【摘要】 积木法是一种以线元为核心的曲线型设计方法．立交线形设计时，已知前一单元终点的信息如坐标、切向或法向方位角、曲率半径等，在选定下一单元形式和其他有关信息的条件下，进行下一单元的设计．自始至终，一个单元接一个单元，如搭积木一样，完成整条匝道或主线的平面线形设计．本文主要介绍积木法的原理、方法与步骤．更多还原

【Abstract】 The building-block method is one of the curve-type designing methods based on alignment unit.When designing in-terchange ailgnment one canlay out the next unit if the information of the pre-existing unit such as coordinates,tangentazimuth and curature radius are known,and if the type and other ralcotional information of the next unit are elected.One can therefore complete the horizontal alignment design of a entire-ramp or a through line.This paper discusses theprinciple and the procedures of the method.更多还原