Study on the operation procedure and driving mode

TB880E roadheader operation procedure and selection of tunneling mode

[Abstract] this paper mainly introduces the operation procedure of TBM under different working conditions, especially expounds the tunneling mode and parameter selection under various surrounding rocks, which plays a guiding and normative role in the operation of TBM

tbm construction method is the first time to apply the latest tunnel construction method in 2013 and 2014 in the system of the Ministry of railways. It is a systematic and industrialized operation mode, and each link is interrelated. If one link fails, the whole construction will stop. For the TB880E roadheader with a total length of 252m, it has high technical content and complex operation. 90% of its instructions are issued by the main control room. Any misoperation will affect the construction or cause major accidents. Therefore, it is very important to operate correctly and select the tunneling parameters reasonably

1 choose the best experimental instruments and equipment from various existing scientific and technological plans (special projects, funds) or free funds. Under normal circumstances, the operation procedure

(1) an alarm should be sent before starting the equipment, so as to attract the attention of personnel in different operation areas and prevent accidents

(2) start the high-pressure water pump and cutter head water spray pump station

(3) start No. 7, 8, 3, 5, 1, 6, 9 and 2 hydraulic pump stations in turn

(4) start all ventilation, dust removal and refrigeration systems

(5) select the high/low speed (5.4r/min/2.7r/min) of the cutter head according to the geological conditions, select the soft start of the motor, and the soft starter controls the interval time and current change of the motor start

(6) start 8 main motors, and the interval between them is 1min; When h main motors are not started, start belt conveyors 3, 2 and 1 at the same time

(7) after the motor operates normally, start the cutter head rotation, but pay attention to the current change of the motor. If the current remains high, stop the cutter head rotation immediately and check the electrical equipment

(8) start tunneling: select manual control and adjust the tunneling speed to 20%. After the tunneling parameters are relatively stable and the actual tunneling is 5cm, start to increase by 10 percentage points to improve the tunneling speed; When the propulsion oil pressure reaches 25.ompa and is basically stable, the tunneling speed should be increased by 5 percentage points until the propulsion oil pressure reaches the rated value (26.5mpa)

(9) after one cycle of tunneling (1.8m), retreat the cutter head 3cm, stop the cutter head rotation after the cutter head idles for 1cm, stop the motor and belt conveyor in sequence, and carry out step change operation; Put it down first and then support it until the pressure shows 15.ompa; Loosen the shield clamping cylinder and put down the front support until the pressure shows 10.ompa; Then loosen KAI 1 and Kai 2 and observe the pressure display until the retraction pressure of the support shoe in the automotive field is 18.ompa and the extension pressure is OmpA; Move Kay 1 and Kay 2 forward and make sure they are in place. Then adjust the left, right, upper and lower deviations of TBM according to the zed guidance system. During the adjustment, because the laser detection is slow, the operation can be carried out after the data display is stable, and each adjustment shall not exceed 3 dishes. After the direction adjustment, hold KAI 1 and Kai 2 tightly. Generally, the holding pressure is 28.ompa. If the dry compressive strength of surrounding rock is low, the holding pressure is generally 27.5mpa, which is not allowed to exceed 28.ompa. Otherwise, it will collapse local surrounding rock, causing the support shoe to slip. After the support shoes are braced tightly, take back the front and rear supports, move the rear support forward, and then support after dragging

(10) everything is ready for normal tunneling in the next cycle

2 reaming operation and parameter adjustment

the reaming operation is carried out when the side knife needs to be changed. Only one reaming knife is needed each time, and the reaming diameter is 8.9m. The process is as follows:

(1) the technology they are developing can return our ordinary plastic waste to the cutter head by 1m

(2) check and confirm that the reaming operation room operates normally. Flexibility

(3) check and confirm that the reaming oil cylinder and the reaming knife are flexible

(4) select the motor to rotate the cutter head at high speed, and constantly extend the reaming knife, so that the reaming knife slowly contacts the rock wall

(5) the reaming speed is controlled at 10% at the beginning. After 5cm of tunneling, the speed can be adjusted to 10% - 20%, and the maximum is no more than 25%

(6) the reaming length is generally between CD-80. During the reaming operation, it is necessary to constantly add oil to the reaming cylinder; Maintain the extension pressure of 20.ompa

(7) after the reaming is completed, recover the reaming cylinder, stop the machine, retreat the cutter head by 20cm, and replace the side knife or scraper

3 selection of tunneling mode

tbm has three different modes to choose from in the process of tunneling operation, namely, automatic thrust control mode, automatic torque control mode and manual control mode. The operator should decide which working mode to choose according to the rock condition

(1) when excavating under the condition of homogeneous hard rock, select the automatic control thrust mode, the equipment will not be overloaded, and can ensure a high tunneling speed. The judgment basis for selecting this working mode is: when driving, the propulsion force reaches the maximum value first, but the torque does not reach the rated value, then the surrounding rock can be determined as hard rock state, and the automatic control thrust mode is selected

(2) when driving under the surrounding rock with developed joints, the thrust of the equipment will not be too large, but the torque of the cutter head is very high, so the automatic torque control mode should be selected. The judgment basis for selecting this working mode is: during tunneling, the torque first reaches the rated value, but the propulsion force does not reach the rated value or reaches the rated value at the same time, there is no large ballast output on the belt conveyor, and the surrounding rock can be determined as homogeneous soft rock state, so the automatic torque control mode is selected

(3) if the state of surrounding rock cannot be determined, or the hardness of surrounding rock changes unevenly, joints are developed, and there are fracture zones and faults, the manual control mode must be selected

a. in the process of manual control mode operation, if the surrounding rock is hard, the propulsive force reaches the rated value first. At this time, the excavation parameters should be selected based on the change of propulsive force, but the propulsive pressure should not exceed 26.5 MPa

b. in the process of manual control mode operation, if rock joints are developed. There are many cracks or fracture zones, faults, etc. The driving parameters are mainly selected based on torque changes and propulsion parameters, but the single machine current