中文摘要：

台阶式是山区地形普遍采用的一种场地布置方式,它的一个特点是场地内存在变坡线,如直接用三棱柱法计算场地土方,会遇到三棱柱横跨变坡线而导致土方漏算、多算的问题。本文首先提出了棱柱三角形对的概念,在此概念基础上给出了计算场地零线、土方的方法,之后分析了台阶式场地变坡线的问题,提出了加约束边并对三角形网重构的解决方法。通过具体实例的验证,提出的方法可行并提高了土方计算的准确性。

英文摘要：

Stage style is popular one at mountain area. For earthwork calculation at slope area with stages, the problem is that certain triangles in the mesh crosses lines of slope-change and introduces calculation errors. Firstly, the concept of prism triangle pair is presented. Based on it, the method of calculating zero-line and earthwork is given. Then, the slope-change lines are used as edges for inserting new triangles into the mesh so as to eliminate question triangles. Finally, an example is given to validate the method, and the result shows that it can improve accuracy of earthwork calculation.