How to conduct safety protection during steel structure construction?

Analysis of the particularity of the working environment and working conditions of the welders in the construction site of the building steel structure

1. Copper structure building type and installation process

Steel structure buildings can be divided into five categories: light steel structure (including portal steel frame), heavy steel structure, high-rise steel structure, spatial steel structure (including grid frame, grid shell and space truss) and residential steel structure. It includes two processes: factory fabrication and on-site installation. Steel structure construction is the process of hoisting and assembling the fabricated components to the predetermined position in the design according to a certain order, then measuring, correcting, connecting and fixing, integrating piece by piece and unit by unit, and finally forming a structural system. The installation process method is determined on the site according to the type of steel structure project. Manual arc welding is commonly used for welding at the construction site. Under special circumstances, argon tungsten arc welding and carbon dioxide gas welding are used. Cutting method: oxyacetylene flame cutting, grinding machine cutting.

2. Construction project management

The project manager responsibility system is implemented for the construction of steel structure projects. The quality and management level of the project department personnel are quite different. There is a general management situation that attaches importance to progress, quality and safety.

3. Working environment of welders at the construction site

The structural characteristics and installation process methods of steel structure engineering determine the working environment of welders:

a. Working at heights.

b. Open air operation.

c. Cross construction of multiple types of work.

d. The operation space is limited and the operation is conducted in a multi obstacle environment.

e. The operation location is variable, and the site traffic is inconvenient.

f. The construction site is limited, and there are many materials and equipment temporarily stacked on the site.

g. High temperature, severe cold, rain, snow, fog, wind and other adverse meteorological environments.

h. An environment with dark light and low visibility at night.

i. Environment in contact with live conductors and metal components.

j. Contact with flammable and explosive materials.

k. Environment exposed to high temperature thermal radiation.

4. Working conditions of welders at the construction site

Compared with welders in other industries, welders in the steel structure construction site have more manual operations and less mechanization. The mobility of the construction site is high, the logistical support of the construction site is generally behind, the safety investment is insufficient, the labor protection articles are not issued in time, and the protective measures are not implemented in place. The working and living environment and sanitary conditions are relatively poor.

Analysis of hazard factors of welders in construction site of building steel structure

1. Electric shock. Welders have the highest probability of electric shock. Welders are easy to contact directly charged bodies such as welding tongs, welding rods, binding posts, high-voltage wires, and indirectly charged bodies such as cables with damaged insulation, welding machine shells with electric leakage, and charged metal structures. The welder’s PPE is defective or not worn, and his body sweats in summer. There are many node rods, small operation space, many obstacles, short circuit of grounding grid, failure of leakage protection device, and damage of insulation isolation of welding station. Electric shock accidents are easily caused by wet environment such as rain, snow and fog, insufficient lighting, construction personnel violating safety operation regulations, and switching on at will.

2. Hazards of falling from height. The climbing ladder and scaffold board are unstable; Failing to wear a safety belt or walking on the pole when welding at the working point; The safety belt is damaged; The safety belt is hung low and used high, and the hanging rod is unstable; No safety net is erected; Heatstroke, dizziness and standing too fast in high temperature environment; Welders step down and slip in snow, rain, wind and fog environment; When cutting the component, the component suddenly separates and the tension strikes the operator; Instability due to electric shock: welders work at heights with faults.

3. Object strike. The hazard factors are analyzed from two aspects. One of the welders was injured: there was no isolation protection at the cross operation site. Second, welders hurt people: tools and materials at the welder’s work point slipped, welders threw away wastes at will, cutting pieces separated, spot welding pieces were not firmly fixed, and structural parts fell.

4. Fire and explosion hazards. Flammable and explosive gasoline, paint, gas cylinders, and decoration materials are stored around or below the welding or cutting points at the cross operation site. The distance is not enough, isolation measures are not taken, monitoring measures are not taken, and fire-fighting facilities are not available. Sparks are found at the overlap of the welding return line at the storage point of flammable and explosive materials: personal protective equipment is stained with grease, and gas cutting tools such as gas leaking regulating valve, cutting gun, gas belt and gas cylinder are used. Fire and explosion accidents are caused by bad habits such as exposing cylinders to the sun under high temperature and purging work clothes with oxygen.

5. Hazards of electric arc burns. Close the power switch when the workpiece of the welding tongs is short circuited or open the power switch when the workpiece is in operation, and the switch is arcing, injuring hands. Welding operation without personal protective equipment, electric arc injury to hands, eyes or other exposed skin.

6. Burn hazard factors. Do not wear protective equipment when contacting welding seams, cutting seams or uncooled workpieces.

7. Heatstroke hazard factors. The welder sweats too much due to continuous welding in hot weather. Improper construction organization and arrangement, and blind progress. The heatstroke prevention measures are not in place.

8. All kinds of accidents and specific factors of welders at the construction site can be summarized as three major factors: people, materials and environment. Human factors include the welder himself, personnel of other types of work on the site, and management personnel. The unsafe behaviors of these three types of personnel will cause chaos on the construction site or directly endanger the welder. Material factors include equipment, tools, materials, components and protective equipment involved in welding operations. The unsafe state of these materials constitutes a hazard factor. Environmental factors mainly refer to the environment of such operation sites as high-altitude operation, cross operation, open-air operation, and harsh meteorological environment. The second is the soft environment of project management level. Disordered project management will directly lead to accidents and endanger welders.