Tunnel lining formwork safety operation procedures

Double-track railway lining trolley

Tunnel lining formwork is a special equipment that must be used in the secondary lining of tunnel construction process. It is used for lining construction of the inner wall of the tunnel. There are mainly simple lining trolleys, full hydraulic automatic walking lining trolleys and grid-type lining trolleys. Tunnel lining formwork should follow the corresponding safety procedures during the construction process.

First, the operator’s job requirements

1. The operator should do a good job in the inspection and maintenance of the daily use of the tunnel lining trolley, and make necessary records.

2. It is strictly forbidden to operate according to the safety technology and the corresponding operating procedures.

Second, the job conditions

1. The operator should have received good safety and technical training. Hold the certificate and work.

Third, pre-job preparation

1. After the lining trolley is assembled, each connecting screw should be inspected and tightened one by one, and can be put into use after being inspected and accepted by all parties.

2. Wear belts on the lining trolley. The operating parts should be covered with 5cm planks to prevent the workers from falling from high places. The trolleys are equipped with eye-catching reflective strips.

Fourth, the safety procedures

1. The base surface of the lining trolley track should be solid and flat. It is strictly forbidden to be soft on the side and the top surface of the track should be on the same plane. The track pitch is consistent with the wheel edge of the platform.

2. The top surface of the lining trolley track is basically parallel with the longitudinal excavation surface of the tunnel. When the slope is large, the railing device should be installed at a position of not less than 3m at the track head to prevent the lining trolley from derailing during operation.

3. When the lining trolley moves in position, when there is automatic downward sliding, the operator should select an experienced person to operate, and send people on both sides of the forward direction to check the operation. When an abnormal situation occurs, the operator is notified at any time. Immediately brake the lining trolley. When the external force (loader, excavator) moves, it is necessary to use a qualified wire rope to drag along the uphill direction of the tunnel, slowly slide and move, let it move under the action of gravity, and it is strictly prohibited to lining the trolley in the direction of the slope.

4. The trolley should be slow and stable during the movement. When the movement is difficult, it should be carefully checked whether there are hard objects stuck on the two sides or the bottom of the trolley. Check whether there are steel intrusion restrictions on both sides and the top surface to hinder the running of the trolley. The trolley should be stopped, and the collapse of the steel skeleton will occur.

5. After the trolley is positioned, the operator should first wedge the wheel with a wooden wedge and then adjust the trolley under the command of the surveying personnel. When the offset of the trolley is large, the cylinder should be adjusted symmetrically. Make the trolley position reach the balance requirement. When the positioning of the trolley meets the requirements, the screw jacks on the bottom of the trolley should be tightened first, and then the jacks on both sides of the trolley should be screwed tightly. When the tops of the trolleys are tightened in place, the hydraulic cylinders are loosened. Open to protect the cylinder.

6. Before pouring concrete, the operators should check the jacks one by one to ensure that each screw jack is tightened and the top of each hydraulic jack is relieved. In the process of concrete pouring, it should be strictly symmetrically poured. The height difference between the concrete on both sides should not exceed 1 m, 0.5-0.8 m is appropriate, and the jack should be sent to check. When the concrete structure is thick and the square is large, the pouring speed should be slowed down in a timely manner, and the frequency of the mold should be tightened to prevent accidents such as running, rising and falling.

7. The power supply control box of the trolley should be placed on the base surface of the tunnel. It is strictly forbidden to install the control electric box on the trolley. All the power cords must pass through the leakage protector. The action current should not exceed 30MA, and the action time should not exceed 0.1S. The cable must be made of rubber flexible cable, and there must be no joints or damage in the middle. The frame body must have a reliable protection and zero connection.

8. The lighting on the trolley should use an electric voltage or a flashlight.

Five, other matters needing attention

1. When a vehicle passes under the clearance of a trolley during construction, it shall be assigned to conduct traffic command and management to prevent vehicles from colliding with the trolley.

2. Strictly control the center line of the rail to avoid excessive deviation between the center of the backstage vehicle and the center of the tunnel.
3. During the laying process of the rails, the rails and rails must be firmly connected to avoid the rails being crushed or the trolleys derailed during the running.

4. Remove the imaginary underneath the sleeper to avoid sinking due to the weight of the raft and the trolley.

5, the head plate is stressed, the reinforcement must be reinforced in the process of standing, in the process of pouring, there are people to see, strengthen at any time.

6. The second lining is poured for a long time. In order to facilitate the simultaneous construction of the second lining and the shovel, the pump is placed away from the lining trolley.

7. The conveying pipe is fixed firmly on the gantry. The pipe should not be in contact with the stencil, so as to avoid strong vibration at the nozzle when the squeezing is pressed out, so that the stencil can be deformed and run. The joint pipe clamps should be connected firmly to avoid explosion. The pipe squares are raised above the ground. When passing through the trolley, the pipe clamps are not in direct contact with the trolley components.