南岭隧道全长6058m,是衡广复线的重点工程。当1984年6月11日出口下导坑掘进至DK1935+745时,遇溶洞发生突泥突水,涌出稀泥浆3549m~3,淹没下导175m,推倒排架32排。在处理过程中又陆续发生地陷和突泥多次,其规模之巨大与频繁程度为世界隧道修建史上所少见。兹将该处三次突泥情况列表如下: Nanling tunnel length of 6058m, is the key project of the Heng Guang double line. When on June 11, 1984, when exporting to the next guide pit to DK1935 + 745, a sudden muddy water burst occurred in the karst cave, pouring a thin mud 3549m ~ 3, submerging the lower guide 175m, and pushing down the 32 rows of shelves. Subsequent to the process of subsidence and mud suddenly occurred again and again many of its size and frequency of the world’s tunnel construction history is rare. Here’s a list of the three mud conditions listed below: