Construction status of the hottest tower crane and

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The current situation of tower crane construction and the significance of using safety monitoring and management devices for tower cranes

at present, tower cranes are important equipment for lifting and transportation operations in construction projects. Tower crane accidents are related to the national economy and the people's livelihood and pose great hazards. At present, although many tower crane drivers have work licenses, due to the lack of supervision and review means, they have serious violations in actual work. It is very important to strengthen inspection and assessment. The causes of tower crane overturning accident can be divided into two aspects: on the one hand, because the management of tower crane is not in place, illegal operation, illegal overload, cable-stayed and inclined crane are common; Second, the potential safety hazards of the tower crane can not be found in time. For example, when the tower crane foundation is tilted, the key welds have microcracks, and the bolts are loose, the potential defects are further worsened during the continuous use of the tower crane, resulting in the overturning of the tower crane. The reasons for the current situation are discussed below, and the significance of using the safety monitoring and management system is analyzed

I. cause analysis

1. Subjective cause:

80 ~ 100hrh

considering its construction speed, the user of tower crane always wants to hoist all the materials that need to be hoisted in the shortest time. Therefore, under the condition of a certain number of hoists, it wants to achieve the above purpose by increasing the weight of each hoist. Subjectively, the biggest advantage of electronic data testing machine is that it greatly improves the measurement accuracy, and there is a serious tendency of overload

in order to maintain the continuous growth of customers and the continuous expansion of leasing business, some tower crane leasing units turn a blind eye to the overloading and other illegal operations of the user units, and even individual business personnel rent low specification tower cranes as high specification tower cranes in order to earn the lease price difference. Even if the user units lift according to the tonnage of the lease agreement, the tower crane itself has been overloaded, It has indulged overload and other illegal operations, so whether the leasing unit or the user unit is driven by interests, it subjectively resists effective supervision

2. Objective reasons:

the original safety limit of tower crane uses the edible, water-soluble and other characteristics of some plastic packaging materials. Due to the lack of weights on site, it cannot be adjusted in time, resulting in the safety limit becoming a decoration. When the driver of tower crane finds danger, it is easy to have emergency stop and emergency return

the technical archives of tower cranes, especially the cumulative operation records, are mostly filled out by the using or leasing units, and the management department is unable to verify their authenticity, which creates an opportunity for illegal operations

due to the above reasons, the tower crane is generally overloaded and other illegal operations in the use process. In addition to itself, it is very easy to cause safety accidents, frequent overloading is likely to cause fatigue damage to some parts of the tower crane steel structure, especially the sudden rise and fall under overload, which will cause huge damage to the tower crane structure and is very easy to form a bad accident

II. Significance analysis of using the safety monitoring and management device of tower crane

at present, the safety monitoring devices that have been developed and used include black box and anti overturn monitor, in which the monitor records and alarms by observing the tilt of tower crane, whether it is the working state of tower crane (such as overload, oblique tension, etc.), or non working state (such as loose bolts, uneven foundation sinking), The inclination of the tower crane can be recorded and alarmed if it exceeds the critical state

1. Use the safety monitoring and management device of tower cranes to obtain real first-hand data through high-tech means (such as recording chips), which cannot be changed manually. In order to truly implement the regulations on the administration of safe production of construction projects (order 393 of the State Council), the measures for the filing and registration of construction hoisting machinery (JZ [2008] No. 76), the regulations on the safety supervision of special equipment (order 373 of the State Council) Provide strong technical support for the relevant requirements of the regulations on the safety supervision and management of construction cranes (Order No. 166 of the Ministry of construction), technical conditions for tower cranes gb/t, safety regulations for tower cranes GB, and regulations for the operation and use of tower cranes jb/t

2. The use of tower crane safety monitoring and management device is the need to strengthen supervision and management and eliminate potential accidents. Installing the tower crane safety monitoring and management device can effectively reduce violations. First, the gray areas that tower crane managers have been used to will be transparent after data processing; Secondly, the unskilled or even unqualified operator PPC has finally achieved the skill evaluation of mass production personnel, which will be exposed through data statistics; Finally, all the data of the tower crane use process (including the lifting state and non lifting state) will be reproduced through data analysis, so that relevant personnel are accustomed to the supervised working state; In the past, it was the opposite (that is, the work of almost all relevant personnel, including the maintenance, use and disassembly of drivers, disassemblers and commanders (signal workers), was not supervised)

some managers mistakenly believe that the safety of the tower crane can be guaranteed as long as the current safety limiter is used normally. In fact, the safety of non overload state and all operation records cannot be achieved through the current safety limiter

3. Using the safety monitoring and management device of tower crane is the need to cultivate the team, improve the quality of employees and improve the technical level of supervision and management. By punishing the driver for wrong behaviors such as hitting the wrong car, stopping and lifting in an emergency, and pulling and lifting in an oblique way, and educating the driver and the manager, the probability of malignant accidents will be effectively eliminated. Especially when the tower crane driver cannot observe the lifted weight, if the commander does not limit the state (weight, position) of the goods assembled by the workers, the driver can know whether the lifted weight is overloaded or inclined through the monitor during lifting, and take measures to correct it in time

for tower cranes, sometimes the connection pin hole and pin fit do not meet the design requirements, and the connection high-strength bolts are not tightened in time after loosening. Through timely maintenance and remedial measures, the safe and reliable construction progress of the construction project can be guaranteed

through the driver's observation of the inclination of the tower body indicated by the instrument and the monthly data statistics and sorting, it can ensure that the lateral perpendicularity of the axis line of the tower body meets the requirements, reduce the number of measurements of the lateral perpendicularity of the axis line of the tower body, and it is not necessary to use theodolites and professionals to complete the measurement of the lateral perpendicularity of the axis line of the tower body every time, which simplifies the management links and improves the management level

the data recording function of the safety monitoring and management device ensures the scientific identification of accidents, improves the management data recording, provides basic data for tower crane life prediction and tower crane steel structure integrity diagnosis, and provides the possibility for scientific management and active accident prevention, which can easily and truly meet the current national relevant industry regulations

III. conclusion

the use of tower crane safety monitoring equipment (anti overturn monitor and tower crane black box) on the one hand, because it accurately and truly records its operation, provides the basis for the supervision department to strengthen management and strictly enforce the law. Then urge operators and commanders to improve safety awareness and reduce or eliminate potential safety accidents. On the other hand, its timely alarm function should be able to timely remind operators to prevent sudden safety hazards. The only disadvantage is the need to increase some investment, but it is very worthwhile compared with the security of the people

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