超浅埋大跨双连拱隧道三导洞+洞盖法施工变形特性分析

以厦门第二西通道(海沧隧道)超浅埋下穿兴湖路段双连拱隧道为依托,提出三导洞十洞盖法施工工法;采用数值模拟,研究施工工序对双连拱隧道中隔墙、边墙、初支及衬砌的变形影响规律.结果 表明:中隔墙及侧墙竖向位移在左右洞上台阶贯通后达最大值,当开挖预留核心土及中、下台阶时,中隔墙及侧墙均产生向上的隆起;开挖对中隔墙水平位移影响较...

Analysis of Construction Deformation Characteristics of Ultra-shallow Buried Large-span Double-arch Tunnel with Triple Pilot Tunnels + Cave Cover Method

Based on the super-shallow buried double-arch tunnel of Xiamen Second West Passage ( Haicang Tunnel ) crossing Xinghu Road Section, the construction method of triple guide tunnel + tunnel cover has been innovatively put forward, and numerical simulation is used to study the influence of construction procedure on the deformation of middle partition wall, side wall, primary support and lining of double arch tunnel. The results show that the vertical displacement of the middle partition wall and the side wall reaches the maximum value when the upper steps of the left and right holes are connected. When the reserved core soil and the middle and lower steps are excavated, the middle partition wall and the side wall both have upward uplift. Excavation has little influence on the horizontal displacement of the middle partition wall, while the excavation of the upper steps of the left and right holes has a great influence on the horizontal displacement of the side wall. The vertical and horizontal displacements of the top of the left wall are quite different from those of the bottom, leading to the tendency of the left wall to deflect towards the outside of the tunnel. The vertical and horizontal displacement of the primary supports on the first and second layers reaches the maximum value and tends to be stable after the upper steps of the left and right holes are connected, while the excavation of the middle and lower steps has little influence on the vertical and horizontal displacement.