名词 box beam:

1. a beam built up from boards; has a hollow rectangular cross section

boxn.盒子；箱子；包厢；专席；<口>电视机n.一拳；巴掌；耳光n.黄杨；黄杨木vt.把…装箱；使局限于狭小空间；挡住v.拳击；打耳光boxingn.拳击；盒式包装；制箱材料

1. The successful alternative was the cast-in-place segmental prestressed concrete box girder.
   最后采用的方案是分段现浇的预应力混凝土箱形梁。
2. It is provided with a telescopic bracket.The box beam at the external side of the telescopic part of the bracket is inserted into the square hole in the main beam.
   其中，拖架具有可伸缩功能，是通过可伸缩部分外侧的箱形梁插入货台主梁的方孔中，选择箱形梁上孔的位置来实现的。