concrete caisson sinking

例句：

1. 1. The construction crew was working on the concrete caisson sinking.
   施工队正在工作，处理混凝土沉箱下沉。
2. 2. The engineers were monitoring the progress of the concrete caisson sinking.
   工程师们正在监控混凝土沉箱下沉的进度。
3. 3. Due to the heavy load, the concrete caisson had already started sinking.
   由于重载，混凝土沉箱已经开始下沉了。