【摘要】 相较于常规直径盾构隧道来说，超大直径盾构隧道施工对地层的扰动更大，易诱发既有运营隧道产生过大变形，因此需要采取一定的工程措施来减小对既有隧道的影响。以北京市东六环超大直径盾构隧道下穿既有6号线盾构隧道为工程依托，建立了三维有限元数值模型，并通过现场实测地表变形验证了模型的可靠性，进一步研究了新建盾构隧道穿越过程中既有隧道的力学响应特性以及中盾类克泥效注浆与径向深孔注浆微变形控制措施对既有隧道变形的控制效果。结果表明：在新建盾构隧道西线和东线先后施工影响下，既有隧道产生的最大沉降值分别为1.96 mm和2.68 mm，分别发生于西线隧道正上方和新建双线盾构隧道中心处；随着盾壳收缩率的增大（类克泥效注浆措施发挥作用逐渐减弱），既有隧道的最大竖向变形呈现出逐渐增大的趋势；相较于无径向深孔注浆工况，径向深孔注浆措施分别减小了西线和东线隧道施工过程中既有隧道0.18 mm和0.32 mm的沉降值，证明了径向深孔注浆对既有隧道的变形起到了抑制作用；相较于径向深孔注浆措施，类克泥效注浆措施对既有隧道变形的控制效果更好。研究成果可为类似超大直径盾构隧道的设计和施工提供理论依据与数据支撑。更多还原

【Abstract】 Compared with conventional diame ter shield tunn els, the construction of ultra diameter shield tunnels causes greater disturbance to the strata, which can easily cause excessive deformation of existing tunnels. Therefore,some engineering measures must be taken to reduce the impact on existing tunnels. Based on the project of ultra diameter shield tunnel crossing the existing shield tunnel of Line 6 in Beijing East Sixth Ring Road, a 3D finite element numerical model was established. The reliability of the model was verified by the measured surface deformation on-site. Further research was conducted on the mechanical response of the existing tunnels during the tunneling process of newly constructed shield tunnels, as well as the effect of micro deformation control measures such as middle shield grouting and radial deep hole grouting on the deformation of existing tunnels. The results show that the maximum settlement value generated by the existing tunnel is 1.96 mm and 2.68 mm, respectively, occurring directly above the west line tunnel and at the center of the new double line tunnel, under the influence of the sequential construction of the west and east line of new shield tunnel; As the shield contraction rate increases(the effect of cement grouting measures gradually weakens), the maximum vertical deformation of the existing tunnel shows gradually increasing trend; The radial deep hole grouting measure reduced the settlement value of 0.18 mm and 0.32 mm in the existing tunnels than the condition without radial deep hole grouting during the construction of the west and east line, respectively, proving that radial deep hole grouting has a restraining effect on the deformation of existing tunnels. The middle shield grouting measure has a better control effect on the deformation of existing tunnels than the measures of radial deep hole grouting. The research results can provide theoretical basis and data support for the design and construction of similar ultra large diameter shield tunnels.更多还原