Tumu people, do you really know "Three Treasures, Four Mouths and Five Borders"?

Definition of "Three Treasures", "Four Ports" and "Five Linbian"

"Three Treasures" mainly refers to the correct use of protective equipment such as safety helmets, safety belts, and safety nets; "Four Ports" It means that the protection of various openings such as stairwells, elevator shafts, reserved openings, passage openings, etc. should meet the requirements; "five edges" refers to edge parts such as deep foundation pits, balconies, awnings, floor slabs, roofs, unloading platforms, etc. If not properly protected, there will be hidden dangers in a series of accidents such as falling from heights and being struck by objects. To this end, the project department established a special management team of "Three Treasures", "Four Ports" and "Five Borders" headed by the safety officer and composed of team leaders.

"Three Treasures" Protection

A safety helmet must be worn when entering the construction site, and a safety belt must be worn when working at heights. There should be a sign saying "You must wear a safety helmet when entering the construction site" at the entrance and exit gates of the site. Construction workers call hard hats, seat belts, and safety nets the "three treasures" that save their lives.

(1) Safety helmet

1. Safety helmet requirements: There should be manufacturer name, trademark, model, production date, license number, industrial production license number, safety production License number, factory inspection certificate, test report, each helmet has batch verification by the inspection department and factory inspection certificate and approval certificate.

2. Impact resistance: After the helmet is treated at temperatures of +50°C, -10°C, or immersed in water, then lift a 5kg steel hammer from a height of 1m. When falling freely and impacting a helmet, the maximum impact force should not exceed 500kg (5000N or 5kN), because the human cervical spine can only withstand an impact of 500kg, and it will be vulnerable to injury if it exceeds 500kg.

3. Penetration resistance. According to the different materials of the helmet, it can be treated by three methods: +50℃, -10℃ or water immersion. Use a 3kg steel cone to drop freely from a height of 1m above the helmet. The steel cone will penetrate safely. cap, but not touching the scalp. This requires that when the selected safety helmet is worn, the horizontal distance between the top of the hat lining and each side of the inner surface of the hat shell should be maintained at 5 to 20 mm.

4. Good low temperature resistance. When the temperature is below -10℃, the impact resistance and penetration resistance of the helmet do not change.

5. The lateral rigidity can meet the specification requirements.

6. Safety helmets should be used correctly, worn properly, and fastened. The chin strap must be buckled under the chin. It is not allowed to litter or litter, it is used for sitting and cushioning, and helmets with missing linings, missing straps or damaged ones are not allowed to be used.

(2) Safety belts (safety belts must be worn when working at heights above 2m)

1. Safety belt requirements: The length of safety ropes used by erecters should be 1.5 to 2m, which is safe and The belt body should be sewn with permanent trademarks, certificates, and inspection certificates. The certificate should indicate: product name, year and month of production, tensile test, impact test, manufacturer name, inspector name. When the safety belt enters the site, there should be quality certificates, test reports, production licenses and other quality certification documents.

2. Seat belts should be hung high and used low to prevent swings and collisions; various parts of the seat belts must not be removed at will.

3. After the safety belt has been used for two years, the user should select a certain proportion of the quantity according to the size of the purchased batch, conduct a random inspection, and use an 80kg sand bag to do a free fall test. If it does not break, it can Continue to use, but the randomly inspected sample belts should be replaced with new lanyards before they can be used; if the test fails, the purchased batch of seat belts should be scrapped.

4. Frequently check the appearance quality of the seat belt. If it is found to be mildewed, hard and brittle, broken, damaged or has an odor, it should be replaced immediately.

5. Seat belts should be scrapped after 3 to 5 years of use.

6. Seat belts should be used correctly. Fasten the seat belt, hang and fasten the safety hook. The site must be equipped with safety belts that comply with national standards. During construction, high-altitude operations, climbing operations, and independent suspended operations, Operators should wear seat belts and hang them on a solid and reliable object when in use. After use, a designated person should be responsible for safekeeping.

(3) Safety net

1. Safety net requirements: The mesh density is not less than 2000 mesh/10cm*10cm, and there should be batch verification and factory inspection by the nationally designated supervision and inspection department. Certificate of conformity, test report and license.

2. Penetration test: Place the 1.8m*6m safety net at an angle of 30° with the ground, and straighten and fix the four sides.

At a place 3m above the center of the net, use a 5kg steel pipe of Ф48*3.2 and drop it freely. If the net does not penetrate, it is qualified. If the net penetrates, it is unqualified. For the penetration test, a Ф48*3.2 steel pipe must be used, and the burrs on the edge of the pipe mouth must be smoothed. The cross-section of the steel pipe is a 3.5mm wide side ring. When a 5kg steel pipe falls onto a safety net at an angle of 30° to the ground, its penetrating force only passes through a small part of the cross-section of the steel pipe and acts on the net. Because the area is small, the penetration force is very large. If you choose a steel pipe with a thick wall or a steel pipe with a large diameter, the penetration force will be weakened due to the large contact area during penetration.

3. Impact test: Place the dense mesh safety net horizontally and tighten the four sides. A 100kg sandbag falls freely 1.5m above the center of the net. If the length of the edge of the net torn is less than 200mm, it is qualified.

4. The form and performance of the safety net. At present, the safety nets used on construction sites can be divided into two types: flat nets and vertical nets according to their forms and functions. Since the stress conditions of these two types of nets are different during use, their specifications, sizes and strength requirements are also different:

Flat net: refers to its installation plane parallel to the horizontal plane, mainly used to accept people and the fall of things.

Vertical net: refers to its installation plane perpendicular to the horizontal plane, mainly used to prevent people and objects from falling.

5. The structure and materials of the safety net. The safety net is composed of a net body, side ropes, tethers and tendons. The net body is made of mesh ropes and has a rhombus or square mesh. The distance between two adjacent knots of a knitted object is called the mesh size; the mesh ropes on the surrounding edges of the net body are called side ropes. The size of the safety net (nominal size) is determined by the size of the side rope; the rope that fixes the safety net to the support is called a tether. In addition, any rope used to increase the strength of the safety net is collectively called a rib rope.

The material of the safety net is required to have a small specific gravity, high strength, good wear resistance, high elongation and strong durability. In addition, it should have certain weather resistance, and its strength will not decrease significantly after being exposed to moisture. At present, safety nets use chemical fibers as the main material. All ropes on the same safety net must be made of the same material, and the wet-to-dry strength ratio of all materials must not be less than 75%. Usually, synthetic chemical fibers such as vinylon and nylon are used as mesh ropes. Polypropylene is prohibited from use due to its unstable performance. In addition, as long as it meets the requirements of relevant international regulations, cotton, linen, palm and other plant materials can also be used as raw materials. Regardless of the material used, the weight of each safety flat net should generally not exceed 15kg and must be able to withstand an impact of 800N.

There are two specifications of dense mesh safety net: ML1.8m*6m or ML1.5m*6m. The weight of 1.8m*6m dense mesh is greater than or equal to 3kg. The mesh number of the dense mesh safety net is greater than 2000 meshes on an area of ??10cm*10cm=100cm2 anywhere on the network.

6. Use dense-mesh safety nets to completely seal the outside of the project under construction and the outside of the external scaffolding, so that the construction site can be horizontally protected from open protection with large mesh flat nets, with railings or small The mesh vertical net is used as a semi-enclosed protection to achieve fully enclosed protection. This not only creates a safe working environment for workers, but also adds a landscape to the city's civilized construction. It is not only a qualitative change in construction safety production, but also a leap in safety production work. Be sure to choose a dense-mesh safety protection net that meets the requirements, and never use substandard products for the sake of cheapness.

"Four Ports" Protection

During the construction of construction projects, there are often various openings at the construction site. Construction workers work next to the openings, which can easily cause confusion between people and things. Fall hazards and personal safety hazards should be protected when working at the entrance.

(1) Types of openings

Protective measures for opening operations include setting up protective railings, gates, grilles and erecting safety nets, etc., as well as protective facilities under different circumstances.

1. The openings of various boards and walls should be equipped with solid cover plates, protective railings, safety grids or other anti-fall protection facilities according to their size and nature.

2. At the entrance of the elevator shaft, guardrails or fixed gates and tool gates are set up according to specific circumstances. There is a horizontal net on each floor in the elevator shaft, and a scaffolding board is set up on every other floor for complete closure. Floor scaffolding is erected in the shaft.

3. Pile openings where concrete is not poured, pits and slots that are not filled with soil, as well as windows, floor doors, septic tanks, etc., must be used as openings and take protective measures that comply with regulations.

4. In addition to protective facilities and safety signs, red light warnings should also be set up at night at various openings and openings with a depth of more than 2m near the construction site and site passages.

5. The material lifting and loading port should be equipped with a safety door with an interlocking device, and a rope-breaking protection device or a safe parking device should be used; the walkway plate at the entrance should be parallel to the building and fully fixed and firmly fixed , protective railings and toeboards that meet the requirements should be installed on both sides, and both sides should be closed with dense-mesh safety nets.

(2) Requirements for safety protection measures at the entrance

When operating at the entrance, measures such as setting up protective railings, stamping parts, hanging safety nets and installing gates shall be adopted according to the specific conditions.

1. Bamboo, wood, etc. can be used as cover boards to cover the openings in the floor. The cover must be able to maintain a balanced position around it and have measures to fix its position.

2. The opening with a short side length of 50 to 150cm must be equipped with a network of steel pipes fastened with fasteners, and covered with bamboo fences or scaffolding boards. Steel bars that penetrate the concrete slab can also be used to form a protective net. The spacing between the steel bars should not be greater than 20cm.

3. For holes with a side length of more than 150cm, protective railings should be set up around them, and a safety net should be stretched under the hole.

4. For vertical openings in walls, etc., all openings that are floor-to-ceiling should be equipped with switch-type, tool-type or fixed-type protective gate networks. The spacing should not be greater than 15cm, and protective railings can also be used. , with a foot guard (fence) underneath.

5. For vertical openings such as the lower edge to the floor or window sill with the bottom lower than 80cm, if the side drop is greater than 2m, a 1.2m high temporary guardrail should be installed.

(3) Structural requirements for opening protection

Generally speaking, the structural forms of opening protection can be divided into three categories:

1. Opening protective railings, usually Steel pipe is required.

2. Use concrete floor slabs, use steel mesh, or use structural steel bars or encrypted steel mesh, etc.

3. Wooden gates, iron gates and various open or fixed protective doors can be installed at the vertical elevator shaft entrances and openings. The mechanical calculation of the protective railings and the structural form of the protective facilities should comply with the requirements of the regulations.

(4) On-site opening protection settings

1. The site must pay attention to the protection of the "four entrances" along the edge. Steel pipes and iron plates painted in red and white should be used as guardrails during protection. Material.

2. Stair steps and platform edges must be equipped with strong and reliable temporary guardrails. 1.2m high-level poles and 30cm-high kick poles. The inside of the poles must be covered with dense mesh. The derrick mouth must be Install a 1.2m high safety protection door. The distance between the door grids should not be greater than 15cm. A safety plywood (or scaffolding piece) should be installed on each floor of the derrick entrance. The gap between the plywood and the derrick entrance should not be greater than 10cm. When the protection height Hard materials such as scaffolding boards shall not be used for horizontal protection when exceeding one standard level. The loading platform at the derrick mouth shall be constructed with floor-to-ceiling steel pipe frames. The protective railings and gates shall comply with the regulations, be neat and firm, and be compatible with the standardized management of the site. The experience is collected into tooled and stereotyped protective equipment, which is safe, reliable, neat and beautiful, and can be used repeatedly.

3. The protection of reserved openings, pits, and wells should be standardized in the unit or construction site based on the size of the opening and operating conditions. Workers are not allowed to find temporary materials to cover at will. Practice to prevent potential accidents due to looseness and looseness. Small openings within 1.5 square meters can be covered tightly with shaped materials such as formwork or steel plates, or they can be temporarily blocked, or steel bars that penetrate the concrete slab can be used to form a protective net, covered with bamboo fences or scaffolding boards, with a side length of more than 1.5m. For holes or holes with an area of ??1.5 square meters, 1.2m high body protection and 30cm high kick poles should be set up around the hole. Safety nets should be hung all over the inside of the poles, and safety warning signs should be hung.

4. Passage entrance protection: A protective shed should be set up at the entrance of each staircase or at a location where people come and go, and eye-catching signs should be hung on the upper and lower floors.

"Five edge" protection

During the construction of construction projects, construction workers spend most of their time working at the edges or openings of various parts or objects on each floor of the unfinished building. In situations where falling accidents are very likely to occur during construction, protection is required and protection regulations must be strictly followed.

(1) Protective railings

This type of protective facilities has a simple form and structure. The materials used are commonly used at construction sites. There is no need to purchase them specially and it can save costs. The important thing is The effect is better. Protective railings must be installed in the following three situations:

1. Balconies without railings, around material tables and various platforms, awnings and overhangs, roofs and floor edges without external scaffolding, and Protective railings must be installed around water tanks and water towers.

2. Edge protective railings must be installed at the stair entrances and ladder sections in layered construction. Formal railings or temporary railings should be installed at the stair entrances on the top floor according to the progress of the project structure; protection should also be installed next to the ladder sections. railing.

3. Vertical transportation equipment such as derricks, construction elevators and other passages connected to the building must also be equipped with protective railings on both sides, and foot guards and foot blocking bamboos must be added at the lower part of the guardrails. Fence or metal mesh.

(2) Material selection and structural requirements for protective railings

The railings used for edge protection consist of railing posts and two upper and lower crossbars. The upper crossbar is called a handrail. The material of the railing should be selected according to the requirements of the specifications and standards. In addition to meeting the mechanical conditions when selecting the material, its specifications, dimensions and connection methods should also meet the structural requirements. It should be fastened without shaking, able to withstand sudden impacts, and block people when possible. It must have a certain degree of durability to prevent falling conditions and prevent materials from falling.

(3) When erecting edge protection railings:

1. The height of the upper pole from the ground is 1.2m, the height of the lower pole from the ground is 0.5~0.6m, and the slope is greater than 1: On the roof of 2.2, the protective railings should be 1.5m high and a safety net should be hung. Except according to the design calculation, if the length of the crossbar is greater than 2m, a railing must be added.

2. The fixing of railing posts should meet the following requirements:

1) When fixing around the foundation pit, steel pipes can be used and driven into the ground to a depth of 50 to 70cm. The distance between the steel pipe and the edge should not be less than 50cm. When sheet piles are used around the foundation pit, steel pipes can be driven outside the sheet piles.

2) When the concrete floor, roof or wall is fixed, embedded parts can be welded with steel pipes or steel bars. When using bamboo or wooden railings, you can weld 30cm long ∟50*5 angle steel on the embedded parts, drill a hole on the top and bottom of it, and then use 10cm bolts to fasten it to the bamboo or wooden poles.

3) When fixing on masonry such as bricks or masonry, 80*6 bent flat steel with suitable specifications can be built into the concrete block with embedded iron in advance, and then the above method can be used fixed.

3. The overall structure of the fixation of the railing posts and their connection with the crossbar should enable the protective railing to withstand an external force of 1000N in any direction at any point on the upper pole. When the location of the railing is likely to cause crowding, vehicle impact or object collision, the cross-bar section should be enlarged or the column spacing should be enlarged.

4. The protective railing must be closed with a safety net from top to bottom.

These requirements are based on both practice and calculation. For example, the height of the pole on the railing is to prevent the center of gravity from being higher than the crossbar when the person is hit by the impact, causing the person to fall off the pole. The force strength of the railing should be able to prevent it from being damaged when it is suddenly impacted by a large person; the railing column should be fixed so that it will not be knocked down or pulled out when it receives the largest possible impact. This is Taking into consideration the national conditions, it is only required that its overall structure must be able to withstand large impacts.

(4) Setting of protective railings

Protective railings for edge operations are mainly used to prevent people from falling. They can withstand a certain amount of impact or impact and can withstand 1000N of force performance. External force can ensure safety. When there are no protective facilities on the edge protection working surface or the height of the fence is less than 80cm, edge protection railings must be erected in accordance with regulations. The requirements for erecting edge protection railings are:

1. The protective railings are from top to bottom. It consists of two lower crossbars and railings. The height of the upper bar from the ground is 1.0m~1.2m, and the height of the lower bar from the ground is 0.5m~0.6m. When the length of the crossbar exceeds 2m, railing posts must be added.

2. The overall structure of the railing posts and their connection with the crossbar should be such that the protective railings are positioned anywhere on the upper pole;

3. The protective rails must be tightly secured from top to bottom. The mesh should be closed, or a tightly fixed foot guard with a height of not less than 18cm should be installed under the railing.

4. Protective railings should be painted in eye-catching safety colors.

5. Attached stair and passageway protective structures

Acceptance and maintenance

The correct wearing of safety helmets should be supervised by employees, inspected by the team leader, and the project Managers supervise and inspect to ensure everyone wears a safety helmet. The fourth port and the edge should be protected on each floor and inspected and accepted. Inspection and maintenance should be strengthened on a regular basis. Full-time safety personnel should conduct special inspection and maintenance. After the project is capped, inspection and maintenance are generally performed once a month

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