Question

when two ice cubes are pressed they join together explain the principal involved

Answer 1

The surface of the ice cube (in room temperature condition) unfreezes interacting with warm air. The same takes place between the contacting surfaces of two cubes. In the case of high pressure (if two ice cubes are pressed together) the freezing temperature increases. It will cause water freezing in the cleft between two cubes and the joining of ice cubes.