2009年6月22日21时40分,汉丹铁路线上全国首例13孔、长达200米的铁路立交门式墩施工提前3天“收官”。这是中铁七局集团四公司第一次承建的一项技术复杂、时间紧迫、安全压力巨大的攻坚工程。13孔门 At 22:40 on June 22, 2009, the first 13-hole, up to 200-meter-long railway interchange across the country on the Han-Dan Railway line was constructed three days in advance. This is the first time that the four companies of the Seventh Group of China Railway Construction Corporation undertook a crucial project with complicated technology, time constraints and huge security pressure. 13 hole door