急曲线盾构掘进对管片结构及周围环境影响的数值模拟研究

Numerical Study on the Effects of Sharp-Curve Shield Tunnelling on Segmental Lining and the Surrounding Environment

摘要: 以桃浦污水处理厂初期雨水调蓄工程急曲线盾构隧道为背景，通过三维有限元数值模拟，研究急曲线盾构施工过程中管片受力与变形特性、土体加固措施有效性以及地表沉降规律。结果表明，急曲线段盾构施工中非对称千斤顶推力导致管片发生明显的水平与竖向位移，管片变形与受力集中于曲线中段和拱腰位置，弯矩和剪力显著增大。采用偏心门式MJS土体加固后，可显著降低管片的水平位移和受力不均现象，并有效控制地表沉降的发展趋势。研究成果可为急曲线盾构隧道施工优化及周边环境保护提供理论支持与工程参考。

Abstract: Taking the sharply curved shield tunnel of the Taopu Wastewater Treatment Plant Initial Storm-Water Storage Project as a case study, a three-dimensional finite-element model is established to examine (1) The mechanical response and deformation characteristics of the segmental lining, (2) The effectiveness of ground-improvement measures, and (3) The evolution of ground settlement during construction. The results show that, in sharp-curve drives, asymmetric jack thrusts induce pronounced horizontal and vertical displacements of the lining; deformation and stress concentrate in the middle portion of the curve and at the springline, with bending moments and shear forces increasing significantly. Adopting an eccentric portal-type MJS (Multiple-Jet-System) grouting scheme markedly reduces horizontal displacements and stress non-uniformity in the lining and effectively restrains surface settlement. These findings provide technical guidance and engineering reference for optimizing sharp-curve shield-tunnel construction and protecting adjacent facilities and ground surface.