70 dry goods! The key points of safety must be known for the prevention and control of dangerous projects

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In order to avoid the safety risks of dangerous projects, construction enterprises should strengthen the safety management of sub-projects of dangerous projects, conscientiously implement safety production regulations and corresponding rules and regulations, strictly implement supervision, summarize relevant safety points in a timely manner, and effectively prevent the occurrence of safety production accidents.

01

Foundation pit engineering

1. When entering the construction site, you must abide by the safety operation procedures and safety production discipline. Strictly implement the construction organization design and safety technical measures, and no unauthorized modification is allowed.

2. Before the excavation of the foundation pit, it is necessary to check and understand the geology, hydrology, roads, nearby buildings, houses, etc., make records, and observe the changes frequently during the excavation process, find abnormalities, and take emergency measures immediately.

3. Before the operation, it is necessary to comprehensively check whether the excavated mechanical and electrical equipment meets the safety requirements, and whether the drainage, precipitation and water collection measures at the foundation pit site are implemented.

4. In the operation, we should adhere to the principle of layered excavation from top to bottom, slope first, support first, and then excavation, and it is not allowed to damage the slope or collide with the support system or wall protection pile to prevent collapse, and it is not allowed to overdig before support.

5. It is strictly forbidden to overload the soil and stack materials and equipment around the foundation pit, and temporary shed facilities shall not be erected.

6. The submersible pump and power supply wire for foundation pit pumping should be well insulated and wired correctly, and the operators in the pit should return to the ground when pumping, and the mobile pump must be cut off from the power supply first.

7. When the car transports soil and the loader shovels the soil, someone should be commanded, abide by the on-site traffic signs and instructions, and it is strictly forbidden to walk around the foundation pit to carry vehicles.

8. In the process of foundation pit excavation, the bolt should be strengthened in a timely manner according to the design requirements.

9. After the foundation pit is excavated to the design elevation, the bottom of the pit should be fully closed in time, and the foundation construction should be carried out in time to prevent the foundation pit from being exposed for too long.

10. In the excavation process, if stone blasting is required, a special safety operation plan including dosage calculation should be formulated, and the explosion should be approved only after reporting to the public security department for approval, and the transportation, receiving, storage and management of blasting equipment should be strictly followed.

11. There should be ventilation, dustproof, anti-poison and fireproof measures in the deep foundation pit.

02

Formwork engineering and support system

1. Errors should be avoided as much as possible when measuring and releasing the template axis, and a special person must be organized to carry out technical review and acceptance after the measurement and release, and the follow-up formwork can be carried out only after it is confirmed.

2. During construction, the elevation positioning should be carried out in the four large corners of the building and the elevator shaft, and the control points of the lower floor should be guided upward by the laser vertical collimator during the construction of each floor.

3. When supporting the formwork, the horizontal and vertical lines should be pulled, and the vertical verticality control line should be set to avoid the deviation between the position of the axis of the building and the actual position of the column and wall.

4. When making the formwork, the moisture content of the formwork should be strictly controlled, and the support of the beam and column junction should be firm, and the formwork should be tightly jointed and there should be no gaps, so as to avoid the problem of slurry leakage when pouring concrete.

5. During construction, anti-slurry measures should be taken at the splicing position, and foam double-sided tape should be used to pad it between the templates to ensure that the formwork splicing is seamless, tight and firm.

6. When pouring concrete, it should be watered in advance to ensure that the wood formwork is moist and avoid its expansion in the follow-up project, resulting in honeycomb, or even holes and exposed ribs on the concrete surface.

7. Each floor is provided with sufficient elevation control points, the root of the vertical formwork must be leveled, and the elevation mark is set at the top, and the construction is strictly in accordance with the mark.

8, the building floor elevation by the first floor ± 0.000 elevation control, it is strictly forbidden to step by layer upward measurement, in order to prevent cumulative error, when the building height exceeds 30m, should be set up another elevation control line, each floor elevation measurement points should not be less than 2, in order to review.

9. The embedded parts and reserved holes should be compared with the drawings before installation, and accurately fixed in the design position after confirmation.

10. The thickness of the decoration layer should be considered when the stair tread template is installed.

11. The formwork and bracket should have sufficient rigidity, and the formwork structure should be reasonable, so as to prevent cracking and concrete cracks caused by the different deformations between the members of the formwork.

12. The upper part of the beam template and the wall template must be provided with a temporary brace to ensure that the width of the beam and the wall mouth is consistent when the concrete is poured.

13. During construction, the settlement joints should be correctly set and the spacing of the expansion joints should be limited to avoid exceeding the specified range and causing large cracks in the concrete structure and affecting the subsequent construction.

14. The brush release agent should be carried out after removing the remaining concrete slurry on the formwork, and at the same time, it should be forbidden to use waste engine oil as the release agent, and chemicals such as soap, talcum powder, lime water and other products should be used as the release agent.

15. Although the template release agent is easy to coat, it is easy to cause pollution. Therefore, during the painting process, it should be ensured that it is evenly painted, and the joints of steel bars and concrete should not be polluted.

16. The coating method of the release agent can be brushed or sprayed, but each pass should not be too thick, and the second coat should be applied as soon as possible before the first pass is completely cured, so as to make a good combination between the two, so as to avoid peeling and peeling due to the long curing time of the bottom layer.

03

Lifting and hoisting and hoisting machinery installation and dismantling works

1. After the crane arm is extended, or the main and auxiliary arms are all extended, the luffing shall not be less than the elevation angle specified in each length.

2. The site where the crane travels and works should be kept flat and solid, and a safe distance should be kept from the ditch and foundation pit.

3. The load shall not exceed 20% of the rated lifting capacity under this working condition, so as to prevent the overload damage of the lifting mechanism or the overturning accident of the crane.

4. When the water temperature of the internal combustion engine is 80~90 °C, the lubrication performance is good, and when the water temperature reaches 80 °C, it is not allowed to drive at high speed.

5. When abnormal phenomena such as crane tilting and unstable outriggers are found during the operation, the heavy objects should be immediately lowered and landed in a safe area, and emergency braking should not be used to avoid the crane tipping accident.

6. In order to ensure the normal use of the crane, it must be inspected before the crane operation:

(1) There is no loosening of each connector;

(2) The tire pressure meets the regulations;

(3) The wire rope and the connecting parts comply with the regulations;

(4) The safety protection devices and indicating instruments are complete and intact;

(5) Fuel, lubricating oil, hydraulic oil and cooling water are added sufficiently.

7. The wire rope used by the crane should be firmly connected with the drum, and when the wire rope is released, at least three turns should be kept on the drum, and the wire rope should be prevented from ringing, kinking, bending and messing with the rope when retracting and releasing the wire rope.

8. When the wire rope is braided and fixed, the length of the braided part shall not be less than 20 times the diameter of the wire rope, and shall not be less than 300mm, and the braided part shall be tied with thin steel wire. When the rope clamp is fixed, the specification and quantity of the rope clamp matching the diameter of the wire rope should meet the requirements of the specification.

9. Before each shift, the wire rope and the connection part of the wire rope should be checked, and when the number of broken wires reaches or exceeds the requirements, it should be scrapped.

10. In case of severe weather such as wind or heavy rain, heavy snow, fog and above, the lifting and hoisting operation should be stopped. Before the operation after the rain, snow and fog, the operation should be tried to confirm that the brake is sensitive and reliable.

Scaffolding works

04

Erection points

1. The verticality deviation of the pole shall not be greater than 1/200 of the height, and the top of the pole shall be 1.5m higher than the roof of the building.

2. Longitudinal and transverse sweeping rods must be provided at the bottom of the scaffold, wherein the longitudinal sweeping rod shall be fixed on the vertical rod at a distance of no more than 200mm from the surface of the horn block with right-angle fasteners, and the transverse sweeping rod shall be fixed on the vertical rod immediately below the longitudinal sweeping rod with right-angle fasteners.

3. The large crossbar should be located under the small crossbar, and on the inside of the vertical rod, the right-angle fastener should be fastened with the vertical rod, and the length of the large crossbar should not be less than 3 spans and not less than 6m.

4. In the erection, each layer of the outer frame should be firmly tied with the structure in time to ensure the safety in the erection process, and the verticality and horizontal deviation of the rods should be corrected along with the erection, and the fasteners should be moderately tightened.

5. In addition to the top layer of the joint of the scissor brace, the rest of the joints must be connected by butt fasteners, and the scissor brace should be fixed on the extended end or vertical rod of the small crossbar intersecting with the rotating fastener, and the distance between the center line of the rotating fastener and the main node should not be greater than 150mm.

05

Demolition points

1. The scaffolding must be dismantled layer by layer from top to bottom, and it is strictly forbidden to work up and down at the same time, and the wall pieces should be dismantled layer by layer with the scaffolding, and it is strictly forbidden to dismantle the scaffolding after removing the whole or several layers of the wall pieces.

2. When dismantling the scaffolding, the nearby power cord should be removed first, if there is a pre-embedded power cord underground, protective measures should be taken, and it is strictly forbidden to throw fasteners and steel pipes around the power cord.

3. The removal of the pole (6m specification length) must be carried out by 2 people, and the pole within the range of 30cm under the main horizontal pole is forbidden to be demolished by a single person, and it is required to complete the demolition before the step distance of the previous flat bridge, and improper operation is easy to cause a high-altitude fall (including people and objects).

4. The large crossbar, scissor brace and diagonal brace should be dismantled in the middle butt fastener first, and then the end buckle should be unfastened by holding the middle;

5. The connecting wall piece shall not be removed in advance, and it can be removed when it is dismantled layer by layer to the connecting wall piece, and before the last connecting wall piece is removed, it should be set up on the vertical rod after throwing the brace, so as to ensure the stability of the vertical rod in the demolition.

In addition, attention should be paid to preventing the following accidents during the construction of the project to ensure the safety of the project.

01

Fall from a height

1. The upper perimeter and periphery of the working layer must be set up with a temporary guardrail with a height of 1.2m and can withstand 1000N external force in any direction, and the guardrail is enclosed with a dense mesh (2000 mesh) safety net.

2. The side length of the reserved hole with a side length of more than 250mm is made of steel bars that run through the concrete slab to form a protective net, and the surface is sealed with a wooden board as a cover plate and mortar; the hole with a side length of more than 150mm is surrounded by a protective railing and a dense mesh (2000 mesh) safety net, and a safety flat net is hung under the hole.

3. After all kinds of shelves are set up, the project manager department organizes the scaffolding workers and the teams used to jointly inspect and accept, and only after passing the acceptance will they be allowed to operate on the shelves.

4. The temporary ladder used in the construction should be firm, with a step of 300~400mm, and the angle of the ground is 60°~70°, and the foot of the ladder should have anti-skid measures, and the top end should be tied firmly or a special person should be set up for the escalator.

02

Object strikes

1. Personnel entering the construction site must wear safety helmets according to regulations. They should enter and exit and get up and down in the specified safe passage, and should not walk in non-specified passageway locations.

2. A double-layer protective shed should be erected above the safety passage, and the materials used in the protective shed should be able to prevent the penetration of falling objects from high altitudes.

3. The roof of temporary facilities shall not be covered with asbestos tiles.

4. The reserved hole with a side length of no more than 250mm must be closed with a solid cover plate and fixed with mortar.

5. In the process of operation, commonly used tools must be placed in the tool bag, and materials and tools are not allowed to be thrown down or up. All materials should be stacked smoothly, not stacked near the edge and the hole, and should not obstruct the passage.

6. The dismantling or dismantling operation should be carried out under the condition of setting up a warning area and being supervised.

7. During the demolition operation at a high place, the materials and construction waste under the demolition should be cleaned up and transported away in time, and should not be arbitrarily placed or discarded on the walkway.

03

Electric shock

1. All line laying must be carried out in accordance with technical regulations, keep a safe distance according to the specifications, and take effective measures to isolate and protect when the distance is insufficient.

2. Sufficient safety distance must be maintained between the charged body, between the charged body and the ground, between the charged body and other facilities, and between the staff and the charged body.

3. In places where there is a risk of electric shock or places that are prone to misjudgment and misoperation, as well as at the scene where there are unsafe factors, set up eye-catching text or graphic signs to remind people to identify and be vigilant against risk factors.

4. Take appropriate insulation protection measures to seal or adjab the live conductor, so that the electrical equipment and lines can work normally and prevent personal electric shock.

5. Adopt appropriate protective grounding measures to electrically connect the exposed conductive part (metal shell or metal structure of the equipment) of the electrical device that is usually not electrified, but may be brought with dangerous ground voltage due to insulation damage, so as to reduce the risk of electric shock.

09

坍塌

1. The foundation of the project is a bored pile, the excavation depth of artificial earthwork is 0.9m, and the natural low floor is less than 0.5m, so the special construction plan of the earthwork can be ignored.

2. After the excavation of the foundation pit, the foundation should be built in time and should not be exposed for a long time. After the foundation construction is completed, the backfilling work of the foundation pit should be grasped. When backfilling the foundation pit, it is necessary to remove the debris in the foundation pit that does not meet the backfill requirements in advance. Perform evenly on the corresponding sides or sides at the same time.

3. Before excavating, the surrounding environment should be carefully checked, and the operation should not be carried out under the building behind the dangerous rock.

4. The distance between the two people should be kept at 2~3m during manual excavation, and should be dug from top to bottom, and it is strictly forbidden to steal rock and soil.

5. When the scaffold is erected, it should be erected row by row, span by span and step by step according to the requirements of the basic frame unit of the form, and the rectangular peripheral scaffold should be extended from one of the corners to the two directions to ensure the stability of the erected part.

6. The operation on the frame should be used according to the load specified in the specification or design, and it is strictly forbidden to overload, and the load on the frame should be evenly distributed to avoid the load being concentrated on one side.

7. When working on the frame, the basic structural rods shall not be dismantled at will, and some rods must be dismantled due to the needs of the operation, and the consent of the chief engineer of the project must be obtained, and reliable reinforcement measures must be taken before they can be removed.