under-reinforced slab with slightly curved bottom

例句：

1. 1. The engineer designed the bridge to be under-reinforced to withstand heavy traffic.
   工程师设计这座桥为加固结构以承受重交通。
2. 2.The construction of the new highway involved the use of under-reinforced slabs for roadbeds.
   新高速公路的建设使用了下加强板作为路基材料。
3. 3. The under-reinforced slab was installed carefully to ensure stability during construction.
   下加强板被仔细安装以确保施工期间的稳定性。