With the development of social economy, the construction of high-rise and super high-rise buildings is increasing. As a tower crane for vertical transportation of building materials, it has become one of the necessary construction equipment on construction sites. Tower cranes have very high requirements for safety performance and are high-risk operations. Safety accidents caused by tower cranes are common in construction and the accident rate is very high. How to use tower cranes safely and efficiently is one of the urgent problems in the industry.
Repair and maintenance of metal structural parts
1. Strictly implement the scrap standard of crane steel structure.
2. The metal fatigue strength, weld cracks, structural deformation, damage, etc. should be checked for the main stressed structural parts. The key welds of the main stressed structural parts and the base metal of the welding heat affected zone should be checked. If found Exceptions should be dealt with. The inspection of structural parts should be carried out according to the following procedures.
(A) Daily inspection: A daily inspection should be carried out every 80 hours of operation of the tower crane. When the tower crane driver is handing over shifts, he should check the tightening of the bolts at each connection part, and tighten them in time if they are loose.
(B) When the tower crane makes abnormal noise, or has misoperation, or finds that the tower crane's safety protection device is out of order, it should be checked and recorded.
(C) When a project is completed and the tower crane is disassembled, detailed inspections should be carried out by engineers and professional maintenance personnel, and records should be kept.
3. Try to prevent structural deformation and collision damage during transportation.
4. Spray paint once every six months to a year. Before painting, remove rust spots, oil stains and other dirt on the metal surface.
Wire rope and its maintenance
1. During the use of the wire rope, the wire rope should be prevented from looping, kinking, bending or sticking to debris, and to prevent friction with machinery or other debris.
2. After the tower crane is installed (before use), the steel wire rope should be lubricated, and the steel wire rope should be lubricated once with graphite grease, and then the steel wire rope should be lubricated according to the "crane lubrication table".
3. The overall design of the tower crane does not allow the wire rope to have an indefinite life, and it should be scrapped under one of the following conditions:
a. Wire rope 6×19-d (d wire rope diameter) has more than 5 broken wires in 6d length, and more than 10 broken wires in 30d length.
b. Wire rope 6×37-d (d wire rope diameter) has more than 10 broken wires in 6d length, and more than 19 broken wires in 30d length.
c. The steel wire ropes are close together, even if the number of broken wires does not exceed 5 in the 6d length, they should be scrapped.
d. Although the wire rope has no broken wires, the wear of the wire rope reaches 40% of its diameter, or the wire rope is reduced by 7% or more from the nominal diameter, or the wire rope is obviously bent.
e. The wire rope loses its normal shape and produces deformities, such as waves, cage distortion, strand extrusion, steel wire extrusion, local increase in the rope diameter, kinks, local reduction in the rope diameter, and partial squashing and bending.
f. When the diameter of the wire rope is subjected to special heat, and there is an identifiable color on the outside.
Note: When lifting molten or hot metal, acid solution, *********, and flammable materials, the number of scrapped wire ropes will be halved. Conditions not mentioned in this manual shall be implemented according to GB5972.
At present, the common causes of tower crane accidents fall into the following three categories: 1. Design reasons; 2. Manufacturing reasons; 3. Use reasons. Among them, the reasons for use account for a large proportion, mainly due to the following factors: ⑴Illegal operation or misoperation (mostly in the process of disassembly and assembly); ⑵No or invalid safety protection device; ⑶Improper management and inadequate maintenance; ⑷ External environmental factors, such as typhoon, earthquake, etc.
Suggestions and countermeasures
1. Establish a complete tower crane management system, and establish a corresponding management system based on the actual situation of the enterprise.
⑴ Formulate relevant rules and regulations to standardize human behavior and machine conditions. In order to specifically regulate human behavior and the condition of the machine. Our company has formulated a series of rules and regulations: formulating tower crane safety operation regulations; tower crane maintenance regulations; operator training and certification system; establishing a strict "four inspection" system, namely installation, acceptance inspection, and operator handover Inspection, special inspection by site safety personnel and company safety inspection.
⑵Improve data management and establish one-machine one-file ledger. After the tower crane is purchased, a technical file is established for it, and it runs through the whole process of using the tower until the tower is scrapped. The previous installation, use, repair, maintenance, replacement of important parts, technical transformation, and safety accidents should be accurately recorded. All technical files are properly archived and kept. The main data saved are: tower crane production license, product qualification certificate, supervision inspection and verification, instruction manual, electrical schematic diagram, hydraulic system diagram, tower crane foundation diagram, previous installation and inspection reports, site survey data, tower crane disassembly and assembly Plans, safety technical disclosures, quality assurance documents for main parts (wire ropes, high-strength connecting bolts, anchor bolts and main electrical components, etc.), transfer records with the project department after previous installations, and maintenance records (including minor repairs, medium repairs, and overhauls) ) And signed by the responsible person.
2. Do a good job in disassembly and assembly management.
The disassembly and assembly of the tower crane is a prone stage of accidents. Safety accidents caused by improper disassembly and unqualified installation quality account for a large proportion. Therefore, disassembly and assembly management must be done.
⑴Technology center formulates a thorough disassembly and assembly construction plan. The disassembly and assembly plan is the criterion for disassembly and assembly operations, and strict implementation of the disassembly and assembly plan is an important guarantee for safe operations. The disassembly and assembly plan should include: buildings and operating environment, tower crane performance conditions and weight dimensions, disassembly and assembly methods and processes, safety technical measures, personnel arrangements and job responsibilities, disassembly and assembly equipment and tools, etc.
(2) Approval will be conducted after the technical center disassembly and assembly construction plan is formulated. After the disassembly and assembly construction plan is formulated, the technical center will submit the company’s leaders in charge of production safety, the chief engineer in charge of technology, the person in charge of the technical department, safety department, and equipment department to review and check the feasibility and safety of the plan. Conduct demonstrations and put forward audit opinions. Construction can only be carried out after passing the review.
(3) The Supervision Department does a good job in safety management and monitoring of disassembly and assembly operations.
①Inspect the tower crane to be disassembled and assembled before operation. According to the division of job responsibilities, each shall make a record of the inspection of its own project and sign the responsibility. The inspection items include whether each mechanism is working normally, whether each component is complete and effective, whether each electrical device and limit device are complete and effective. Disassembly and assembly operations can only be carried out if the tower crane is in good condition.
②Safety inspection of lifting equipment and sling equipment. Car cranes and attached sling equipment must be inspected to ensure that they are safe and reliable, complete in specifications, and meet operating requirements. The car crane should be in good condition, and both parties should confirm the equipment performance, rigging supplies, hoisting method, etc. before use.
③Inspection of the operating environment, before the operation, the project department and the truck crane shall jointly conduct a review and inspection of the road, site, and environmental conditions, and the disassembly and assembly operations can be carried out after confirming that the safe operation conditions are met.
④ Hold a safety briefing meeting before the disassembly and assembly operations, and the operation commander will explain the contents of the disassembly and assembly plan to all operators, propose safety technical measures, and strengthen the requirements for safe operations.
⑤ Do a good job monitoring, clarify the personnel and responsibilities of each post, be familiar with key operating points, safety supervisors will supervise on-site, deal with related issues, prevent illegal commands, and conduct safety management throughout the process.
⑷ Do a good job of acceptance. After the tower crane installation (lifting, wall attachment) is completed, the inspection department will conduct safety and quality acceptance, fill in the acceptance report, and rectify the unqualified requirements, and use it only after it is qualified.
3. Strengthen safety education and skill training for operators.
The key to tower crane management is the management of operators. The operator must be in good health, understand the mechanical structure and working principle, be familiar with the mechanical principle and maintenance rules, and hold a certificate. The driver must maintain the crane in accordance with the regulations, have a high sense of responsibility, and do the cleaning, lubrication, fastening, adjustment, and anti-corrosion work carefully. No work after drinking, no sick or fatigue work, and strictly follow the tower crane machinery operation Regulations and operation of tower cranes with "ten are not allowed, ten are not hoisted" shall not be illegal or barbarous, and shall have the right to refuse illegal commands, and adequate lighting shall be provided for night operations. The key to the safe use of the tower crane is the technical level and sense of responsibility of the operators, and the key to inspection and maintenance is the mechanical and electrical maintenance workers. We must firmly establish a people-oriented thinking, strengthen safety education and skill training for operators, and reduce the incidence of accidents.
4. Introduce advanced technology.
Apply the microcomputer processing system to the safety device and monitoring system. Judging from the current situation of tower cranes, most of the safety protection devices are still at a relatively low level, with low sensitivity, poor reliability and adaptability, high failure rate, and single function, especially the lack of self-detection and display functions, which are in line with foreign advanced levels. It's a far cry. At present, the tower crane is developing towards large-scale, automated, and multifunctional. It is imperative to introduce a real-time state process monitoring system to accurately measure and display various parameters during tower crane operation and realize multi-functional safety protection.
By strengthening the safety management of the above aspects of the tower crane, it can effectively prevent the occurrence of various accidents during the use of the tower crane, and play a role in preventing problems before they occur. Safe use and maintenance of tower cranes in high-rise building construction
With the development of social economy, the construction of high-rise and super high-rise buildings is increasing. As a tower crane for vertical transportation of building materials, it has become one of the necessary construction equipment on construction sites. Tower cranes have very high requirements for safety performance, which are high-risk operations. Safety accidents caused by tower cranes are common in construction, and the accident rate is very high. How to use tower cranes safely and efficiently is one of the urgent problems in the industry.
Repair and maintenance of metal structural parts
1. Strictly implement the scrap standard of crane steel structure.
2. The metal fatigue strength, weld cracks, structural deformation, damage, etc. should be checked for the main stressed structural parts. The key welds of the main stressed structural parts and the base metal of the welding heat affected zone should be checked. If found Exceptions should be dealt with. The inspection of structural parts should be carried out according to the following procedures.
(A) Daily inspection: A daily inspection should be carried out every 80 hours of operation of the tower crane. When the tower crane driver is handing over shifts, he should check the tightening of the bolts at each connection part, and tighten them in time if they are loose.
(B) When the tower crane makes abnormal noise, or has misoperation, or finds that the tower crane's safety protection device is out of order, it should be checked and recorded.
(C) When a project is completed and the tower crane is disassembled, detailed inspections should be carried out by engineers and professional maintenance personnel, and records should be kept.
3. Try to prevent structural deformation and collision damage during transportation.
4. Spray paint once every six months to a year. Before painting, remove rust spots, oil stains and other dirt on the metal surface.
Wire rope and its maintenance
1. During the use of the wire rope, the wire rope should be prevented from looping, kinking, bending or sticking to debris, and to prevent friction with machinery or other debris.
2. After the tower crane is installed (before use), the steel wire rope should be lubricated, and the steel wire rope should be lubricated once with graphite grease, and then the steel wire rope should be lubricated according to the "crane lubrication table".
3. The overall design of the tower crane does not allow the wire rope to have an indefinite life, and it should be scrapped under one of the following conditions:
a. Wire rope 6×19-d (d wire rope diameter) has more than 5 broken wires in 6d length, and more than 10 broken wires in 30d length.
b. Wire rope 6×37-d (d wire rope diameter) has more than 10 broken wires in 6d length, and more than 19 broken wires in 30d length.
c. The steel wire ropes are close together, even if the number of broken wires does not exceed 5 in the 6d length, they should be scrapped.
d. Although the wire rope has no broken wires, the wear of the wire rope reaches 40% of its diameter, or the wire rope is reduced by 7% or more from the nominal diameter, or the wire rope is obviously bent.
e. The wire rope loses its normal shape and produces deformities, such as waves, cage distortion, strand extrusion, steel wire extrusion, local increase in the rope diameter, kinks, local reduction in the rope diameter, and partial squashing and bending.
f. When the diameter of the wire rope is subjected to special heat, and there is an identifiable color on the outside.
Note: When lifting molten or hot metal, acid solution, *********, and flammable materials, the number of scrapped wire ropes will be halved. Conditions not mentioned in this manual shall be implemented according to GB5972.
At present, the common causes of tower crane accidents fall into the following three categories: 1. Design reasons; 2. Manufacturing reasons; 3. Use reasons. Among them, the reasons for use account for a large proportion, mainly due to the following factors: ⑴Illegal operation or misoperation (mostly in the process of disassembly and assembly); ⑵No or invalid safety protection device; ⑶Improper management and inadequate maintenance; ⑷ External environmental factors, such as typhoon, earthquake, etc.
Repair and maintenance of metal structural parts
1. Strictly implement the scrap standard of crane steel structure.
2. The metal fatigue strength, weld cracks, structural deformation, damage, etc. should be checked for the main stressed structural parts. The key welds of the main stressed structural parts and the base metal of the welding heat affected zone should be checked. If found Exceptions should be dealt with. The inspection of structural parts should be carried out according to the following procedures.
(A) Daily inspection: A daily inspection should be carried out every 80 hours of operation of the tower crane. When the tower crane driver is handing over shifts, he should check the tightening of the bolts at each connection part, and tighten them in time if they are loose.
(B) When the tower crane makes abnormal noise, or has misoperation, or finds that the tower crane's safety protection device is out of order, it should be checked and recorded.
(C) When a project is completed and the tower crane is disassembled, detailed inspections should be carried out by engineers and professional maintenance personnel, and records should be kept.
3. Try to prevent structural deformation and collision damage during transportation.
4. Spray paint once every six months to a year. Before painting, remove rust spots, oil stains and other dirt on the metal surface.
Wire rope and its maintenance
1. During the use of the wire rope, the wire rope should be prevented from looping, kinking, bending or sticking to debris, and to prevent friction with machinery or other debris.
2. After the tower crane is installed (before use), the steel wire rope should be lubricated, and the steel wire rope should be lubricated once with graphite grease, and then the steel wire rope should be lubricated according to the "crane lubrication table".
3. The overall design of the tower crane does not allow the wire rope to have an indefinite life, and it should be scrapped under one of the following conditions:
a. Wire rope 6×19-d (d wire rope diameter) has more than 5 broken wires in 6d length, and more than 10 broken wires in 30d length.
b. Wire rope 6×37-d (d wire rope diameter) has more than 10 broken wires in 6d length, and more than 19 broken wires in 30d length.
c. The steel wire ropes are close together, even if the number of broken wires does not exceed 5 in the 6d length, they should be scrapped.
d. Although the wire rope has no broken wires, the wear of the wire rope reaches 40% of its diameter, or the wire rope is reduced by 7% or more from the nominal diameter, or the wire rope is obviously bent.
e. The wire rope loses its normal shape and produces deformities, such as waves, cage distortion, strand extrusion, steel wire extrusion, local increase in the rope diameter, kinks, local reduction in the rope diameter, and partial squashing and bending.
f. When the diameter of the wire rope is subjected to special heat, and there is an identifiable color on the outside.
Note: When lifting molten or hot metal, acid solution, *********, and flammable materials, the number of scrapped wire ropes will be halved. Conditions not mentioned in this manual shall be implemented according to GB5972.
At present, the common causes of tower crane accidents fall into the following three categories: 1. Design reasons; 2. Manufacturing reasons; 3. Use reasons. Among them, the reasons for use account for a large proportion, mainly due to the following factors: ⑴Illegal operation or misoperation (mostly in the process of disassembly and assembly); ⑵No or invalid safety protection device; ⑶Improper management and inadequate maintenance; ⑷ External environmental factors, such as typhoon, earthquake, etc.
Suggestions and countermeasures
1. Establish a complete tower crane management system, and establish a corresponding management system based on the actual situation of the enterprise.
⑴ Formulate relevant rules and regulations to standardize human behavior and machine conditions. In order to specifically regulate human behavior and the condition of the machine. Our company has formulated a series of rules and regulations: formulating tower crane safety operation regulations; tower crane maintenance regulations; operator training and certification system; establishing a strict "four inspection" system, namely installation, acceptance inspection, and operator handover Inspection, special inspection by site safety personnel and company safety inspection.
⑵Improve data management and establish one-machine one-file ledger. After the tower crane is purchased, a technical file is established for it, and it runs through the whole process of using the tower until the tower is scrapped. The previous installation, use, repair, maintenance, replacement of important parts, technical transformation, and safety accidents should be accurately recorded. All technical files are properly archived and kept. The main data saved are: tower crane production license, product qualification certificate, supervision inspection and verification, instruction manual, electrical schematic diagram, hydraulic system diagram, tower crane foundation diagram, previous installation and inspection reports, site survey data, tower crane disassembly and assembly Plans, safety technical disclosures, quality assurance documents for main parts (wire ropes, high-strength connecting bolts, anchor bolts and main electrical components, etc.), transfer records with the project department after previous installations, and maintenance records (including minor repairs, medium repairs, and overhauls) ) And signed by the responsible person.
2. Do a good job in disassembly and assembly management.
The disassembly and assembly of the tower crane is a prone stage of accidents. Safety accidents caused by improper disassembly and unqualified installation quality account for a large proportion. Therefore, disassembly and assembly management must be done.
⑴Technology center formulates a thorough disassembly and assembly construction plan. The disassembly and assembly plan is the criterion for disassembly and assembly operations, and strict implementation of the disassembly and assembly plan is an important guarantee for safe operations. The disassembly and assembly plan should include: buildings and operating environment, tower crane performance conditions and weight dimensions, disassembly and assembly methods and processes, safety technical measures, personnel arrangements and job responsibilities, disassembly and assembly equipment and tools, etc.
(2) Approval will be conducted after the technical center disassembly and assembly construction plan is formulated. After the disassembly and assembly construction plan is formulated, the technical center will submit the company’s leaders in charge of production safety, the chief engineer in charge of technology, the person in charge of the technical department, safety department, and equipment department to review and check the feasibility and safety of the plan. Conduct demonstrations and put forward audit opinions. Construction can only be carried out after passing the review.
(3) The Supervision Department does a good job in safety management and monitoring of disassembly and assembly operations.
①Inspect the tower crane to be disassembled and assembled before operation. According to the division of job responsibilities, each shall make a record of the inspection of its own project and sign the responsibility. The inspection items include whether each mechanism is working normally, whether each component is complete and effective, whether each electrical device and limit device are complete and effective. Disassembly and assembly operations can only be carried out if the tower crane is in good condition.
②Safety inspection of lifting equipment and sling equipment. Car cranes and attached sling equipment must be inspected to ensure that they are safe and reliable, complete in specifications, and meet operating requirements. The car crane should be in good condition, and both parties should confirm the equipment performance, rigging supplies, hoisting method, etc. before use.
③Inspection of the operating environment, before the operation, the project department and the truck crane shall jointly conduct a review and inspection of the road, site, and environmental conditions, and the disassembly and assembly operations can be carried out after confirming that the safe operation conditions are met.
④ Hold a safety briefing meeting before the disassembly and assembly operations, and the operation commander will explain the contents of the disassembly and assembly plan to all operators, propose safety technical measures, and strengthen the requirements for safe operations.
⑤ Do a good job monitoring, clarify the personnel and responsibilities of each post, be familiar with key operating points, safety supervisors will supervise on-site, deal with related issues, prevent illegal commands, and conduct safety management throughout the process.
⑷ Do a good job of acceptance. After the tower crane installation (lifting, wall attachment) is completed, the inspection department will conduct safety and quality acceptance, fill in the acceptance report, and rectify the unqualified requirements, and use it only after it is qualified.
3. Strengthen safety education and skill training for operators.
The key to tower crane management is the management of operators. The operator must be in good health, understand the mechanical structure and working principle, be familiar with the mechanical principle and maintenance rules, and hold a certificate. The driver must maintain the crane in accordance with the regulations, have a high sense of responsibility, and do the cleaning, lubrication, fastening, adjustment, and anti-corrosion work carefully. No work after drinking, no sick or fatigue work, and strictly follow the tower crane machinery operation Regulations and operation of tower cranes with "ten are not allowed, ten are not hoisted" shall not be illegal or barbarous, and shall have the right to refuse illegal commands, and adequate lighting shall be provided for night operations. The key to the safe use of the tower crane is the technical level and sense of responsibility of the operators, and the key to inspection and maintenance is the mechanical and electrical maintenance workers. We must firmly establish a people-oriented thinking, strengthen safety education and skill training for operators, and reduce the incidence of accidents.
4. Introduce advanced technology.
Apply the microcomputer processing system to the safety device and monitoring system. Judging from the current situation of tower cranes, most of the safety protection devices are still at a relatively low level, with low sensitivity, poor reliability and adaptability, high failure rate, and single function, especially the lack of self-detection and display functions, which are in line with foreign advanced levels. It's a far cry. At present, the tower crane is developing towards large-scale, automated, and multifunctional. It is imperative to introduce a real-time state process monitoring system to accurately measure and display various parameters during tower crane operation and realize multi-functional safety protection.
By strengthening the safety management of the above aspects of the tower crane, it can effectively prevent the occurrence of various accidents during the use of the tower crane, and play a role in preventing problems before they occur. Safe use and maintenance of tower cranes in high-rise building construction
With the development of social economy, the construction of high-rise and super high-rise buildings is increasing. As a tower crane for vertical transportation of building materials, it has become one of the necessary construction equipment on construction sites. Tower cranes have very high requirements for safety performance, which are high-risk operations. Safety accidents caused by tower cranes are common in construction, and the accident rate is very high. How to use tower cranes safely and efficiently is one of the urgent problems in the industry.
Repair and maintenance of metal structural parts
1. Strictly implement the scrap standard of crane steel structure.
2. The metal fatigue strength, weld cracks, structural deformation, damage, etc. should be checked for the main stressed structural parts. The key welds of the main stressed structural parts and the base metal of the welding heat affected zone should be checked. If found Exceptions should be dealt with. The inspection of structural parts should be carried out according to the following procedures.
(A) Daily inspection: A daily inspection should be carried out every 80 hours of operation of the tower crane. When the tower crane driver is handing over shifts, he should check the tightening of the bolts at each connection part, and tighten them in time if they are loose.
(B) When the tower crane makes abnormal noise, or has misoperation, or finds that the tower crane's safety protection device is out of order, it should be checked and recorded.
(C) When a project is completed and the tower crane is disassembled, detailed inspections should be carried out by engineers and professional maintenance personnel, and records should be kept.
3. Try to prevent structural deformation and collision damage during transportation.
4. Spray paint once every six months to a year. Before painting, remove rust spots, oil stains and other dirt on the metal surface.
Wire rope and its maintenance
1. During the use of the wire rope, the wire rope should be prevented from looping, kinking, bending or sticking to debris, and to prevent friction with machinery or other debris.
2. After the tower crane is installed (before use), the steel wire rope should be lubricated, and the steel wire rope should be lubricated once with graphite grease, and then the steel wire rope should be lubricated according to the "crane lubrication table".
3. The overall design of the tower crane does not allow the wire rope to have an indefinite life, and it should be scrapped under one of the following conditions:
a. Wire rope 6×19-d (d wire rope diameter) has more than 5 broken wires in 6d length, and more than 10 broken wires in 30d length.
b. Wire rope 6×37-d (d wire rope diameter) has more than 10 broken wires in 6d length, and more than 19 broken wires in 30d length.
c. The steel wire ropes are close together, even if the number of broken wires does not exceed 5 in the 6d length, they should be scrapped.
d. Although the wire rope has no broken wires, the wear of the wire rope reaches 40% of its diameter, or the wire rope is reduced by 7% or more from the nominal diameter, or the wire rope is obviously bent.
e. The wire rope loses its normal shape and produces deformities, such as waves, cage distortion, strand extrusion, steel wire extrusion, local increase in the rope diameter, kinks, local reduction in the rope diameter, and partial squashing and bending.
f. When the diameter of the wire rope is subjected to special heat, and there is an identifiable color on the outside.
Note: When lifting molten or hot metal, acid solution, *********, and flammable materials, the number of scrapped wire ropes will be halved. Conditions not mentioned in this manual shall be implemented according to GB5972.
At present, the common causes of tower crane accidents fall into the following three categories: 1. Design reasons; 2. Manufacturing reasons; 3. Use reasons. Among them, the reasons for use account for a large proportion, mainly due to the following factors: ⑴Illegal operation or misoperation (mostly in the process of disassembly and assembly); ⑵No or invalid safety protection device; ⑶Improper management and inadequate maintenance; ⑷ External environmental factors, such as typhoon, earthquake, etc.
