Abstract: In cohesive strata, earth pressure balance shield tunneling often encounters issues such as mud cake formation and cutting edge blockage. These problems not only hinder the efficient discharge of excavated material, leading to decreased excavation efficiency, but also increase the risk of frequent silo openings during the construction process. Furthermore, heat generated during excavation can affect soil adhesion. To explore the adhesion effects on the cutter head considering cutter head temperature, water content, clay content, clay type, and other factors, a self-developed rotary adhesion test system for the cutter head was employed. The system also examined the preventive and control effects of foam agents and anti-adhesion agents at different mixing ratios to mitigate blockage. The findings indicate that an increase in temperature reduces rotational torque and soil adhesion on the cutter head's surface, but it accelerates clay hardening. The trends of soil moisture content and clay content on torque are inverse, yet they similarly affect adhesion. As moisture content or clay content increases, adhesion initially increases and then decreases. The highest adhesion occurs at 20% moisture content and 30% clay content. Furthermore, bentonite exhibits greater adhesion compared to kaolin. The adhesion effects of soil moisture content, clay content, and clay type can be assessed using a consistency index. As consistency increases, adhesion initially increases and then decreases. The soil shows the highest adhesion when the consistency index ranges between 0.5 and 0.75, and low consistency index soil is more temperature-sensitive. While the addition of foam agents alone decreases soil adhesion, substantial adhesion persists at a 70% injection ratio. However, a 50% injection ratio shows better improvement with the combined use of foam agents and anti-adhesion agents. Additionally, increasing the injection ratio has minimal impact on soil improvement. These findings offer valuable guidance for evaluating blockage risks in earth pressure balance shield tunneling through cohesive strata and choosing suitable soil improvement strategies for cohesive soil remnants.

Key words: earth pressure balance shield, cutter head clogging, viscous formation, temperature effect, muck improvement