Terms for subject Rail transport containing bed of

English	Chinese
bottom layer of subgrade bed	基床底层
bottom of ballast bed	砟底
shoulder of ballast bed	道床砟肩
soft spots of road bed	路基松软
sound-absorbing slab of track bed	道床吸声板
surface layer of subgrade bed	基床表层
toe of ballast bed	砟脚
top of ballast bed	砟顶