Method for preventing shield casing jamming due to too large frictional resistance in earth pressure balance shield machine

摘要

A method for preventing shield jamming by excessive frictional resistance in earth pressure balance shield which involves real-time monitoring of earth pressure signal for earth pressure on the shield body through sensors on the shield machine. Combined with the known parameters, resistance in the shield machine is calculated. The friction F1 between the shield body and the stratum is calculated by CPU module in PLC according to the earth pressure signals on a real-time basis. Then the friction F1 is determined whether it is less than or equal to the difference between the quotient of dividing total propulsion force Ft by correction coefficient Kxz and total resistance of F2, F3, F4 and F5; if so, it is under normal propulsion; if not, the warning device alarms.

主权项

1. A method of preventing shield-jamming of an earth pressure balance shield machine caused by excessive friction in a construction comprises the steps of:
carrying out real-time monitoring of earth pressure signals for earth pressure between a shield body of the shield machine and a stratum through a plurality of earth pressure sensors arranged on a shield casing of the shield body of the shield machine; calculating a total propulsion force (Ft) of a propulsion oil cylinder of the shield machine, a head friction (F2) of a cutting disk of the shield machine, a friction (F3) between a tail seal of the shield machine and a pipe sheet, a friction (F4) between a wheel set of a backup trailer and steel rails, and an axial component force (F5) produced by water and earth pressure acted on a cutter of the cutting disk when the cutting disk has a cutting action; and inputting the total propulsion force (Ft) of the propulsion oil cylinder of the shield machine, the head friction (F2) of the cutting disk of the shield machine, the friction (F3) between the tail seal of the shield machine and the pipe sheet, the friction (F4) between the wheel set of the backup trailer and the steel rails, and the axial component force (F5) produced by the water and earth pressure acted on the cutter when the cutting disk has a cutting action together with a correction coefficient (Kxz) into a CPU (Central Processing Unit) module of a PLC (Programmable logic controller) through a programming device; and simultaneously inputting the earth pressure signal detected by the earth pressure sensors into the CPU module through an input module; then calculating the friction (F1) between the shield body and the stratum based on the earth pressure signals detected by the earth pressure sensors; and finally determining whether the friction (F1) between the shield body and the stratum is less than or equal to a determining value, which is the difference between a quotient of dividing the total propulsion force (Ft) of the propulsion oil cylinder of the shield machine by the correction coefficient (Kxz) and the total resistance of F2, F3, F4 and F5; if the friction (F1) is less than or equal to the determining value, then the shield machine is determined to have a normal condition; if the friction (F1) is greater than the determining value, then an alert device is triggered to shut down the shield machine such that engineering measures for pretreatment of stratum, auxiliary engineering measures or both of the engineering measures for pretreatment of stratum and the auxiliary engineering measures are employed to prevent shield-jamming and forced shut down of the shield machine.