摘要
本文从几何学的角度对互通式立交平交口的坡度合成问题进行了理论计算，为平交口的设计提供了一种方法， 解决了以往平交口设计中误差大、数据混乱问题，
This paper calculats the grade crossing slope in interchange from geometry.A method for grade crossing design that solve the problem of error and data confusion is presented. And the method is useful to drainage of grade crossing.
