Existing tower crane safety risks and countermeasures

Tower crane is one of the leading construction machinery industry and civil construction in process of construction. It is due to the large radius of gyration, from lowering high simple operation, widely used in construction, to bring greater benefits to builders in construction technology, quality and progress on. But at the same time, due to the poor management and can not keep up regular maintenance different degrees, the operator and other reasons, the construction will give a serious security risk. Tower crane for construction projects use existing security common problem, proposed approach, we want to project safety management can play a positive role

1. Foundation
A common problem: serious water foundation.
Since the waste water project on the site of corrosive strong, after the water tower on the foundation, material and weld bolt, foundation or cross-section beam etching is strong, casual water, bound to affect the safety of the tower crane. At the same time, water is not conducive to the tower daily bolt, foundation section and the cross beam convergence bolt preload monitoring.
The right way: tower crane foundation should be set up gutters and water wells, while ensuring timely drainage dredge or extraction.
2. Specifications for convergence bolt preload
A common problem: Specifications for Cohesion loose bolts or preload is insufficient.
Tower crane force transmission times depend on the main chord to pass. The main chord force transmitted by the convergence of high strength bolt preload to complete. Mainly the preload force can only assume by the convergence bolt, tower crane consequences not only in the use of the process but also to bear the tensile shear accepted. The convergence of high-strength bolts shear to be poor, so that you can make the convergence bolt break, causing an accident down the tower.
The correct approach: the use of public torque wrench to tighten the bolts, making preload arrive requirements (such as M30 bolt preload 368kN, tightening torque 1800N m?). Daily carry out inspection, we found loose timely tightened. Here demand reminder: the use of high-strength bolts convergence Vice use again after assembly, generally not exceed twice. And respond bolt stop enjoying and reflection task, stops flaw detection, if necessary, qualified ahead may apply.
3. Ashamed pin of the pin set
A common problem: Set the pin is not ashamed standard minor are: 1) to tell whether the pin is too small, 2) pin ashamed not ashamed to tell whether or not enough, 3) welding with wire or pin replacement ashamed, 4) pin ashamed severe corrosion.
Because of the intensity or strength ashamed pin alternatives meet the requirements, ashamed pin in the axial force of the pin, pin ashamed often cut. Not ashamed enough to tell whether or ashamed of the pin in the use of the process is easy to fall, not ashamed pin pin will be in the use of self-detachment, which would cause a serious accident off the arm. If a site Jiayuan use of QTZ80 tower crane folding arm accident.
The correct approach: Set ashamed pin should be strictly according to the instructions to stop arming means, can not be replaced with a smaller size ashamed pin, wire or welding, also check corrosion levels and ashamed ashamed of is not opened before the pin means so as not to add difficulty and safety risks change after the device again. After the device pin requirements ashamed ashamed ashamed of bilateral and should reach 90 °.
4. Installation Safety Limit
A common problem: 1) safety limit is not installed role, 2) insensitivity to install safety limit, and 3) artificially shorted or removal.
Although not previously presented results, but the role of safety limit is not installed, buried a serious security risk. Temporary work overload, causing fatigue metal construction machinery and the life of the tower crane affected.
The right way: tower crane has been tested and its safety has been a fundamental limit installation commissioning qualified operators and other personnel can not arbitrarily stop removal and adjustment. At the same time each day to check on safety limit also be carefully examined.
5. Quality of operating personnel
A common problem: 1) the operator is not high quality, 2) operating without a license.
Since the operator is not high quality, strong sense of responsibility. Tower crane operation so frequent accidents.
The right way: special operations personnel to go through a special assessment, assessment of qualified job front may. At the same time to enhance the supervision of workers. Strictly follow the rules and work, no root certificate for employment.