底梁

mudsill
【机】 bedstone; bottom millstone

1.sillbeam  2.collar  3.groundsill  4.bottomgirder  5.maintimber  6.sill  7.basegirder  

底的英语翻译：

a copy kept as a record; base; bottom; end; fundus; the truth of a matter
【医】 base; basement; bases; basi-; basio-; basis; batho-; bathy-; fimdi
floor; fundus; pavimentum; solum

梁的英语翻译：

bridge; girder; roof beam
【机】 beam; girder