Steel structure engineering construction process and safety management precautions Part 2

 

Safety Management Measures

1. The project team leader or the engineering installation contractor is the first person responsible for safe construction and is fully responsible for the safe construction on site.
2. The on-site safety administrator is a full-time staff member responsible for the supervision and inspection of safe construction.
3. Strengthen the publicity of safe construction, hang slogans and warning signs in prominent positions on the construction site to remind construction workers.
4. Personnel entering the construction site must wear safety helmets.
5. Construction machinery and tools should be routinely checked before use every day, especially steel wire ropes and safety belts should undergo a performance check once a week to ensure they are in good condition.
6. During the installation process, consideration should be given to the safety protection of on-site machinery, equipment, and completed projects.

When the wind speed is 10m/s, sometimes hoisting work should stop, and when the wind speed reaches 15m/s, all work must stop.

7. Gloves must be worn when installing and handling components and plates.
8. If the steel wire rope breaks, breaks wires, and entangles during hoisting, it should be replaced immediately.
9. Special types of work require a valid certificate to work.
10. At the end of a day’s work, the installed building should be properly supported to prevent accidents.
11. Always wear protective glasses when drilling.
12. Do a good job of on-site safety protection measures, erect scaffolding as required and pass inspection before use.
13. When installing wall panels, the operation platform of each layer of the mobile scaffold used should be firmly fixed, anti-slip measures should be taken, the safety rope should be pulled, and the safety belt should be buckled.
14. The mobile scaffold has two or more pull points with the wall, and two braces are set on the outside. The brace needs to be fixed on a solid ground with bearing capacity.
15. Before moving, clear the obstacles on the road ahead, fill in the potholes, and compact the road surface before moving forward.
16. Before implementing each task, safety matters should be repeatedly explained to the installation workers.

Construction Method

For steel structure installation, first comply with the axis and foundation ground elevation of the concrete foundation, adopt the method of hoisting in parts, first hoist all steel columns, after correction and fixation, hoist steel beams in order, adjust as you hoist, then install and fix, and finally hoist the roof support and

Construction Sequence

On-site hoisting is divided into two construction units, using a 50T crane, hoisting from east to west.

Principles and Requirements of Construction Management

A. Standard operation, process standard, firm and solid, beautiful appearance, customer satisfaction, company satisfaction, one-time pass of project quality acceptance.

B. The construction quality passes the acceptance at one time. If it does not meet the acceptance standard, the project team will rectify it within a time limit, and the cost will be borne by the project team. If the rectification causes the construction period to exceed the contract stipulation and needs to bear the breach of contract responsibility, the breach of contract responsibility shall be borne by the project team.

C. If the damage of materials leads to a decline in project quality, the project team shall bear all responsibilities.

D. The specific requirements for construction quality shall be implemented in accordance with the first paragraph of Article 4.

(1) The setting out and line setting are accurate, and the pile foundation is solid and accurate. If an error occurs causing material waste and rework, the responsible person shall bear all responsibilities and deduct a minimum of 200 yuan at a time.

(2) It is required that the hoisting is vertical and parallel, the angle is accurate, the bolts are tightened, and the structure is solid. Otherwise, the responsible person shall bear all responsibilities and deduct a minimum of 200 yuan at a time.

(3) It is required that the welding is standardized, solid and beautiful, without false welding, cracks, and slag inclusion. Otherwise, a minimum deduction of 50 yuan at a time, and the responsible person shall bear the cost of rework materials. If a safety accident is caused due to poor welding, the responsible person shall bear all responsibilities.

(4) The splicing and edging are vertical and parallel and seamless, the surface is not wrinkled, the rivet nails are required to be solid and firm and arranged in a straight line, to be vertical and parallel, the spacing and tightness are consistent, and they must not be arranged in a wave shape and diagonal line. Otherwise, a minimum deduction of 50 yuan will be deducted for each discovery.

(5) It is required that the paint is brushed in place and the color difference is consistent with the main body, and the foam glue and glass glue are processed correctly. Otherwise, a minimum deduction of 20 yuan will be deducted for each discovery.

(6) At the completion of the project, it is required to clean up the ground hygiene and wash and deal with wall dirt. Otherwise, a minimum deduction of 20 yuan will be deducted for each discovery.

Preparation before Installation

A. Construction of column corner bolts;

B. Formulate installation plan and component plan, organize construction well;

C. Check that the steel structure components are delivered to the installation range in order.

Installation Construction Process

A. Steel column installation: Before hoisting, first determine the hoisting point position of the steel component, determine the binding method, take protective measures during hoisting, after the steel column is hoisted, when the column foot and the anchor bolt are about 30cm-40cm, correct it, slowly lower the hook into place, after correction, tighten the bolts, temporarily fix it and you can unhook;

B. Steel beam hoisting: Steel beam hoisting is carried out after the column is rechecked, using two-point symmetrical binding to hoist and install in place, after hoisting, when it is 10cm from the column datum surface, slowly put it in place, after adjustment and correction, fix the connection;

C. Wall purlin installation: The purlin has a small cross-section and light weight, and it is generally hoisted by one hook or multiple hooks or manual hoisting. The correction of the purlin is mainly to correct the spacing, size and its own straightness. The straightness can be checked and corrected by pulling the line or steel ruler.

Hoisting Precautions:

(I) Prevent personnel from falling from a height

1. On-site construction personnel should wear safety helmets, high-altitude operation personnel should wear safety belts, and should hang high and use low, and be tied to a safe and reliable place. On-site operation personnel should wear non-slip shoes.
2. There should be obvious signs in the hoisting work area, and a special person should be on guard. Non-hoisting site workers are strictly prohibited from entering. When the crane is working, people are strictly prohibited from standing under the lifting arm, and at the same time, people are avoided from staying within the swing radius of the crane lifting arm.
3. Ladders and hoisting operation platforms for climbing should be firm. When the crane moves the operation platform, people are strictly prohibited from standing on it.
4. During hoisting, high-altitude operation personnel should stand on the operation platform, basket, ladder for operation. When hoisting steel beams, a safety protection bracket should be added on its upper chord, and a safety steel wire rope should be pulled above the person working, so that construction personnel can safely operate on the beam chord. It is strictly forbidden to walk on unsecured components.
5. After the structure foundation is installed and the purlin is installed in place, the safety support on the beam upper chord needs to be removed. Before removing the installation support, a brown rope with a diameter of 15mm and a length of 90m is pulled on the purlin above the entire beam from the bottom of the two sides of the column to hang the safety belt, and then the safety support is allowed to be removed and the remaining purlin above is installed.
6. High-altitude operations must wear safety belts, wear insulating soft-soled shoes, and take safety measures.
7. Before it can be safely walked, the roof panel must be fully connected to the purlin, and each side is connected with other roof panels. It is absolutely forbidden to walk on partially connected or unconnected roof panels. Do not step on the edge rib of the board, the crimp near the edge of the board, and within 5 inches of the edge of the unsecured board.
8. Single-layer roof panels must not be used as work platforms. People are not allowed to stand on insulation cotton without bearing strength
9. Once it is found that the roof panel is left with oily substances, it should be wiped off immediately to prevent slipping or falling. When standing on the edge of the board, workers should always be alert to prevent dangerous situations, use safety belts, safety nets and handrails.
10. People’s hands and feet must stay away from moving heavy objects and lifting equipment. People are not allowed to stand under the hoisting objects and hoisting tools.

(II) Prevent high-altitude falling objects from hurting people

1. High-altitude operation personnel should put all kinds of tools, bolts, etc. in a special tool bag. When transferring items at high altitude, they should hang a safety rope and must not throw them casually to prevent people from being injured.
2. During hoisting, it is not allowed to stack or hang scattered objects on the components. Scattered items should be transferred up and down in a special bag.
3. The component binding must be firm, and the hoisting point should pass through the center of gravity of the component. When hoisting, it should be stable to avoid vibration or swinging during hoisting, it should be stable to avoid vibration or swinging. When the component is in place or fixed, do not untie the hoisting rigging to prevent the component from falling and injuring people.

D. For the hoisting of steel beams, due to the irregular I-beam of the steel beam, the binding point is easy to slide, so a special steel plate δ=14mm thick steel connecting plate is specially made for the hoisting suspension point, and it is tightened with the upper chord of the steel beam with bolts.

E. When hoisting components, the speed cannot be too fast, and it cannot stay in the air for too long. It is strictly forbidden to rise sharply and fall sharply to prevent components from falling off.

F. After the component is installed, check the connection and stability of each component. When the connection is indeed safe and reliable, you can unhook and unload the cable.

G. When hoisting high-altitude docking components, you need to tie the slip rope to control its direction.

H. During rainy day operations, necessary anti-slip measures should be taken, and there should be sufficient lighting for night operations.

4. It is particularly pointed out that for the unhooking and unloading of the sandwich layer during hoisting, the construction personnel should stand on a solid and reliable ladder.
5. It is strictly forbidden to throw materials from a high altitude.

(III) Requirements for lifting equipment operations:

1. During hoisting, the crane should be commanded by a special person. The commander should be in a place where the crane driver can see. He should be able to clearly see the whole process of hoisting. The hand signals of the lifting worker should be accurate, the whistle should be bright, the crane driver should concentrate, obey the command, and must not leave the post without authorization.
2. During the hoisting process, when the equipment fails and the operation is interrupted, measures must be taken for treatment, and the components must not be left in the air for a long time.
3. Hoisting operations are prohibited when the wind force is greater than 6.
4. Non-professionals are not allowed to enter the cab or operate the crane without authorization. When the crane stops working, the swing and walking mechanism should be braked.
5. Lifting equipment is not allowed to work on a slope, and it is not allowed for the crane to have too much difference in height on both sides.
6. If the site conditions are poor and the soil is loose, although the crawler crane has a walkway board for padding, the soil will become softer after rain. In order to prevent the crawler crane from tipping over during walking and hoisting, the site needs other machinery to cooperate in re-leveling and compacting to avoid accidents.

(IV) Prevent the structure from becoming unstable after hoisting

1. After the component is hoisted into place, it should be temporarily fixed or reliably connected after the initial correction. The fixed tool or other stabilizing device can be removed only after the final stabilization.
2. After the roof component is hoisted, the fixing system should be carried out in time and the roof support system should be pressed to maintain the structural stability.

Installation and Correction

A. Steel column correction: The verticality of the steel column is corrected by a theodolite, and the deviation and elevation can be corrected by a jack. After the correction is correct, it is immediately fixed with fasteners, and the base is fixed with fine stone expansive concrete after fixing;

B. Steel beam correction, the axis and verticality of the steel beam are corrected by measurement, and it is immediately fixed after correction.

Six, the installation of wall sandwich panels

1. Preparation before construction

A. Before the construction of sandwich panel enclosure, corresponding construction drawings should be formulated, and according to the design documents, organizational design should be compiled and technical training and safety production briefing should be conducted for construction personnel;

B. Check the specifications and quantities of various materials in detail according to the documents, and repair and replace damaged sandwich panels and flashing boards in time;

C. Various construction equipment should be complete and can operate normally;

D. Remove the welding slag and spatter of the purlin installation weld, and brush the anti-rust paint for anti-corrosion.

2. Sandwich panel construction process

Wall panel installation starts from one end according to the position of the purlin, the panels must be tightly bitten between the panels, and then fixed with screws; waterproof treatment should be done at the joint of the wall panel, and the sandwich panel should be installed with edge laying, edge adjustment, and edge fixing.

Seven, the installation of purlins

The thin-walled steel purlin is light in weight and can be hoisted by manpower during installation. After the installation of a unit’s steel columns and roof beams is completed, the installation of roof purlins can be carried out. The purlin is directly bolted to the purlin support plate during installation. The installation error of the purlin should be within 5mm.

Roof panel installation

1. Roof panel installation: The installation of roof panels is based on the completion of the main steel structure on site, starting from one end of the gable wall to the other end of the gable wall for construction, strictly following the construction drawings for arrangement, strictly prohibiting misplacement and omission, during the construction process, it must be installed by pulling the line, so that the slope direction of the roof panel is always vertical to the ridge, the length of the roof panel is best formed at one time, and horizontal overlap is avoided as much as possible. The roof panel should be handled lightly during manual and hoisting, and wrinkles should not be caused on the roof panel, scratches should be avoided, and the surface paint should not be damaged;
2. Installation of the ridge: Connectors should be set at the end of the roof panel. Before putting the buckle plate, sealant should be applied at the sealing place, then add the sealing strip and press it tightly. The center of the ridge is filled with broken insulation cotton, and the connection between the plates should be sealed;
3. Installation of flashing board: Understand the construction process of the flashing board before installation, cut the flashing board on the structure line according to the length, seal it with sealing glue, and the flashing board trim should be correct, firm, vertical lines, good waterproof effect.

Nine, Steel Structure Paint

1. Process flow:

Base layer treatment — Apply anti-rust paint — Scrape putty — Apply primer — Apply topcoat

Precautions:

A. For steel structure surface treatment, the anti-corrosion coating requires clear instructions in the design drawings;

B. Painting methods: spraying, brushing, rolling, and airless spraying are all possible;

C. The thickness gauge is used to measure the paint, which is generally divided into primer, intermediate paint, and topcoat.