construction waste soil; surplus excavation soil
Refers to soil generated from construction or excavation that is not reused on-site and must be disposed of or managed.
Disposing of construction waste soil is expensive.
The surplus excavation soil from this site was reused in another project.
残土 is a broader term for leftover soil from any earthwork, while 建設残土 specifically refers to soil from construction activities.
Compound of 建設 (construction) and 残土 (residual soil).