深基坑对紧邻地铁车站及盾构隧道的影响

Influence Analysis of Deep Foundation Pit on Adjacent Subway Station and Shield Tunnel

为研究深基坑对邻近地铁结构的影响,通过软土地区的工程实例,详细记录了基坑开挖引起的地铁车站和盾构隧道的变形过程.发现车站变形主要表现为上抬和背向基坑倾斜,位于基坑侧方底部以上的隧道变形主要表现为下沉,而车站和隧道相接处的沉降差表现明显.隧道水平收敛随基坑开挖明显增大,表现为横鸭蛋效应,可简化为平面应变问题进行分析评估.隧道收敛变形和坑外深层土体变形是后续研究的重点.

In order to study the influence of deep pit on adjacent subway structures, the practical engineering example on soft soil area is presented, with a detailed record on the deformation process of subway station and shield tunnel caused by excavation, it is concluded that the station deformation mainly performs as an uplifted effect and an inclination opposite to the foundation pit. The tunnel deformation at the bottom of the foundation pit is sinking, and the joint area of the tunnel and station bears obvious differential settlements. In addition, along with the foundation pit excavation procedure, the horizontal tunnel convergence increases obviously, which can be characterized as a transverse duck egg effect, and therefore can be simplified as a plane strain problem. In our future study, the most challenged problem is the tunnel convergence deforma-tion and deep soil deformation of the outside pit.