SOLVED. Adult Post Apocalyptic - Mixed group awakes in an enclave in island, no idea how they got there, MC is the only one with access to weapons. Read after 2010. Spoilers ahead. [s]

[David]

The group awakes each one in their bungalows, which are all in an enclosed enclave in an island. There is one exit, which leads to a beach. They can't walk far from the exit along the beach, there is a kind of sound frequency field a short distance each way which causes nausea and extreme discomfort if they stay long enough on it.

No one remembers how they got there. Some appear to have designated functions. One of the other characters appears to be the Mayor, since their bungalow's computer have administrative functions, while the MC has the only computer that can unlock a weapons vault. The rest of the group have different backgrounds that lets them do diverse tasks.

Part of the group somehow visit another area in the island, where they see a town/city almost completely destroyed, and I think they even discover someone alive, but sick/mutated/something.

Not sure when I read it, it was after 2010, can't be more precise.

SPOILERS



(view spoiler)[While on paper he should have been a good leader, the Mayor ends up trying to take over and control everyone, he even killed someone using the sound frequency field, by rendering them immobile inside the field until they died. If I remember correctly he ends up dying.

The MC discovers that there are multiple islands with the same setup as his, but most interactions Mayor/weapon specialist aren't remotely as bad like his.

Eventually they discover where are the ones that kidnapped them and created the enclaves, there was some kind of apocalypse and the enclaves were supposed to restart civilization or something like that. The weapon specialists destroy the bunker where the kidnappers are. (hide spoiler)]

[Mai]

From the summary and reviews this one seems to match your description!
Seed by Michael Edelson

[David]

Awesome, it really looks like it is the one.

Many thanks!