rockfill dam with vertical clay core

例句：

1. 1. The rockfill dam is a crucial part of the flood control system.
   土石坝是防洪系统的重要组成部分。
2. 2. The engineers carefully planned the construction of the rockfill dam to ensure its stability.
   工程师们仔细规划了土石坝的建设，以确保其稳定性。
3. 3. Due to the high water levels, the rockfill dam was forced to be expanded.
   由于水位过高，土石坝被迫扩大。