Study On Deformation Mechanism Of Crossing Ground Fissure Metro Tunnel And Its Control Technology

The deformation mechanism of crossing ground fissure metro tunnel and its controltechnology has impotant engineering application value.On the background of xi’anmetrotransversing line1chaoyang gate～kangfu road section,in this paper, mechanicalcharacteristics of crossing ground fissure metro tunnel are completed. The major works of thispaper are as follows:(1) The mechanical characteristics of tunnel lining structure which in the up plate ofground fissure,the internal force of lining and rock pressure were analysised, the resultsindicated that the moment of dome and tensile area of haunch increased because of verticalpressure of tunnel increased. Suggestions on reasonable thickness of secondary lining.(2) The deformation mechanism of shallow subway tunnel construction which crossingground fissure with45°and the effects of deformation of tunnel on different vertiealdisplacement. were revealed by finite element numerical simulation. It was shown thattunnel Lining Structure not only appeared longitudinal difference settlement and bendingdeformation but also appeared transverse bending deformation and torsion deformation, andthe deformation amount increased with the increasing of vertieal displacement(3) The damage mode of tnnnel with active ground fissure was studied. It wasconcluded that hazards of tunnel included track deformation、waterproofing failure and so onwhich leaded to the deformation of tunnel structure. Then proposed the controlmeasures,generally divided into structure control measures and ground consolidationmeasures.The control measures of this paper are reasonable and feasible by in-situmonitoring.