the top of the sidewalks but where to the top? That is, it would seem 24' 5" is not to the very top of the pillars but maybe to the bridge roadbed or the top of the railing?
My apology for the confusion. My goal was to measure bottom to top of the columns. This turned out to be more difficult than I anticipated. What I should’ve written is “I measured the heights above the
pedestal tops…” for the tunnel columns. Columns W1, W2 and W3 are numbered from the north increasing southward. The same for the east columns E1, E2 and E3. I began the measuring project with bridge column E3, which does extend down to the curb. The same with W3. I then began measurements of the tunnel columns W1 and W2. But for the tunnel columns I was not able to get direct (single) measurement from the top to curb, so decided on using the pedestal top as a base. My thinking then was to know the pedestal heights and add the two measurements. But the tunnel pedestals don’t reach the curb as they sit on blocks above the curb. It appears I did not make measurements of those blocks. Therefore, I can only provide column top to pedestal top lengths for tunnel columns. Here are data for each column. Precision or accuracy is not impressive.
Uh, would all of the pillar pedestal tops be at the same elevation?
Column Top to Pedestal Top
W1 21’4” (seems low, perhaps I measured the middle ‘step’ instead of the top)
W2 23’1”
E1 22’7”
E2 22’10”
Column Top to Curb
W3 30’0”, 28’6” (Elm traffic interfered with measurements, so no attempt to keep trying)
E3 27’3”, 27’7”