基坑分段开挖下部盾构隧道纵向变形规律研究

为研究基坑分段开挖时下部盾构隧道的纵向变形规律,以某分段开挖基坑小角度斜跨盾构隧道工程为例,采用对比法和归纳法,通过数值模拟分析,得出基坑分段开挖时下部盾构隧道纵向变形规律.研究表明:(1)基坑分段越越短,其下部盾构隧道最大隆起位移值越小,隧道隆起范围越小;(2)开挖分段个数与隧道隆起位移峰值个数相同,分段越均匀,峰值...

Study on the Longitudinal Deformation Law of Shield Tunnel During the Segmented Excavations of Foundation Pit

In order to study the longitudinal deformation rule of the shield tunnel under the excavation of foundation pit,taking an excavation case of a foundation pit which has a small intersection angle with the shield tunnel as an example, the longitudinal deformation law of the shield tunnel is discussed by applying comparison and induction methods through numerical simulation analysis. Research shows:( 1) If the excavation section of the foundation pit is shorter,the maximum uplift displacement value of the shield tunnel and the uplift range of the tunnel are shorter;( 2)The number of excavation sections is the same as the number of peaks of tunnel uplift displacement. The more uniform the segmentation,the closer the peak values.( 3) Priority should be given to the excavation of the overlapping area rather than sides;( 4) The unidirectional adjustment ratio of each adjacent part of the tunnel to each other’s deformation is about 5. 71%. The position of the maximum uplift displacement of the tunnel could be adjusted by adjusting the segmental excavation sequence.