Study on the Characteristics of Slurry Support Efficiency on Excavation Face Induced by Shield Cutterhead Cutting in Sand Stratum

During the slurry shield machine tunnelling in sand stratum with strong permeability, it can be challenging to achieve the filter cake formation on the excavation face in time. The continuous damage of shield cutting tools on the filter cake is a significant contributor to the challenge of maintaining the support pressure of slurry. To investigate the influence of shield tunneling parameters on the effective support pressure of excavated face, a set of infiltration column apparatus was developed. This apparatus can simulate the rotation and driving of shield cutterhead. This apparatus has been utilized to conduct numerous tests, and a theoretical model of dynamic filter cake formation has been established. The results indicate that the water flow through the excavation face is positively correlated with the speed of driving shields and cutterhead rotation, and negatively correlated with the slurry pressure. The influence of shield driving parameters on the effective conversion ratio of slurry pressure is in contrast to the aforementioned scenario. Furthermore, the ratio of the dynamic filter cake formation area calculated by the theoretical method can serve as an index of the influence of shield driving parameters on slurry support efficiency to a certain extent.