On the mainland,
工事 almost always means 'military fortifications' — trenches, pillboxes, bunkers — typically paired with verbs
修筑 (build),
构筑 (construct),
加固 (reinforce). In Taiwanese Mandarin and through Japanese-influenced usage,
工事 can also mean general 'construction works' or 'building site' (matching Japanese
工事 kōji).
