类矩形土压平衡盾构施工附加应力分析

 采用弹性力学Mindlin解，考虑刀盘正面附加推力和不均匀壳体摩阻力，分析类矩形盾构施工引起的土体附加应力。结果表明，类矩形盾构掘进引起的附加应力具有区域特征，刀盘前方土体受压，后部土体受拉。与双圆盾构、大直径圆形盾构相比，类矩形盾构掘进引起的附加应力较小，接近大直径圆形盾构，有利于土体扰动控制。研究结果可为类矩形盾构施工地下管线保护、地层扰动控制及“单洞双线”地铁隧道盾构选型等提供参考。

Analysis of the superimposed stress of soil layer induced by quasi rectangle EPB shield tunneling

The tunneling in Ningbo，China, used the newly-developed quasi rectangle EPB shield and the superimposed stress was analyzed based on the Mindlin?s solution with the consideration of the excess pressure in front of the excavation face and the unevenly-distributed friction across the shield surface. Results show that the superimposed stresses are different from place to place in the soil layer. The soil in front of the cutter face is compressed，while the soil behind is under tension. The superimposed stresses in quasi rectangle shield tunneling are close to the ones in tunneling with the large diameter circular shield machines and are much smaller than the ones in DOT shield tunneling. The soil disturbance caused is thus easier to control.