Management Technology for Water and Mud Inrush in Deeply Buried Tunnel Crossing High-pressure Water-rich Faults
Water and mud inrush in tunnels crossing high-pressure water-rich faults is highly destructive with low groutability.To address this challenge,we examined the geological characteristics,disaster processes,and causes associated with water and mud inrush in the Xianglushan Tunnel of Central Yunnan Water Diversion Project as a case study.We propose a combined management strategy consisting of drilling,grouting,pressure relief,and sup-port all in advance.To tackle the high content of fine powder in the surrounding rock of the tunnel's lower half sec-tion,which impedes the diffusion of grouting slurry,we introduce a replacement grouting reinforcement technique.This technique involves dividing the grouting holes into top holes and back(or horizontal)holes.Grout is injected through the top holes,while pressure is released through the back or horizontal holes to flush out rock powder.This approach facilitates the removal of rock powder and improves slurry diffusion.Our method successfully resolves the water and mud inrush disaster in DLI3+681.5 section of Xianglushan Tunnel.The research findings offer valuable insights for managing water and mud inrush disasters in tunnels with similar geological conditions.