i think you might be right about the tunnel between the main storage room and the runway. but there are solutions for that, since the base is not finished yet it could just be that another taxiway to the runway will be built. Where i definitely disagree is with your predictions about repairs. in wartime there is definitely no investigation that will take a month. Unless the entire structure has completely collapsed, the debris would be removed in a matter of hours with multiple bulldozers.Unfortunately, such a small tunnel would be destroyed to shreds by just one GBU-28.
The mountain connected to the runway is only 30 meters high at its peak and has a gentle slope. Even if the missiles were to land with only a few meters error, it is hard to imagine the time it would take to completely collapse the entrance and restore it.
Even a much smaller scale tunnel collapse in Japan took one month for investigation and one month for restoration work.
The reality is that once a tunnel is seriously damaged, there is a possibility that it will collapse again if work is done too easily, so even the investigation takes a very long time.
If just one missile can disable dozens of fighter jets and nullify the large amount of money invested in their construction.
What an easy target that would be for the U.S. and Israel to thrill at!
However, I believe that this covered interim structure serves a purpose, certainly as a passive defense against cruise missile and/or drone attacks. (just a guess) after all, they irgc thought of something and could have removed this structure to make the taxiway barrier free.
Regarding bombs and tunnel intrusion:
From an engineer's perspective, I would like to make the following comment: If a bunker buster enters the tunnel and explodes, the pressure from the explosion will first try to take the path of least resistance. In other words, the explosion wave will mainly press out along the tunnel or, in the case of the outer roofed intermediate structure on the taxiway, at the openings. The explosion will most likely not cause the structure to collapse. This can also be observed in various tests conducted with bunker busters and hardened aircraft hangars. see video:
to completely destroy a bunker in a room, you would have to hit a very specific enclosed space in an underground facility so that the explosion wave is forcibly released into the surrounding material. The tunnel itself is designed to transmit, attenuate or stop pressure waves. Furthermore, the rooms themselves are (here maybe not completely) but usually the best protected point of the whole structure.
In this example, we see the attenuation of the pressure wave over the length of the room (attention: closed room).
in order to bring the main tunnel to a complete collapse, the entire load-bearing structures would have to be destroyed, and this is only possible at certain points, if at all. The tunnel is actually built with hard concrete and this super hard concrete is surrounded by softer earth material. Even if you explode a bunker buster bomb in the earth, the explosion would again take the path of least resistance and be reflected back into the softer earth layer at the harder tunnel shell.
If the bunker buster bomb is really set so precisely that it explodes exactly in the concrete tunnel core, then the explosion would still not want to escape sideways but at the point with the smallest wall thickness. this means that the explosion will damage the concrete, but the pressure wave will try to escape at the point with the smallest wall thickness.
To collapse the entire load-bearing structure with a bunker buster is therefore not very easy.