sand compaction

例句：

1. 1. The engineer used a machine to compact the sand before building the foundation.
   工程师使用机器在建造地基之前压实沙子。
2. 2.The construction crew had to wait for the sand to reach the right compaction level before starting the excavation.
   施工队必须等待沙子达到正确的压实水平后才开始挖掘。
3. 3. The sand compaction process is crucial for ensuring the stability of the structure.
   沙压实过程对于确保结构的稳定性至关重要。