The deformation of normal roadbed is mainly controlled by compaction of soils,but that of the permafrost roadbed in Qinghai-Tibet Railway is mainly influenced and controlled by cryogenic course.

• 一般地区路基土体变形主要受土体压密过程控制,青藏铁路冻土路基变形则主要是受土体冷生过程影响和控制。