backfilling
n. [建]回填
v. [建]回填（backfill 的 ing 形式）
例句
The gravel is one of the most common materials for abutment backfilling.
砂砾是台背回填工程常用的回填材料之一。
Not backfilling silt, corruption and graft, permafrost soil organic matter.
不得回填淤泥、腐植土、冻土及有机物质。
Through the experiments, the mixture ratio of cemented crushed stone backfilling materials was optimized.
通过试验，优化了碎石胶结充填料配比。
