What are the key points for safety control of bridge deck construction protection?

1. On-site temporary electricity safety control

A. Electrician requirements

1. Electricians must hold a certificate to work.

2. Temporary electrical equipment and wiring must be completed by an electrician and should be supervised.

3. Before using electrical equipment, you must wear and be equipped with corresponding labor protection equipment as required, and electrical devices and protective facilities should be inspected. It is strictly forbidden to operate equipment with "defects".

4. The switch box of temporarily disabled equipment must disconnect the power isolation switch and close the door and lock it. When moving electrical equipment, the electrician must cut off the power supply and handle it properly.

B. Distribution box and switch box

1. Implement three-level power distribution and two-pole protection;

2. Distribution box and switch box The distance should not exceed 30m. The horizontal distance between the switch box and the fixed electrical equipment it controls should not exceed 3m. Each electrical equipment must have its own dedicated switch box. It is strictly forbidden to use the same switch box to directly control one or more units. Electrical equipment (including sockets);

3. Distribution boxes and switch boxes should be installed in dry, ventilated and room temperature places. Ensure stability

4. The electrical installation board of the distribution box must be equipped with an N line terminal board and a PE line terminal board. The N line terminal board must be insulated from the metal electrical appliance mounting plate; the PE line terminal board must be electrically connected to the metal electrical appliance mounting plate. The N wire in the incoming and outgoing wires must be connected through the N wire terminal board, and the PE must be connected through the wire terminal board;

5. The shape and structure of the distribution box and switch box should be rainproof and dustproof;

C. Selection of electrical devices.

1. The electrical appliances in the distribution box and switch box must be reliable and intact. It is strictly prohibited to use damaged or unqualified electrical appliances.

2. The rated leakage action current of the leakage protector in the switch box should not be greater than 30mA, and the rated leakage action time should not be greater than 0.1s. Leakage protectors used in places with humid or corrosive media should use splash-proof products with rated leakage action. The current should not be greater than 15mA, and the rated leakage action time should not be greater than 0.1s;

3. The rated leakage action current of the leakage protector in the main distribution box should be greater than 30mA, and the rated leakage action time should be greater than 0.1s , but the product of its rated leakage action current and rated leakage action time should not be greater than 30mA.s.

4. It is strictly prohibited to use plugs and sockets for movable connections at the power incoming ends of distribution boxes and switch boxes

D. Cable lines

1. Cables All working cores and cores used as protective neutral conductors or protective earth conductors must be included.

2. The power distribution cable lines must use five-core cables. Five-core cables must contain insulated core wires of two colors: light blue and green/yellow. The light blue core wire must be used as the N wire; the green/yellow two-color core wire must be used as the PE wire, and mixing is strictly prohibited

3. The number of cable core wires should be based on the load and the number of phases and wires of the control appliances. The number is determined: when three-phase four-wire, five-core cable should be selected; when three-phase three-wire, four-core cable should be selected; when three-phase electrical equipment is equipped with single-phase electrical appliances, five-core cable should be selected; single-phase two-wire When using, three-core cable should be used. The main power distribution cabinet and distribution power box switch box must use five-core cables for power supply.

4. The on-site power lines are used overhead and need to be mopped for pipe protection and to prevent mechanical crushing.

E. Grounding

1. In the TN-S zero connection protection system for dedicated power supply at the bridge construction site, the metal shell of the electrical equipment must be connected to the protective neutral line.

2. All machinery and equipment on site must be well grounded and protected, and the grounding must be firm and reliable.

F. Use and maintenance

1. Distribution boxes and switch boxes should have names, uses, branch markings and system wiring diagrams. The doors of distribution boxes and switch boxes should be equipped with The lock should be locked by a dedicated person

2. During inspection and maintenance, you must wear insulating shoes and gloves as required, use electrical insulating tools, and keep records of inspection and maintenance work;

3. When performing regular maintenance and inspection on distribution boxes and switch boxes, the corresponding electrical isolation switch at the previous level must be opened and powered off, and a power outage signboard "No closing, no one working" must be hung. Live work;

4. Distribution boxes and switch boxes must be operated in the following order:

1) The order of power transmission operations is: main distribution box - distribution box - Switch box;

2) The sequence of power outage operations is: switch box - distribution box - main distribution box

5. Distribution boxes and switch boxes should be inspected and maintained regularly . Inspection and maintenance personnel must be professional electricians.

J. Electrical equipment used at the construction site must be protected by grounding, and dysprosium lamps, iodine-tungsten lamps, etc. used on site must be protected by grounding.

2. Construction Machinery

A. Straightening and Shearing Machine

The straightening and shearing machine can automatically straighten and cut the steel bars. Press the cutting mechanism The difference is divided into two types: down-cut scissors and rotary-cut scissors. The following matters should be paid attention to when operating:

1. Select the appropriate straightening block and transmission speed according to the diameter of the steel bar. When the straightening block is not fixed , Do not feed materials before the protective cover is covered;

2. Before feeding, the non-straight material head should be cut off. The machine should be stopped for threading the upper wire rod and cutting off the leader;

3. When straightening the short coiled steel bars, you should hold the casing and escort them to the guide to prevent accidents caused by the steel bars swinging and injuring people.

B. Cutting machine

There are manual cutting machines, electric cutting machines and hydraulic cutting machines. The following matters should be paid attention to when operating:

1. The steel bars must be Cut off after straightening. The steel bars should go straight into the knife edge and be perpendicular to the knife edge;

2. The diameter and strength of the steel bars specified on the machine nameplate must not be exceeded; when multiple steel bars are cut at one time, the total cross-section should be within the specified range;

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3. The distance between the hand and the cutter should be more than 15cm. When the length of the material is less than 40cm, the short steel bar head should be clamped firmly with a casing or clamp.

C. Bending machine

The bending machine can bend the cut, straightened and matched steel bars into the required shape. There are three types: manual, electric and hydraulic. Attention should be paid during operation:

1. The workbench and the bending machine table should be on the same level;

2. Install the mandrel according to the diameter and bending radius of the processed steel bar (the diameter of the mandrel Should be 2.5 times the diameter of the steel bar).

D. Woodworking Machinery

The common woodworking machinery at construction sites are mainly circular saws and plane planers (hand planers). These two machines are also the most likely to cause accidents among woodworking machinery. Lots of machinery.

1. Circular saw

(1) The saw blade must be flat and firm, with sharp teeth and a proper cutting path (otherwise, saw pinching is easy to occur), and the saw blade must not have continuous missing points. Do not use cracked saw blades.

(2) Safety protection devices must be complete. The thickness of the dividing knife should be moderate and the position should be appropriate so that the saw will not be pinched when sawing long materials; the position of the saw disc guard should be fixed above the saw disc and must not be rotated at will during use; a stop should be installed between the saw blades at the operator's position The net should be used to prevent the wood from rebounding and injuring people when it encounters knots and nails when breaking. The net should be rigid enough to prevent the wood from rebounding, and at the same time, it should not block the operator's line of sight to clearly see the ink lines of the sawn wood.

(3) There should be switch control (handle switches are not allowed to prevent accidental startup due to collision), and the distance between the gate boxes should not be greater than 2m, so that the power supply can be quickly cut off in the event of a failure.

(4) When cutting off wood and sawing short materials, use a push stick. Do not feed directly by hand, and the feeding speed cannot be too fast. The planing hook must be used to pick up materials. Sawing of short materials less than 50 cm long is prohibited.

2. Surface planing

(1) It should be clearly stipulated that, except for professional carpenters, other types of workers cannot operate it;

(2) A switch box should be installed , the distance between the switch box and the equipment is no more than 3m, so that the power can be cut off quickly when a fault occurs;

(3) Before use, it should be run idling, and the operation can only be carried out when the speed is normal and there is no fault.

When planing, you should hold the material with both hands and use tools when pressing the material. Do not press the material directly with your hands to prevent accidents caused by moving the wood and pressing it empty;

(4) Machinery is not allowed for wood shorter than 20cm . Timbers longer than 2m should be operated by two people;

(5) Before planing, the wood should be carefully inspected, and any iron nails, mortar, etc. should be removed first. When there are knots or stubble, The propulsion speed must be appropriately slowed down;

(6) Highly sensitive and reliable hand protection devices must be installed. At present, protective devices used in various places vary, but no matter what form they are, they must be sensitive and reliable, and have been proven by tests to be able to play a protective role.

(7) After the protective device is installed, a dedicated person must be responsible for its management and cannot be removed for various reasons. When a malfunction occurs, the machine cannot continue to be used. It must wait until the device has passed the maintenance test before it can be used again.

E. Water pump

1. The water pump must be used firmly and steadily, with good waterproofing and insulation.

2. Use the power cord and leakage protector correctly to ensure they are in good condition. Do a good job in protecting the connection of PE wires. If any abnormality occurs during on-site water pumping and maintenance, inspection must be carried out after power outage. There is a dedicated person on site to take care of the water pump.

F. Electric welding machine

1. Strictly follow the principle of "one machine, one gate, one drain, one box" to set up a separate switch for the electric welding machine, and make the casing of the electric welding machine It is best to connect to zero protection or ground protection.

2. The welding clamp and the handle wire must be well insulated and firmly connected. Wear gloves when replacing the welding rod. When working in wet locations, stand on insulating rubber sheets or wooden boards.

3. When changing venues and moving the handlebars, the power supply should be cut off, and climbing ladders cannot be held with the handlebars in hand.

4. At the end of the work, the power supply of the welding machine should be cut off, and the operating location should be inspected to confirm that there is no risk of fire before leaving.

5. The continuous copper plate must be pressed tightly, and the terminals should have washers. Before closing, check the connecting nuts, bolts and other parts in detail to ensure that they are not loose or damaged

J. Oxygen and acetylene management

1. Oxygen and acetylene bottles must not be placed in the same place, and the distance from flammable and explosive materials must not be less than 10m. It is strictly forbidden to use open flames to detect air leaks.

2. Oxygen and acetylene bottles should be placed in a cool place. They should be placed with care to prevent sparks or sharp objects from colliding with the hose. When oxygen cutting, the acetylene should be turned on first and the acetylene turned off first.

3. The surfaces of oxygen bottles, oxygen meters and welding and cutting tools are strictly prohibited from being stained with grease. Oxygen and acetylene bottles must not be placed directly under the wires.

4. Oxygen and acetylene bottles should be equipped with anti-shock rubber rings and safety helmets should be tightened to avoid collisions, violent vibrations and strong sunlight exposure.

5. The welding gun must not be pointed at anyone when igniting, and the burning welding gun must not be left randomly.

6. After welding is completed, the oxygen and acetylene bottle valves should be tightened, and the safety cover should be tightened.

H. Handheld power tools

1. Before using handheld power tools, check whether the shell, handle, plug, switch, leakage protector, and protective cover are intact and effective, and confirm In good condition before use.

2. Hold it firmly during operation, wear insulating gloves and insulating shoes, apply force evenly, and do not use excessive force to prevent damage to the drill bit or parts and injury to people.

3. When transporting, do not use cables to drag power tools to avoid breaking or wearing the cables and pulling off the plugs.

4. When replacing plugs and components, turn off the power first, unplug the plug, and confirm that there is no power before replacement. The operator should wear insulating shoes and insulating gloves when operating, and if necessary Glasses and used handheld power tools should be stored in a dry place to prevent moisture.

I. Vibrator

1. When using, please check the appearance of the vibrator to ensure that it is in good condition and that the power cord is well insulated.

2. Check during use to prevent dangers such as skin breakage, and perform maintenance after use. Use leakage protectors correctly.

3. Prestressed tensioning construction

1. During prestressing tensioning, unrelated personnel are not allowed to enter the tensioning operation area.

2. The tensioning equipment and tools should be cleaned and inspected before tensioning.

3. All interfaces between the high-pressure oil pump and the jack must be intact, and oil pump operators must wear protective glasses.

4. When the oil pump is started, the oil inlet and return speed and the rise and fall of the pressure gauge pointer should be smooth and consistent, and the safety valve should always remain sensitive and reliable.

5. Before tensioning, the operator must confirm the contact signal.

6. If any abnormality occurs during the tensioning operation, stop the machine immediately for inspection.

7. Before and after tensioning, both ends of the tensioning anchor should be properly protected. No heavy objects should be placed on them. It is strictly forbidden to hit the anchors, steel strands and steel bars.

8. When grouting pipelines, it is strictly forbidden to carry out the specified pressure. The safety valve should be adjusted before applying pressure. During grouting, personnel should wear protective glasses and workers should stand on both sides.

IV. Protection for high-altitude operations

1. Definition: Any operation at a height where there is a possibility of falling above 2m (including 2m) from the reference plane is called high-altitude operation. The working height is divided into four areas: 2~5m, 5~15, 15~30m and above 30m.

2. During the bridge construction of this project, high-altitude operations mainly include edge operations, opening operations, and independent suspended operations. Necessary safety protection technical measures must be taken for high-altitude operations.

3. All high-altitude operations must be coordinated and directed by dedicated personnel.

1), edge operations

At the construction site, when there are no containment facilities on the edge of the working surface, operations at heights where people and objects may fall in various ways are classified as Edge work.

1. The protection for bridge edge operations is mainly to set up protective railings and protective safety nets. The railings should be composed of upper and lower horizontal bars and railing posts. The height of the crossbar is stipulated to be 1.0~1.2m for the upper bar and 0.5~0.6m for the lower bar, that is, it is located in the middle.

2. Completely enclosed with green dense mesh safety net. If there is no external scaffolding, the outer perimeter of the bridge should be fully enclosed with a dense mesh safety net. If there is external scaffolding, the outside should also be fully enclosed with a dense mesh safety net.

3. Safety belts for edge workers must be used correctly and the fastening points must be secure.

2) Opening operations

1. During the bridge construction process, the wet joints of the bridge deck are the main protection for the openings, and bamboo fence protection, dense mesh safety nets or other fall protection are used facilities and set up safe passages.

2. To protect the wet joints of the bridge deck, the box girders should be protected wherever they are erected. Safety facilities should be removed every time they need to be used, and safety protection should be restored in a timely manner during construction.

3) Safety protection for suspended operations

1. At the construction site, when the surrounding area is in the air, the height is 2m or more, which is considered to be suspended work at high altitudes. The legal definition of suspended high-altitude operations is: "High-altitude operations carried out under the conditions of no foothold or no secure foothold are collectively referred to as suspended high-altitude operations." Therefore, suspended operations do not have a foothold and must be properly secured. Footholds, such as setting up operating platforms, scaffolding or hanging baskets, etc.

2. Safety protection facilities such as hanging baskets must be used for construction after being inspected and accepted by the construction personnel.

3. Construction workers working at suspended heights must correctly use safety belts, safety ropes, and safety protective equipment. Safety protective equipment must be inspected before each shift and used after passing the inspection.

4. Special personnel must be on duty at the suspended high-altitude work site, report any hidden dangers in a timely manner, and promptly resolve safety hazards before proceeding with construction.

5. Workers working at suspended heights must pay attention to safety protection when hoisting formwork and other materials.

4) Safety protection for cross operations

1. When performing cross operations, the lower working position must not be operated up and down in the same vertical direction at the same time, and must be in a position where the possible fall is determined based on the height of the upper layer. Half outside the range. If this condition is not met, a safety protection layer should be installed in the middle.

2. When the upper part must lower materials and machinery downwards, a dedicated person must be assigned to direct the lower part and place safety warning signs.

5. Safety protection during the construction of cross-partition beams

A. Personnel protection:

1. Construction personnel must use correct methods when constructing cross-partition beams and dismantling the formwork. Safety protective equipment Wear safety belt and helmet correctly.

2. Safety protective equipment must be qualified. It must be inspected before each use to ensure safety and maintained regularly.

3. The use of seat belts must comply with the principle of hanging at the top and hanging at the bottom, and the correct choice of fastening points ensures absolute safety and firmness.

B. Protection of materials and equipment

1. Templates, equipment, wooden strips, screws, and other small materials must be stacked correctly to prevent falling objects from injuring people and causing accidents.

2. Arrange special personnel to clean construction concrete, wooden strips, nails and other garbage, and centrally stack and transport it.

VI. Construction protection of bridge deck and guardrails

1. During the construction process, suspended construction personnel must firmly use safety protective equipment to ensure the safety of personnel during suspended construction during the vertical removal of formwork and concrete pouring.

2. During the construction process, prevent the formwork concrete ancillary materials from falling and prevent injuries from falling objects from high altitudes.

3. When pouring concrete on the bridge deck, construction workers must use vibrators safely, and at the same time prevent traffic safety of concrete transportation equipment and prevent mechanical injuries.

7. Safety protection at rural intersections on the upper part of XO44 County Road

1. The Construction Planning Department prepares a safe construction plan, and the construction team strictly follows the construction plan and uses the construction plan to carry out on-site bridge deck construction Security protection and security control.

2. Strengthen process construction control during construction, especially the safety protection of pedestrians and vehicles on provincial highways, and have dedicated personnel at the bottom to command and alert.

3. The Safety Section strengthens contact with the highway management department and strives for coordination and command from the highway management department.

4. Use bamboo fences and safety nets to close the gap between the box beams to prevent falling objects from injuring people

8. The construction of the bridge deck system must abide by the principles

1. It is forbidden to throw objects downward without any command.

2. Construction protective helmets and safety belts must be qualified. If damaged, they must be replaced before construction.

3. During the formwork removal process for the wet joints of the bridge deck, the lower part of the bridge must be directed and protected by a dedicated person to prevent falling objects from injuring people.

4. Construction on the upper part of each intersection must be approved by the Construction Planning Department before proceeding.

5. Team safety managers must conduct safety briefing activities before work and keep records.

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