Experimental Study on the Effect of Temperature on the Characteristics of Cutterhead Mud Cake in Complex Red-Bed Geology

Mud caking on shield cutterhead is a critical issue for tunnel safety, and temperature and duration are factors that can affect the characteristics of mud cake. Therefore, the aim of this study is to explore the characteristics of different temperatures and action times on the adhesion and hardness of red-bed geological mud cake. A self-designed experimental apparatus was used to simulate the adhesion of mud cake on the cutterhead. The adhesion and hardness of the mud cake were analyzed through mud cake shedding tests and hardness tests. In addition, water film theory is used to analyze the adhesion mechanism of the mud cake. The results indicate that temperature and duration are key factors affecting mud cake shedding. Within the range of 25~150 °C, mud cake shedding efficiency is positively correlated with temperature and duration. However, temperatures above 150 °C promote the sintering of the mud cake, reducing its shedding efficiency. The hardness of the mud cake increases with temperatures above 150 °C, where the mud cake hardens and sinters, increasing the difficulty of shield tunneling. The water content of mud cake is influenced by temperature and time, affecting the amount of mud cake shedding. As the water content increases, the shedding initially decreases and then increases, reaching its minimum at about 30%, where the adhesion is strongest. By controlling the temperature and time, the water content can be optimized, improving the handling of mud cake.