Key Construction Technology Of Diversion Tunnel In Mylonitic Fault Zone

With the use of water resources,constructions of hydropower stations further expland to romote and complex places during their rapid development.More and more complicated geological conditions make the construcion of projects encouter problems.The risk control of sudden water and mud inrush in mylonite fault zone relates to the success of hydropower stations.So,it is very important to study on how to go through the muddy mylonite fault.According to the construcon expriences of a hydropower staions,the thesis researches on the risk control of sudden water and mud and the tunnel consturction technology through the mylonite fault zone.Its research contents include detection method of mylonite fault in the complicated geological conditons,consolidation grouting technique and related constuction technology through mylonite fault zones.The research results as follows,1.The HSP advanced geology exporation technology was sucessfully applied in the detection of mylonite faults.Geology status of tunnel face was found out by this technoloyg,which solves many problems of complicated geological conditons and the tunnel located in the curve.2.The whole-section consolication grouting technique was applied in the sudden water and mud section,which solves the problem of difficult drilling.Certain reinforced structure formed at the range of slumping cavity by grouting improves the geological condition of surrounding rock effectively.Morover,Large pipe shed high-pressure grouting with working pressure of 15MPa improves futher before the excavation.3.The multi-steps excavation technique,first-bottom an then-roof arch lining technique and parallel multi-operation technique were effectively applied in the construction of diversion tunnel in mylonite fault zones.