Study and Application of Full-section Curtain Grouting After Disaster on Strongly Disturbed and Completely Decomposed Granite Formation
The completely decomposed granite formation features looseness, low strength, poor self-stability and high disintegration exposed to water. It can easily cause geological disasters such as water inrush and mud gush during tunnel construction and seducing secondary disasters especially in the strongly disturbed regions. The specific full-section curtain grouting is proposed to deal with the strongly disturbed and completely decomposed granite formation. The meticulous exploration which combined the geological exploration holes and transient electromagnetic is adopted to detect the hydrogeology conditions and the main water supply channel in the strongly disturbed region. Based on the control principles of grouting amount and pressure as well as the selecting principles of grouting material, we applies the multistage casing segregation technique to reinforce the strongly disturbed region. This achievement performed well in the treatment of water inrush and mud gush in the construction of Junchang tunnel in Guangxi province, and realized safe excavation of the right tunnel which is located in the strongly disturbed region. Also it can provide model significance to the similar constructions.