Abstract: A realtime monitoring system is developed for the mucking temperature of the earth pressure balance shield. The temperature sensors are installed on the bulkhead, screw conveyor, mucking outlet, and belt conveyor to monitor the mucking temperature in real time. Subsequently, the data are transmitted to the programmable logic controller(PLC) interface of the shield for realtime display and recording. The system was implemented in a project of the branch line of Shenzhen metro line 6 for the first time. The applicable results are as follows: (1) The proposed system can monitor the temperature fluctuation ahead of the cutterhead in real time with good stability. Moreover, the previous data in the PLC operation interface can be queried conveniently, showing a high automation degree. (2) There is a temperature difference of approximately 0.5 ℃ ~ 1 ℃ among various monitoring points, and the change in stratum property lead to changing the mucking temperature. (3) In the cohesive soil layer and strongly weathered rock layer, mucking temperature below 35℃ can be defined as normal; from 35℃ to 45℃ can be defined as a warning signal; and above 45℃ can be defined as abnormal, in case of what, the mud cake phenomenon should be estimated comprehensively based on the torque, thrust, and tunneling speed changes.

Key words:  , earth pressure balance shield, monitoring system, mucking temperature, mudcake