rail something off
phrasal verb with rail verb [ I + prep ] formal uk/reɪl/ us/reɪl/
（尤指用栏杆）把…围起，把…圈住，把…隔开
to close something, especially using railings
Part of the playing field had been railed off for use as a car park. 运动场的一部分被栏杆隔开，用作停车场。