A person stays and work at camp for 14 days, which is more than 100 km away, returns home for 7 days and again goes to same camp for 14 days, in such case will qasr be applicable at camp.
Bismillahi Ta’ala
Walaikum Assalam Warahmatullah
His home is whether his watn al-asli (permanent residence) or his watn al Iqama (temporary residence). He will perform full salah when he is at home.
When he leaves the boundaries of the city to go to his camp for less than 15 days, it will be considered his watn al sukna (transit residence), and he will be a musafir here and make his qasr (shortening).
In essence, wherever he will be categorized as a traveller, he must shorten, even if he goes there multiple time.
Wallahu A’lam
And Allah Ta’āla Knows Best
Mufti Faisal al-Mahmudi