考虑地层损失的盾构隧道土体变形修正解析解

在计算盾构隧道开挖引起的土体变形中,地层损失是十分重要的因素,而经典Loganathan公式中关于地层损失分布函数的计算仍然存在一定缺陷。根据极限平衡原理和隧道周围统一土体移动模型对Loganathan公式中的地层损失分布进行修正,而后将解析计算公式向三维空间予以拓展。通过对工程实例计算分析发现,与Loganathan公式得到的结果相比,修正公式算得的地表沉降槽宽度较小、土体水平位移也较小,计算结果更为准确,与工程实测数据更加吻合。

Refined Analytic Solution to Soil Deformation Induced by Shield Tunnel Excavation in Consideration of Ground Loss

Ground loss is an important factor in the calculation of soil deformation caused by shield tunnel excavation. In line with the limit equilibrium principle, the distribution of ground loss in Loganathan’s formula was revised using a uniform ground movement model. A refined analytic solution was derived and expanded to three-dimensional space. As shown by case analysis, the present solution obtains smaller width of surface settlement troughs and horizontal displacements of soil compared with Loganathan’s formula. The results of the refined solution are more consistent with field observations.