本工程建筑结构安全等级为二级，设计使用年限为50年。

The safety class of building structure of this project is II and the design working life is 50 years.

youdao

本工程建筑结构安全等级为二级，设计使用年限为50年。

The safety class of building structure of this project is II and the design working life is 50 years.

youdao