Technique of Advanced Reinforcement from Ground and Its Application in Tunnel Entrance Project

Construction principles and the technique of advanced reinforcement from ground for tunnel entrance projects are expounded based on surrounding rock characteristics of the tunnel entrances.The application areas and advantages of the technique are analyzed.The application and development trends about the technique are summarized.The technique of advanced grouting from ground was carried out at Dafengba tunnel in Grade 1 highway from Chuxiong to Dali in south-western China and the expected effects were achieved. After the surrounding rock is reinforced by advanced reinforced measurement from ground,its physical and mechanical properties will be improved,its self-stability will be promoted,and its loosen area and pressure on primary support will be reduced.Anchors and grouting tubes can play a role of hanging surrounding rock.Advanced grouting can reinforce and fill the land slide mass,preventing water from seeping into ground.