tunnelling (excavation)
type: Concept
preferred label: تونل‌سازی @fa
related: underground works

earthwork
type: Concept
preferred label: عملیات خاکی @fa
related: underground works

underground works
type: Concept
broader: civil engineering
preferred label: کار در زیر زمین @fa
related: tunnelling (excavation)
related: excavation
related: earthwork

excavation
type: Concept
preferred label: گودبرداری @fa
related: underground works

civil engineering
type: Concept
narrower: underground works
preferred label: مهندسی راه و ساختمان @fa