You're overestimating the tensile strength of the substructure you're building.

高估了基础分抗张强度。

Many ants also sing, but in most cases, this sound is transmitted through the substructure and not through the air.

很多蚂蚁也歌唱，不过多数情况下声音是通过底构造传播，而不是空气。

Dropped through the substructure by Mr. Blunt.

喷灯乙炔罐爆炸了。

I haven't been down to the substructure for weeks.

都好几周没去下面了。

We haven't even completed that substructure floor yet.

地下工程地面尚未完工。

Instead of beams that are loaded perpendicularly, arch bridges use a curved element to transfer the weight of the bridge to the substructure using almost entirely compressive forces.

拱桥不是垂直加载梁，而是使用弯曲元件， 几乎完全利用压缩力将桥梁重量转移到下结构。