That's partly because bending forces introduce tension in structural members.

部分原因是弯曲力在结构构件中引入张力。

It's a common way to get structural steel members in whatever shape the design requires.

这是获得设计所需的任何形状的结构钢构件的常见方法。

One of the biggest questions everyone is asking, and rightly so given the severity of the situation, is " how long has this structural member been cracked? " National bridge standards require inspections for highway bridges every two years.

考虑到情况的严重性，每个人都在问的最大问题之一是“这个结构构件破裂了多久了？ ” 国家桥梁标准要求公路桥梁每两年检查一次。