Construction lifts have become indispensable in the construction process of high-rise buildings because they can transport construction workers and materials vertically, greatly reducing the labor intensity of construction workers and effectively improving production efficiency. The equipment ensures the correct installation and use of construction lifts, discovers and solves problems as promptly as possible during production work, eliminates hidden dangers in the bud, prevents accidents, and ensures the safety of life and property. This article focuses on the use of construction lifts in Analyze some common problems during installation and use.
2. Safety technical points for the installation of construction lifts
1. Installation environment
As a dual-purpose elevator for people and cargo, the installation work of construction lifts must be carried out by the construction company A professional team with a disassembly and assembly qualification certificate issued by the administrative department is responsible. Various safety protection measures must be taken at the installation site. The distance between the moving parts of the lift and the fixed construction equipment of the building is ≥0.25m.
2. Installation of main components
(1) The height of the same column as the foundation should be not less than 1.5m, and an interlocking device should be installed. The mechanical interlocking should make the cage The basic fence door can only be opened when it is at the position specified at the bottom. The electrical interlock should make the cage stop and cannot start after the protective fence door is opened. The main power supply is not completely cut off. No one can stand on top of or against the fence in the fence. Hold on to the fence and move in unsafe areas such as the guide columns in the lift passage and the wall frames.
(2) When installation and maintenance operations are required on the top of the cage, a protective railing with a height of not less than 1.05m must be installed around the top of the cage. Use the installation boom set on the top of the cage. When working, the maximum lifting weight of the boom is 200kg. Overloading is not allowed, and the load of the cage is not allowed to exceed the rated installation load. When there are hanging objects on the boom, the cage must not be operated until all connecting bolts are fully connected. After tightening and the spreader has been removed from the newly installed standard section, the cage can be driven. When the cage is driven, the operating box must be moved to the top of the cage. Manipulation inside the cage is not allowed. When the cage is running, , the human body and transported objects must not exceed the guardrail of the cage.
(3) The joint surfaces of the upright columns of the standard section should be straight, and the step difference caused by mutual misalignment should be ≤0.8mm. The rack connection on the standard section should be firm, the butt joint should be smooth and accurate, the tooth height difference should be ≤0.3mm, and the tooth period error should be ≤0.6mm. The installation verticality tolerance of the entire height of the guide rail frame axis line to the horizontal datum plane of the base is ≤, and the erection height is 1/1000.
(4) The parking point should be equipped with a parking railing. The parking railing should not protrude into the lifting channel of the cage. The switch of the parking railing can be done manually, but it must not be directly controlled by the motion of the cage. .
(5) Measures should be taken on the guide rail to prevent the counterweight from moving. Two or more tie rods should be used to fix the counterweight. The counterweight guide rail should be straight, and the guide rail distance deviation should be ≤3mm. The guide rails should be strong and able to withstand the corresponding additional stress. When the cage stops on the fully compressed buffer, the free travel on the counterweight should not be less than 0.5m.
3. Installation common problems and countermeasures
1. Protective layer door
During the actual installation process, it is hoped that the cage will reach its operating point as soon as possible for up and down Due to the reasons of construction personnel and materials, the construction workers on the inside of the landing door often open the landing door directly and enter the running channel of the cage to call the construction elevator driver. Sometimes they even mistakenly place materials in the running channel of the cage. This This phenomenon is particularly common during busy construction phases.
If the driver of the construction lift is slightly careless, the operating cage can easily cause injuries to people entering the operating channel of the cage and cause materials to fall from the air, endangering personal safety and leading to accidents. Common problems in the production and installation of landing doors are: the control method of the landing door switch is incorrect, and it can be opened and closed by people from both inside and outside at will; simple processing and welding of steel bars is used to make the landing door, resulting in holes in the landing door. Large, people on the inside of the landing door can reach out to the outside of the landing door through the hole to operate the locking device to open the landing door; the locking tongue of the landing door locking device is too short or is locked with a simple hasp, which cannot be effective. With the locking function, the landing door can be easily pushed open on the inside of the landing door. After the landing door that meets the specification requirements is produced and installed, a complete protective facade will be formed on the exterior facade of the building with other protective facilities. Due to the holes in the landing door itself It is small and it is difficult for a person's hand to extend from the inside to the outside of the landing door to open the landing door. In addition, the locking device is reliable and effective. People on the inside of the building cannot open the landing door. Only when the construction elevator cage runs to the corresponding floor, the landing door is opened by the locking device. The person on one side of the cage opens the landing door. Before the cage leaves the docking floor, the driver should be responsible for closing the landing door and locking the locking device in place to ensure that the landing door is reliably closed. The landing door can only be opened by the cage. The opening and closing of the landing door can be handed over to the construction lift driver, which avoids the phenomenon of the construction lift driver and the construction personnel passing the buck. This brings convenience to the equipment management work, and the operations can be combined when necessary. The procedures and management systems conduct quantitative assessments on their work and establish corresponding reward and punishment measures to truly achieve effective management and ensure the safe use of equipment.
2. Foundation
During the installation and use process, once there are serious consequences such as cracking and damage due to insufficient load-bearing capacity of the underground roof, it will cause great economic losses. According to actual Experience shows that when the foundation needs to be installed on an underground engineering project slab, the foundation position should be designed as far as possible above the main stress-bearing parts such as beams and columns. Secondly, the load-bearing capacity of the roof of the underground engineering project should be combined with the construction drawings based on the civil construction drawings. Compare all the loads of the elevator under the most unfavorable working conditions to ensure that the load-bearing capacity of the underground engineering project plate meets the installation requirements of the construction elevator and prevent the elevator from causing damage to the roof during installation and use. If the load-bearing capacity of the underground engineering roof cannot meet the load-bearing requirements When doing so, it is necessary to design and formulate a foundation reinforcement plan to improve the load-bearing capacity of the top plate by installing steel structure supports under the roof and performing structural reinforcement.
3. Guide rail frame
When the angle between the wall-attached brace and the attachment surface is too large, a movable hinge is formed between the wall-attached brace and the guide rail frame. At this point, the wall-attached device loses its effective fixing effect on the guide rail frame. When the construction elevator is working, due to the influence of the weight of the cage, the guide rail frame will undergo partial changes along the force direction, which will often affect the guide rail frame. stability and accelerates the wear of guides and transmission devices, thereby shortening the service life of the equipment.
Usually the following methods can be used to solve this kind of problem: First, before installation, formulate a wall-attached plan according to the floor elevation of the building and the section height of the guide rail frame, so as to make the plane of the wall-attached support rod consistent with the section height of the guide rail frame as much as possible. The angle of the attachment surface is controlled within the standard range. If some wall-attached braces cannot meet the requirements, this can be solved by appropriately adding wall-attached devices; secondly, if combined with the wall-attached solution, there are still many wall-attached braces with planes that are in line with the requirements. The angle between the attachment surfaces is too large. Since the wall-attached struts can be installed at any position with indirect wall attachment, the installation method of indirect wall attachment should be used to solve the problem.