Unless there is a bridge, tunnel, or other special structure, this roadbed is constructed of in-situ soils or on earth embankments.
只要没有桥、隧道或其他特殊建筑，路基就可以建在土堤上。
2
Based on model comparison between the semi-infinite earth and the circular tunnel with peripheral infinite earth, the conception of long and large tunnelin the electrical meaning is put forward.
在比较半无限平面大地模型和四周无限大地圆形隧道模型基础上，提出电气上的长大隧道概念。
3
The earth pressure balance shield is the main method of constructing the shield tunnelin the soft soil area.