大直径盾构隧道双层衬砌横向抗震性能研究

Study on Transverse Seismic Performance of Double Lining of Large Diameter Shield Tunnel

为探明有无双层衬砌、双层衬砌不同施作方式(复合式、叠合式)对盾构隧道横向抗震性能的影响,以甬舟铁路金塘海底铁路隧道为工程依托,建立盾构隧道双层衬砌三维精细化模型的同时考虑了隧道材料与接触的非线性行为,采用隐式动力时程法进行了抗震性能研究。结果表明:(1)双层衬砌与管片的连接刚度越大,隧道变形越小;(2)复合式衬砌对隧道环向抗震性能提升有限,其变形、损伤及应力规律与单层衬砌基本一致;(3)叠合式衬砌能有效提升隧道抗震性能,充分利用材料力学特性,但需要重点关注隧道的损伤情况;(4)抗震设防等级要求较高的区段建议采用叠合式双层衬砌,防水、防火要求较高的特殊区段建议采用复合式双层衬砌。

In order to find out the influence of double lining and different construction methods(composite and superimposed) of double lining on the lateral seismic performance of shield tunnel, the three-dimensional refinement model of the double lining of shield tunnel is established based on the Jintang Subsea Railway Tunnel of NingboZhoushan Railway, and the nonlinear performance of tunnel materials and contact is considered. The seismic performance is studied by the implicit dynamic time history method. The results of the study show that:(1) the greater the stiffness of the connection between the double lining and the segment, the smaller the tunnel deformation.(2) The composite lining has limited improvement in the circumferential seismic performance of the tunnel, and its deformation, damage and stress patterns are basically consistent with those of the single lining.(3) The superimposed lining can effectively improve the seismic performance of the tunnel and make full use of the mechanical properties of the materials, but it is necessary to focus on the damage to the tunnel.(4) It is recommended to adopt superimposed double lining for sections with high requirements on seismic fortification grade, and composite double lining for special sections with high requirements on waterproofing and fire protection.