立体交叉
1. 立体交叉：力矩 moment of force | 立体交叉 grade separation | 连接 connection
2. 简单立体交叉：grade of side slope 边坡坡度 | grade separation 简单立体交叉 | guard rail 立体交叉
3. 等级区分：等级类别 grade category | 等级区分 grade separation | 等级应力;应力分类;应力分等 grade stress
4. 立体交：平面交* level crossing | 立体交* grade separation | 道囗 grade crossing; level crossing