Three‐Dimensional Numerical Simulations of Large‐Diameter Slurry Shield Tunnelling: The Influence of a Dynamic Filter Cake

ABSTRACT A refined simulation of slurry shield–ground interactions should consider the dynamic and heterogeneous filter cake created by slurry infiltrating and tool cutting. Previous studies often neglect the influences of dynamic and heterogeneous filter cakes on tunnelling‐induced ground responses. This study utilizes slurry infiltration column tests to derive the infiltrating depth and the time‐dependent permeability of the slurry‐penetrated zone, which is further incorporated into a fluid–solid coupling numerical model to simulate a heterogeneous and dynamic filter cake. The proposed numerical model successfully reproduces the measured ground deformations and pore pressures in Zhuhai tunnel. It is found that the excess pore pressure rises sharply within a range of 0.5 times the tunnel diameter when a cutter disturbs and cuts through the filter cake, and then gradually dissipates as the filter cake reforms and regains its low‐permeability structure. Moreover, more remaining filter cake leads to stronger pressure reduction and smaller ground deformation. A higher cutter opening ratio reduces the slurry pressure‐transfer efficiency, while a more non‐uniform distribution of disc cutters leads to a more rapid stabilization of the pressure‐transfer process. Numerical simulations without considering fluid–solid coupling tend to overestimate the filter cake's pressure‐transfer efficiency and underestimate ground deformations, yielding a maximum settlement about 15% lower than that from the coupled analysis. These results demonstrate that three‐dimensional numerical simulations considering dynamic filter cakes and fluid–solid coupling enable more accurate reproduction of shield–ground interactions.