西安地铁左右线交叠转换盾构施工变形规律研究

摘要

交叠隧道在施工过程中对周围地层存在反复扰动，针对其力学行为和变形规律的研究十分有必要。以西安地铁临潼线左右线交叉叠落盾构隧道施工为背景，研究线路左右线隧道空间交叉转换施工下周围地层的变形规律及后施工隧道（左线）对已完成隧道（右线）的扰动情况。研究表明：隧道施工完成后，地表沉降槽整体呈条带状且沿区间走向分布；地表沉降随隧道垂直交叠程度的增加而增加，地表沉降最大值为9．79 mm，位于左右线完全垂直交叠位置处；左线隧道对先施工完成的右线隧道的影响主要表现为侧向推挤和增大地层附加应力的作用，但在垂直交叠位置扰动影响较小；施工扰动引起右线隧道最大水平位移为1．75 mm，最大沉降为1．97 mm。%The ground is often affected by the construction of overlapping shield tunnels,as a result,it is necessary to study the mechanical behavior and deformation rules caused by the interaction in the construction of overlapping tunnels. In the paper,the rules of the deformation of surrounding ground induced by the construction of the overlapping shield tunnels on Lintong Line of Xi’an Metro,as well as the rules of the influence of the construction of the left tunnel tube on the constructed right tunnel tube,are studied.The result shows that:1)After the construction of the overlapping tunnel is completed,the ground surface settlement trough induced by the construction of the tunnels,which takes a belt shape, is distributed alone the tunnel.2)The ground settlement increases as the degree of the vertical overlapping magnitude increases;the maximum ground surface settlement reaches 9.79 mm at the fully vertical overlapping point;3)The influence of the construction of the left tunnel tube on the constructed right tunnel tube takes the form of lateral pushing and increasing the strata supplementary stress.At the vertically overlapping section,such influence can be ignored.The maximum horizontal displacement of the right tunnel tube induced by the construction of the left tunnel tube reaches 1.75 mm,and the maximum settlement of the right tunnel tube reaches 1.97 mm.