Question

why the buildings in japan are not falling while earthquake?

Answer 1

Many cities vulnerable to the earthquake in the developed world has strict building codes for buildings ,tunnels, stadiums etc. to prevent earthquake damage and it is also earthquake resistance building

Answer 2

Damage to building was slight as a result of Japan's stringent building regulations that ensure that skyscrapers sway in during a quake, but don't collapse. ... Another method allows the base of a building to move semi-independently to its superstructure, reducing the shaking caused by a quake.