understructure
understructure — noun
1. the solid base built below ground level that holds up a building, bridge, or oth
the solid base built below ground level that holds up a building, bridge, or other large object and transfers its weight to the earth.
The contractor inspected the concrete understructure before building the new house.
the understructure of a building
An earthquake damaged the bridge's understructure, so engineers closed it for repairs.
Yuki noticed cracks in the understructure of the old warehouse during the safety check.
Without a solid understructure, the tower would slowly sink into the soft ground.
The building's steel understructure was designed to withstand strong winds and heavy snow.
- foundation
more common and can be both literal (concrete base) and figurative (origin/basis); 'understructure' is strictly literal and technical
- base
broader — the bottom part of any object; 'understructure' specifically refers to the supporting part below ground
- substructure
very close synonym, equally technical; 'substructure' is slightly more common in engineering writing
- superstructure
the part of a building above ground level that rests on the understructure
文法句型
the understructure of [noun]
用法筆記
Often used in technical or engineering contexts. The word emphasises the hidden, load-bearing part that is not visible once construction is complete.