Common safety hazards in construction machinery construction
Source: | Author:lichengcn | Publish time: 2017-08-24 | 4 Views | Share:
      In order to strengthen the safety management of construction site, a series of safety management documents have been issued in recent years.On the construction site of the pile driver, material hoist, tower crane and construction hoist safety performance examination and repair, inspection, construction machinery has exposed many problems of safe hidden trouble.Through the regulation management, the effect is very obvious, the local construction department generally feels that such safety performance check is very necessary, can reduce the security accident in the region greatly.
      In order to make our province of the construction safety management make better, further reducing safety accidents caused by construction machinery and construction machinery, construction machinery in these two years we summed up all over the province construction site testing safety accidents problem found during the inspection, it is necessary.
1. Safety hazards caused by electrical installation
      (1) the construction site distribution box, equipment electric control box without leakage protection or leakage protection.
      At present, the construction site requires three-phase five-wire power supply, with three-pole distribution protection.Because of this, there are very few electrical accidents in the construction site.But in the on-site inspection, found that some have appeared on the construction site safety hidden danger, the electric leakage protector in the primary distribution box is installed, and reliable work, however, some in the secondary or tertiary distribution box is the leakage protector, are some of the leakage protector failure, once in the primary distribution box leakage problems, safety accident is hard to avoid.Special to some important construction machinery, according to relevant standards and specification requirements, must be equipped with leakage protection device or separate distribution box, for example, piling machine, tower machine, etc.Site operators tend to think that the construction machinery can be used to set up a single leakage protector, which is often omitted and directly from the primary distribution box.In fact, everyone knows that more than one leak protector, more security, must not save the cost.In addition, the leakage protection device is installed on the construction machinery electric control box. The operator can always conduct the test inspection before operation to ensure its reliable work.
      (2) the enclosure of the device is not grounded or grounded.
      The construction site adopts three-phase five first power supply, the grounding line is required to connect with the electric control box of the construction machinery, and the connection is reliable.This is because when the insulation of the electric control system of a certain phase damage and into the shell, electric shell due to the ground, will form the single phase short circuit, make the electric protection device, thus make charged shell will no longer be charged, achieve the goal of security.Secondly, in the case of the leakage protection device failure, this shell grounding device can be used to turn off the air switch and cut off the power supply when the shell is charged.On-site inspection and inspection found that the grounding line of the four core cable or five-core cable was still not grounded in the construction site, leaving a safety hazard.
      (3) the electric control box is used in the distribution box, and the box is cluttered with wiring.
      This situation is found in the safety performance inspection of pile driver.Especially in some self-control on the driver of this kind of electric control of driver to complete the driver itself in all kinds of operation tasks, but also to undertake the driver outside of the electrical equipment electrical box functions, such as electric welding machine, water pump, construction site near the lighting, all from inside the electrical cabinet, wiring chaotic, the leakage protector can't protect inside the electric cabinet, easy to cause accident getting an electric shock.
2. Safety hazards caused by mechanical installation
      In the field construction machinery safety performance inspection, this aspect of the problem is relatively few, mainly occurred in the piling machine.Due to the long working time, high frequency and poor working environment, the maintenance and installation quality of the equipment is very important, which is the key to the safety hazard.Through inspection, the following problems are mainly found:
      (1) the connection pins of the posts, inclined supports or pulleys of some pile machines are not locked;
      (2) the connecting bolt of the pillar base of some piles and the chassis of the pile machine has been badly maintained for years, and has been corroded (some bolts are lightly tapped with a hammer, and the bolt is broken);
      (3) bolt flange connecting bolt lacks maintenance and rust.The number of bolts that should be used when the flange connection is not fully used, resulting in a decrease in connection strength;
      (4) some key welding (such as welding of pillar base and pile chassis), because of the long and frequent use, which caused the dissoldering and cracking, and not found and repaired the reinforcement in time.
      (5) the wire rope used for lifting weights is quite serious and is still in use.
3. Safety hazards caused by installation and commissioning
      Installation and debugging problems mainly occurred in some electromechanical conversion device was used as safety device of construction machinery, the electromechanical conversion device is used to control various environmental parameters, such as: wind, gravity, pressure, location, travel, temperature, etc, like a tower crane, material hoist, have some of this device.These devices need to be debugged or adjusted before construction.On the tower crane hook upward limit position, the car inside and outside of the forming limit position, torque limiter setting, etc., are to be adjusted before use and debugging, the device to adjust or not is not only related to tower crane can be normal use, but more importantly to the safe use of tower crane.The following problems are frequently encountered during on-site inspection:
      (1) the moment limit of the tower is not adjusted or adjusted excessively;
      (2) the control switch of the changing speed at 80% of the maximum moment of the tower is not adjusted or adjusted excessively;
      (3) there is no adjustment to the limit position of the tower vehicle when moving inward;
      (4) no installation of the moving switch of the material lift door;
      (5) the material lifting mechanism fails.
4. Conclusion
      These problems are very serious security problems, which are caused by the lack of attention of the construction unit and the result of paralysis.On the other hand, it is also caused by the relaxation management of site safety management personnel on site and site.In order to ensure the safety of the construction site construction, in the hope that the local site safety management and site personnel to identify the current form of security, to further strengthen safety management of the construction site, seriously, carefully check, the timely processing of all kinds of potential safety hazard, truly nip in the bud.We also hope that our inspection and inspection can provide some help for the construction safety management in all areas of our province.