backfill density

例句：

1. 1.The construction of the new road backfill density is crucial for its success.
   新路的建设回填密度对它的成败至关重要。
2. 2. The engineer carefully calculated the backfill density to ensure stability.
   工程师仔细计算了回填密度以确保稳定性。
3. 3. The backfill density affects the overall strength and durability of the structure.
   回填密度影响结构的整体强度和耐久性。