In the actual pushing process of the cement jack pipe, it is impossible to be completely in the above-mentioned ambition. If the pushing speed is faster than the soil discharge speed, we will push and stop, and insist on pushing forward; otherwise, the screw conveyor can be started and stopped . In either case, it is necessary to keep the earth pressure in the silo within the range of controlled soil pressure P20KPa, which can ensure the equilibrium of the earth pressure. If the earth pressure in the silo is less than the active earth pressure, the ground will sink. On the contrary, the ground will arch. Therefore, the control of the setting of the earth pressure and the persistence of the earth pressure in the silo are the key.
Measurement and direction control: The jacking measurement and direction control is to use a laser theodolite supplemented by a level gauge to measure, and then correct it through the oil cylinder. Follow the principle of first correcting the upper and lower, then correcting the left and right.
Strict stakeout review system and original records. It is necessary to prevent displacement and deformation of the instrument base arranged behind the operating well, and it is necessary to repeat the measurement and adjust it in time. It is necessary to measure and make fine adjustments for the jacking correction, and the correction angle should be kept at 10 ′ ～ 20 ′ and not more than 1. During the initial propulsion phase, the direction is mainly controlled by the main cylinder. Therefore, on the one hand, the main cylinder driving speed must be slowed down, and on the other hand, the cylinder group and the nose must be adjusted continuously. Before each jacking operation is carried out, the jacking machine must first formulate a design and adjustment of the slope, which is also to achieve the satisfactory quality of the customer.
Power supply arrangement of the cement pipe jacking machine: There are two main ways of using electricity in the jacking process of the cement pipe jacking machine. One is the power electricity, that is, the power supply, and the other is the lighting electricity mode, that is, the lighting electricity; The motor in the pipeline uses 380V power. Therefore, it is necessary to perform secondary maintenance and grounding maintenance measures for the power that enters the pipeline. The power power line is set at a place where operators are not easily accessible, and a sheath is added outside the power line to ensure Electrical safety; lighting power: Because the air humidity in the pipeline is relatively large, 36V low-voltage lighting power is used, and the low-voltage power must be reduced by a transformer. The lamps and lanterns use waterproof and explosion-proof lamps.
Ground surface sinking control: This jacking machine uses earth pressure balance, which can first calculate the active earth pressure and passive earth pressure at the excavation center of each jacking section, and then set the earth pressure of the tunneling machine to this active earth Between the pressure and the passive earth pressure; when the cutter head is cutting and mixing, the main roof and the relay are slowly pushed, and the earth pressure in the silo will gradually increase. When the earth pressure rises above the control earth pressure P, The screw conveyor is opened, and a part of the soil is discharged by the screw conveyor. As long as the pushing speed is adjusted to match the amount of soil discharged by the screw conveyor, the earth pressure can be maintained at a constant value.