中隔墙对上海轨道交通16号线大断面盾构隧道的变形影响分析

上海市轨道交通16号线地下区间首次采用内径为10.4 m并设置中隔墙的"单洞双线"大断面盾构隧道。为了避免中隔墙的设置对隧道管片结构产生不利影响,中隔墙顶部与隧道结构之间需预留一定的间隙,即采用分离式设计。针对管片自身重力、地层荷载和地层固结沉降3种不同荷载类型,分别采用弹性铰圆环法、弹性地基梁法和连续介质有限元法计算管片的变形量,讨论隧道管片接头的转动刚度取9 800 kN·m/rad和19 600 kN·m/rad 2种情况。计算结果表明,隧道管片与中隔墙之间的间隙值应取为10~15 cm为宜。

Case Study on Influence of Separation Wall on Deformation of Large Cross-section Shield-bored Tunnel on No.16 Line of Shanghai Metro

The running tunnel of No. 16 Line of Shanghai Metro is a 10.4 m diameter single tube shield bored tunnel with separation wall. Separate design, i.e., some space being reserved between the top of the separation wall and the segment structure of the tunnel, should be adopted, so as to avoid the negative influence of the separation wall on the tunnel segment structure. In the paper, the deformation of the segment ring is calculated by means of elastic hinge ring method, elastic foundation beam method and continuous medium finite element method, considering tunnel segment dead load, ground load and ground consolidation settlement. Two cases, i.e., the rotation rigidity of the segment joints being 9 800 kN•m/rad and that being 19 600 kN•m/rad, are discussed. The calculation results show that the optimum space between the segment and the separation wall should be 10 cm to 15 cm.