1. arch狭义上指的是拱门,它是一个二维的结构。例如,凯旋门的英文是triumphal arch,这表明arch通常用来描述“门”,一个二维的结构。英文释义为:a curved symmetrical structure spanning an opening and typically supporting the weight of a bridge, roof, or wall above it. • an arched structure forming a passageway or a ceremonial monument: a triumphal arch. • a shape resembling an arch or a thing with such a shape: the delicate arch of his eyebrows. • the inner side of the foot. 2. vault则表示三维的拱顶,是由多个arch在不同二维平面组成的三维结构。英文释义如下:1 a roof in the form of an arch or a series of arches, typical of churches and other large, formal buildings. • literary a thing resembling an arched roof, especially the sky: the vault of heaven. • Anatomy the arched roof of a cavity, especially that of the skull: the cranial vault. 3. 可以看出,arch和vault的关系类似于中国古建筑中的椽、檩、梁、枋与整个屋顶的关系。