Experimental Study on Consolidation and Hardening of Mud Cake of Shield Cutterhead in Cohesive Stratum

The cutterhead is prone to mud cake problems when the shield is tunneling in the cohesive stratum. In severe cases, the cutterhead is blocked to reduce the shield tunneling efficiency and affect construction safety. During the process of the slag adhering to the cutter head, it is accompanied by the solidation and hardening of the mud cake. To find out the influencing factors of consolidation and hardening of mud cake in shield cutterhead, laboratory tests are carried out by using a self-made cutter head tunneling simulation device. The relationship between soil properties, temperature, cutterhead earth pressure, and consolidation and hardening characteristics of mud cake is studied. The experiment of soil conditioning is carried out to explore the influence of different soil conditioners on the degree of consolidation and hardening of mud cake. The results show that the water content and cone penetration depth of mud cake can characterize the consolidation and hardening characteristics of mud cake. The properties of the soil have the greatest influence on the degree of consolidation and hardening of the mud cake formed by the cutterhead after excavation, followed by the temperature, and the cutterhead earth pressure has stratigraphic differences on the degree of consolidation and hardening of the mud cake. The foam agent has an obvious effect on the consolidation and hardening of pure clay and sand-containing clay cake, while the dispersant only has an obvious effect on pure clay.