All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
It is permissible to bury a dead man in a graveyard allocated to women or in a grave where dead women are buried, or vice versa. Muslims' graveyards, from the beginning of Islam until now, contain graves of both men and women, without any objection, on the part of scholars.
If the questioner means burying dead men and women in the same grave at the same time, then this is permissible in case of necessity. It was narrated on the authority of Waathilah ibn Al-’Asqa‘ that the Prophet, sallallaahu ‘alayhi wa sallam, buried a dead man with a dead woman together in one grave, placing the man in the front and the woman behind him. [Abdur-Razzaaq]
With regard to whether the torment or delight of all who are buried in the grave will stop until they are separated, then this is baseless and false.
Allaah Knows best.