Numerical Analysis Of Leading Ductile Injecting Pre-reinforcement In The Tunnel

Many tunnels especially their entrance are weak and of poor self-stability，inorder to ensure tunnel’s safety and economical efficiency during its construction，pre-support the weak rock is needed.As a pre-support solution leading ductile injectingmethod has gradually become a new technology to solve the problem of tunnel undercomplicated geological conditions.It has played an important role in tunnel constructionin bad geological conditions such as shallow burying，weak broken stratum，etc.so that,leading ductile injecting, especially applied in small cavern pre-support and tunnelcollapse treatment.As a result of its economy, flexibility and good reinforcement, thiskind of reinforcement has become more widely-used in engineering practice.It’snecessary to research leading ductile injecting method.First through the literature research，on the basis of the research results of theformer，Discusses the leading ductile injecting method， the major work completed inthis paper：1. Starting from the mechanism of leading ductile injecting method.Mainlyanalysis of grouting mechanism and small pipe mechanism，and discusses the mainparameters of the leading ductile injecting.2. Completed the model of leading ductile injecting，analysis the stress anddisplacement of tunnel surrounding rock.Completed the model of small pipe，derive theformula of deflection，bending moment and the corner of the pipe.3. Through the numerical analysis by making use of FLAC3D software，obtained the reinforcement effect of leading ductile injecting method by comparingpre-reinforcement，and analysis the reinforcement effect of different C/D.4. Discusses the reinforcement effect of various factors in leading ductile injectingthrough numerical analysis，mainly analysis thickness of grouting，the diameter and gapof pipes.Studying the influence of reinforce scope on tunnel failure mechanism.