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针对富水区土压平衡式盾构隧道施工进行了水-力耦合(H-M耦合)数值模拟。首先在既有的研究成果基础上建立了单元状态指标ZSI(Zone State Index),该指标将屈服、破坏接近度等进行适当变换,统一到单元安全度量体系(负值代表破坏),实现了单元的弹性、屈服和破坏3种状态的完整表达。然后将应变-渗透系数方程与ZSI结合,使渗透系数在耦合的过程中随单元状态发生改变,弥补了FLAC~(3D)渗流模拟中渗透系数不变的不足。最后采用FLAC~(3D)的FISH语言二次开发,以大连地铁202标段香工街站-沙河口火车站区间盾构地铁隧道为例,实现H-M耦合过程的模拟。分析了隧道掘进的过程中开挖面及围岩的变形和破坏特征,根据开挖面上ZSI的计算结果对开挖面进行了稳定性评价。研究结果表明,该方法可以较好地进行H-M耦合过程中模拟和分析,与实测结果较为吻合。
The water-force coupling (H-M coupling) numerical simulation is carried out for the earth pressure-balanced shield tunnel construction in the rich water area. Firstly, ZSI (Zone State Index) is established based on the existing research results. The index transforms the yield and failure proximity to the unit safety metric system (the negative value represents the damage), and the unit The elasticity, yield and destruction of the three states of the complete expression. Then, the strain-permeability coefficient equation is combined with ZSI so that the permeability coefficient changes with the unit state during the coupling process, which makes up for the lack of permeability constant in the FLAC 3D flow simulation. Finally, the FLAC 3D reconstruction of the FISH language was used to simulate the H-M coupling process, taking the shield tunnel section of Xiangong Street Station-Shahekou Station in the section 202 of Dalian Metro as an example. The deformation and failure characteristics of the excavation face and the surrounding rock during tunneling are analyzed. The stability of the excavation face is evaluated based on the ZSI calculation results of the excavation face. The results show that this method can simulate and analyze the H-M coupling process better, which is in good agreement with the measured results.