今年3月6日,当军都山隧道出口工区平导八通上导坑掘进至正洞DK289+908处时,发生了罕见的地下泥石流,涌出碎石夹泥700多方,堵塞了八通的正洞工作面。4月29日,当正洞大断面掘进至DK289+916处时,地下泥石流从洞顶再次涌出,携带的碎石和泥沙在洞内沉积长度达70多米,体积 On March 6 this year, a rare underground debris flow occurred when the leading tunnel of Pingtutong pass, led by Pingdu Batong, the working area at the exit of the Dushan Tunnel in the work area, was flooded with more than 700 sides of crushed gravel and blocked the eight-way The positive hole face. On April 29, when the tunnel was drilled to DK289 + 916, the underground debris flow gushed out again from the top of the tunnel. The gravel and sediment carried in the cave lasted for more than 70 meters and the volume