Introduction - brief, fanfare-ish, and often in unison until a cadence at the end
1st Strain - the first melody, repeated immediately
2nd Strain - the second melody, builds slightly in intensity, repeated immediately
Trio - a section of repose (lower intensity), key change of +1 flat
Dogfight - intense and harmonically unstable section, to be resolved by the...
Grandioso - the climax, often repeats back to the trio/dogfight the first time
Of course, not every march follows this structure exactly, but this is the basic template. Let's use perhaps the most famous march ever composed as an example: "The Stars and Stripes Forever" by John Philip Sousa.
0:08-0:23 1st strain
0:23-0:38 1st strain, repeated
0:38-0:54 2nd strain
0:54-1:10 2nd strain, repeated
2:35-2:58 Dogfight, repeated
2:58-3:30 Grandioso, repeated
Now compare that with the formal design of "The Throne Room".
0:18-0:34 1st strain (Force theme) - F minor
0:34-0:48 1st strain repeat (add trombones) - F minor
0:48-0:56 Transition (based on the introduction, but a perfect fifth lower pitched)
0:56-1:12 Trio - D-flat major
1:12-1:29 Main theme, part b - D-flat major
1:29-1:46 Grandioso - D-flat major
"The Throne Room" uses a very simplified version of the march structure, but it is clearly related. Both share opening fanfares that start in unison, a repeated first strain, a transition to a trio with a key change of one added flat, and conclude with a grandioso.
That being said, of course, there are also obvious dissimilarities. "The Throne Room" omits the 2nd strain entirely, along with the dogfight. Instead, the 1st strain and trio are separated by a transition based on the music of the introduction; and the trio and grandioso are separated by the secondary part of main theme, the melody of which is then repeated as the grandioso.
That transition from 1st strain to trio (which in terms of structural function replaces the 2nd strain) is worth a close look.
Although much of "The Throne Room" follows traditional march tonal designs, one aspect that is somewhat unconventional is the fact that the first half is in minor. The majority of marches are in major the entire time (with the possible exception of the dog fight). Even so, there are some notable precedents, perhaps the most famous being Sousa's "The Gladiator March".