Analyzed The Stability Of Surrounding Rock And Simulated The Construction For Xi-Zhuang Tunnel Of Tai Jia Highway

The double multi-arch tunnel which is a new large span tunnel is presented with the rapiddevelopment of high way building in our country. Its route is fluent and impropriating the areais small and the ratio of utilizing space is high. It is easy to connect the out road with avoidingthe embankment in the tunnel exit or the bridge framing. It has the advantages of adapting thecondition and protecting the environment and engineering quantitatively. The removingbuilding is reduced and the engineering charge is reduced by using the double multi-archtunnel during the construction in city. The double multi-arch tunnel is designed under thecondition buried shallow tunnel with the moderate to short length. The surrounding rocks willhappen when the load is removed and returned and the stress will be redistributed duringtunnel digging. The surrounding rock will lose the stability when its strength is too low toadapt the stress redistribution. It will bring out the deformation and failure of surroundingrock if we do not reinforce timely or cannot assure the quality of reinforcement, which willtake some disadvantages for the construction and operation of the underground building.Because the geological condition is poor during the construction of double multi-arch tunnel,the hidden trouble of the surrounding rock instability and desformation exists. So it is aimportant content with closely relating to the construction of tunnel and operation in the highway that analyzing the stability of surrounding rock.Base on the construction double multi-arch tunnel of the Nanshi-Mengyang high way,the tunnel construction is simulated by analyzing the stability of the surrounding rock andprotecting the stability of the surrounding rock and supervising the construction. The mostweakness site of the surrounding rock stress strength is pointed out during the process of thetunnel construction. The local instability and breakage of surrounding rock is forecasted andprevented which can assure that the stability of surrounding rock can arrive at the requests. The stability of surrounding rock is analyzed systemically by the methods of combining thebody analysis with the local analysis.At first, base on the geological engineering factors of influencing the stability ofsurrounding rock, the mechanism of deformation and failure for the surrounding rock isanalyzed and discussed. Aim at the geological characteristics of the elastic-plastic propertiesof the structure face and the shallow interlayer, the strength-stress controlling mechanism isthought as the main mechanism of deformation and failure. The destroy manner of spreadingcollapse and fracture flaking is the main manner for the surrounding rock..Secondly base on the engineering geological condition of the double multi-arch tunnel inthe Xi Zhuang, the factors of the initial geo-stress and the underground water and the weakstructure surface is modified properly by utilizing the national code"Classification Standardfor Engineering rock". The classification of surrounding rock of double multi-arch tunnel inXi Zhuang is analyzed exploringly. The quality index (BQ) of surrounding rock is confirmedwhich can use to reference for the classification of surrounding rock. The classification of thesurrounding rock is theâ…£type by analyzed all kinds of classifications of surrounding rock.The tunnel construction is simulated by the program of ANSYS after building theelastic-plastic model. The stress states during the construction is simulated. The rules of thestress and distortion in the surrounding rock and structure is analyzed detailedly for thedouble multi-arch tunnel building in the three hole.The elastic space model is built at last. The space effect during the dig of doublemulti-arch tunnel and the interactional of the right hole and left hole is simulated, at the sametime the distortion of dividing-wall is simulated too. It can give some advances for the designand the construction of double multi-arch tunnel in the soft rock.