为探究采用反拉式顶管法施工盾构隧道联络通道过程中主隧道的力学响应机制，依托北京地铁某盾构区间，建立模拟联络通道施工过程的有限元模型，通过与现场监测数据对比验证模型的准确性。继而研究联络通道施工对主隧道管片间错台位移、特殊管片应力及变形、螺栓受力的影响，并分析反力模式对主隧道管片力学特性的影响。结果表明： 1）始发管片破除对主隧道力学性能影响较大，随着联络通道进一步开挖，主隧道受力和变形缓慢增大。2）管片间最大错台位移为1.17 mm，发生在特殊管片与普通管片接缝底部。特殊管片最大拉应力为18.6 MPa，出现在开口的顶、底部；最大压应力为27.0 MPa，出现在开口的腰部；最大横向扩张位移和竖向收敛位移分别为2.13 mm和4.56 mm。主隧道管片环间螺栓最大拉应力为213 MPa。3）背推式反力模式更利于控制开口处的横、竖向位移，反拉式反力模式更利于控制开口对面管片应力变形及其接缝处错动位移。
To examine the mechanical
response of a metro shield tunnel during the construction of a cross-passage using the front-traction pipe
jacking method, a finite element model based on a Beijing metro shield tunnel
is established to simulate the construction process. The model′s accuracy is validated by comparing simulation results with field
monitoring data. The effects of cross-passage
construction on the dislocations between rings, stress and deformation of
special segments, and bolt force are studied. Meanwhile, the effect of
different reaction modes on the mechanical characteristics of shield tunnel are
analyzed. Key findings include the following. (1) Opening a special segment
significantly affects the mechanical properties of the shield tunnel; the stress
and deformation increase gradually with the excavation of the cross-passage. (2) The maximum displacement between segments is recorded
as 1.17 mm, occurring at the bottom of the joint between the special and
ordinary segments. The highest tensile stress in the special segment is 18.6 MPa at the top
and bottom of the opening, whereas the maximum compressive stress is 27.0 MPa
at the waist of the opening. The maximum transverse expansion and vertical
convergence displacement of the special segment are 2.13 and 4.56 mm,
respectively, with the inter-ring bolt experiencing a
maximum tensile stress of 213 MPa. (3) The backthrust
reaction mode proves more effective in controlling the horizontal and vertical
displacement at the opening, whereas the front-traction
reaction mode better manages the stress and deformation of the segment and the
dislocation between rings opposite the opening.
