understructure
🇬🇧/ˈʌndəˌstrʌktʃə/ 🇺🇸/ˈʌndərˌstrʌktʃər/lowest support of a structure; "it was built on a base of solid rock" "he stood at the foot of the tower"
noun [抽象名词] 基础；下层结构
Analysis of the understructure of the silo with an intermediate post 带内柱筒下层结构的分析
