The Technical Research Of Safely And Rapidly Construction On Large Section Tunnel Of Horizontal Gently Inclined Rock

On the background of Longevity Hill tunnel of Yuli Railway, aiming at safety accidents of surrounding rock chipping and collapse easily arisen by constructing large-span tunnel in the horizontal gently inclined rock, the context analyzes deeply the destruction mechanism of tunnel surrounding rock deformation in the horizontal gently inclined rock.Through building continuous medium model by FLAC3 D, calculating and analyzing the stability of surrounding rock of Wanshoushan tunnel, and calculating and analyzing again the stability of surrounding rock of double-track railway tunnel under the discontinuous medium by utilizing discrete element calculation software 3DEC, the concept of “be afraid of soft not scattered” of gently inclined rock is put forward.The destruction process of tunnel surrounding rock is reflected concisely and visually by means of site model test, which is contrasted with the results from numerical simulation and model test; the deformation regularity, destruction features and scope of influence of horizontal gently inclined rock are summarized.Aiming at the destruction features of horizontal gently inclined rock, the context studies and puts forward the supporting type combining radial direction anchor stock with advanced anchor stock, sets up and promotes the philosophy of “light support” of horizontal gently inclined rock, that is on the basis of steel fabric pouring concrete supporting, to reinforce the surrounding rock by utilizing anchor stock, install W-steel tape and form the combined supporting type, which is combing the scattered anchor stocks into an integral bearing structure, giving play to functions of shearing resistance natures and anchor rock composite beam of steel belt, thereby prevent effectively jointing continuous cutting arc surrounding rocks, enhance the self-supporting ability of surrounding rock, and strengthen self-stabilization of surrounding rock, forming finally the new-type tunnel supporting system with rigidity and flexibility. The new-type tunnel supporting system has strong reference and guidance for similar stratum construction with wide prospect in popularization and application.