1) permanent way

永久性铁路
2) perpetual pavement

永久性路面
1.
Through analysis design idea,characteristics of structure,function of pavement layers and nature of materials of semi-rigid pavement and perpetual pavement and combining with Chinese reality,the application conditions for perpetual pavement and semi-rigid pavement are put forward.
通过分析半刚性基层路面和永久性路面的设计理念、结构特点、结构层功能和材料性质,并考虑中国国情,可总结出半刚性基层路面和永久性路面两种路面结构型式的适用条件:半刚性基层