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This answer explains that this regular grid of concrete posts at Baikonur LC-1 Gagarin's Start is designed to reduce damage to the launch control bunker beneath it in the event of a catastrophic failure soon after launch:

Подземный бункер пуска - самое близкое к старту место. Над ним специальные бетонные столбики, так называемые волнорезы, чтобы ударная сила не повредила этот стратегический объект.

The underground bunker is the closest place to start. Above it are special concrete columns, so-called breakwaters, so that the impact force does not damage this strategic object.

How do these pillars help reduce damage to the bunker?

Clearly such a failure would result in devastating damage to the vehicle and any unprotected surrounding infrastructure.

Grid of pillars with Soyuz MS-09 launching in the background Image showing pillars with Soyuz MS-09 launching in background

Annotated map - pillars highlighted in red; background buildings in yellow. Annotated google maps image showing launchpad location

View of launch site showing the grid and the bunker entrance (blue) in the background Annotated google maps image showing launchpad location

Note - this question has changed to reflect the developments in the related question

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    $\begingroup$ Saving the vehicle is quite improbable but the pillars probably break the rocket quickly and stop or slow down many parts + it might reduce the shockwaves too? $\endgroup$ – jkavalik Jun 24 '18 at 12:08
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    $\begingroup$ Probably the idea is that by ensuring that the rocket breaks open, the propellants will disperse more and deflagrate less violently than if the rocket struck the ground intact. It's not about salvaging the rocket but mitigating damage to surroundings - launch equipment, blockhouses, etc. $\endgroup$ – Anthony X Jun 24 '18 at 14:09
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    $\begingroup$ I wonder if they are the remnants of a foundation of something that got destroyed. They are strangely non uniform in height. $\endgroup$ – Organic Marble Jun 24 '18 at 16:26
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    $\begingroup$ @Uwe agreed. I'm going to post a partial answer on the other question and probably scrap this one since the premise seems to be flawed. $\endgroup$ – Jack Jun 24 '18 at 16:34
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The citation you give is correct, albeit a bit misleading.

If a rocket fails so soon after launch that it strikes any of the structure on and around the launch pad, the result is in any case a huge explosion resulting in the complete loss of the vehicle. You can get an impression on how it looks like by the crash tests done by SpaceX in the past years using almost empty rocket booster stages (just with 100 times more fuel in the tanks). In such an event it is clear that all the buildings will suffer severe damage and a few concrete pillars will not make much of a difference.

Second, given the small size of the array, it is very unlikely that the rocket actually hits that. This makes it clear, that this wasn't built to save the rocket or the surroundings.

The only case the pillars make a difference is for the building underneath them - the control bunker of the launch site. In the unlikely case the rocket fails and significant parts of it drop on top of the bunker, there is the risk of damaging the concrete ceiling. The bunker seems to be quite robust, located 60 steps below ground - but on the other hand, 500 tons of of kerosene and LOX is nothing you want to have exploding just on the other side of the wall.

If the rocket hits the ground and explodes, a significant amount of energy and force is directed downwards because of all the additional material dropping down from above. This force can reduced substantially, if the rocket explodes while still airborne: The shockwave can extend in all directions, debris can spread and the "crushing" effect is not as strong as the lower parts of the rocket still can move further down.

This is exactly the purpose of the pillars: Breaking the rocket apart before it hits the ground and the top of the bunker.

Side fact: Tanks (the military things) use a similar technique called "reactive armor" - the tanks are covered by an explosive material that repels incoming projectiles and reduce the forces and destruction despite causing an additional explosion.

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    $\begingroup$ The link says that "a concrete-encased hill was built upon it" (it being the bunker) which does not look much like the flat plain in the picture. note: I'm pretty convinced that this answer is correct but that link doesn't really support it. $\endgroup$ – Organic Marble Jun 25 '18 at 18:20
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    $\begingroup$ Can anybody check the original text if "hill" is an accurate translation? $\endgroup$ – asdfex Jun 25 '18 at 18:31
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    $\begingroup$ Thanks! I've made some major changes to the question to reflect the developments in the related question. The conclusions you've made still stand and I've tried to phrase the question so you shouldn't have to make too many changes $\endgroup$ – Jack Jun 25 '18 at 18:34
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    $\begingroup$ @asdfex – the concrete-encased hill can be buried under standard ground which creates flat terrain above it $\endgroup$ – miroxlav Jun 26 '18 at 15:21

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