The bridge expansion joint is located at the movable end of the bridge superstructure and the bridge deck fracture joint, which is mainly composed of the force transfer support system and the displacement control system. The expansion joint of the bridge can be expanded from the self contained, and the vehicle does not need to be hit. The relatively small noise is the main function of the expansion joint of the bridge.
In order to prevent the structure from cracking and damage due to the change of climate temperature, expansion joints (C-type bridge expansion joints) are set between the beam ends and between the beam ends and the abutment. The expansion joints (C-type bridge expansion joints) are parallel to and perpendicular to the two directions of the bridge axis, which can expand and expand freely and firmly, so that the vehicle can run smoothly and without noise.
The bridge expansion joint is very important in the * * * bridge engineering to meet the deformation of the bridge. It usually extends between two beams, and needs to be extensible and fine angle extension in the horizontal and vertical directions.
The feature of GQF expansion device is that it separates the weighing structure from the displacement control system, changing the usual supporting method in the past: the structure that all center beams are supported on the same beam in one displacement control box. The number of beams is reduced and the volume of displacement control box is reduced. The device is particularly suitable for large displacement bridges.
Selection conditions of expansion device
The following documents shall be provided to the Company after GQF and C expansion devices are selected for the design of bridge beam;
A. Cross section drawing of design bridge beam: including detailed design data such as position and size of cross slope, sidewalk, safety belt and handrail.
B. Temperature and change range of expansion device during actual installation.
C If there are other special design requirements, they shall be described in detail.
The metro shield cord rubber plate is also called tunnel door cord rubber plate, cord seal ring, cord rubber plate, cord seal gasket, rubber cord plate, etc. It is the sealing device used for the entrance and exit of the shield machine at present. It is molded from neoprene through a vulcanizer. The radial and horizontal nylon wires ensure that the cord will not be broken. It is divided into circular and rectangular, with diameters ranging from 4m to 12m.
The working principle of the metro shield cord rubber plate is as follows:
The rubber plate of metro cord fabric is the sealing equipment of shield machine and pipe jacking machine when they enter and exit the tunnel, which is made of neoprene. Ensure that the shield machine can enter the tunnel safely, stably and quickly from the starting shaft of the shield machine to avoid soil collapse at the tunnel portal and water leakage at the tunnel portal. Theoretically, the greater the tensile ratio of the inner edge of the cord rubber plate, the closer the rubber plate is to the shield machine, and the better the sealing and water sealing effect. When the shield exit is sealed, the rubber plate will be close to the sector plate under the effect of water and soil pressure in front. This sealing condition is relatively reliable. Therefore, the sealing effect of the cord fabric under the exit does not need to rely on the stretching of the cord rubber plate to keep close to the shield shell. The rubber sheet has a certain tensile rate, which is generally about 2.88 in engineering applications. If the tensile rate is exceeded, the rubber sheet will be torn and damaged
The use of conveyor belts in high temperature environment is an indispensable part of many industrial production processes. However, the high temperature environment will affect the efficiency and life of the conveyor belt to some extent. In order to improve the efficiency of high temperature resistant conveyor belt, here are some tips to help you achieve the desired results.
It is very important to choose the right materials. In high temperature environment, conveyor belt materials need to have good heat resistance. Common high-temperature resistant materials include polytetrafluoroethylene (PTFE), silicone rubber, acrylate rubber, etc. These materials have good high temperature resistance and wear resistance, and can maintain good use effect in high temperature environment.
Correct installation and maintenance is also the key to improve the efficiency of high-temperature conveyor belt. During installation, it is necessary to ensure that the conveyor belt is properly tensioned to avoid slack or over tightening. At the same time, regular cleaning and lubrication of the conveyor belt can reduce the friction resistance and improve the conveying efficiency. In addition, the service life of the conveyor belt can be effectively extended by regularly checking the connection and support device of the conveyor belt, and timely finding and solving problems.
Reasonable design of conveying system can also improve the efficiency of high-temperature resistant conveyor belt. When designing the conveying system, factors such as transmission mode, transmission wheel diameter and support mode need to be considered to reduce the running resistance of the conveyor belt and improve the conveying efficiency. In addition, for long-distance conveying system, multiple driving devices can be considered and evenly distributed on the conveyor belt to reduce the load of single driving device and improve the stability and reliability of the whole system.
Regular temperature monitoring and recording is also an important means to improve the efficiency of high temperature resistant conveyor belts. By monitoring the temperature change during the operation of the conveyor belt, abnormal temperature conditions can be found in time and corresponding measures can be taken to adjust. At the same time, the operation temperature data of the conveyor belt is recorded, which is helpful to analyze the operation, find problems in time and solve them.
Improving the efficiency of high temperature resistant conveyor belt requires comprehensive consideration of material selection, installation and maintenance, system design, temperature monitoring and other aspects. Only when these aspects are in place, can the goal of improving efficiency and extending service life be truly achieved. I hope the above tips can help you in your practical work
