Box-type substation installation and cheme

1 Foundation excavation

The method of mechanical excavation and manual cooperation with excavation is adopted for the box variable foundation pit, and the slope of the foundation pit slope is 1:1 during excavation. The excavation depth of the excavator is to the bearing layer, and the remaining part is manually cleaned until the excavation reaches the embedded flat steel bottom. The width of the sink is 100mm.

2 Grounding Engineering

In order to facilitate the installation of equipment, the flat steel extends about 1 meter from the top layer of the foundation. Flat steel lap length is not less than 100mm, at least three edge welding, welding for anti-corrosion treatment. Grounding and construction according to the construction installation engineering Atlas JD1-305, all fasteners used in the package shall be hot-dip galvanized. The grounding resistance of the distribution room should not be greater than 1 bar, and the welding operation of the grounding network construction should be welding by professionals.

3 Cushion construction

In this project, 100 thick C15 concrete cushion is used as the foundation cushion, and measures should be taken to ensure the flatness of the surface of the cushion during the construction of the cushion. The foundation formwork of this project adopts wooden mold. The wooden mold is reinforced with steel pipes, and the position of the foundation should be strictly controlled during construction to prevent the displacement of the template.

4 Binding the base steel bars

The bottom plate is 200mm thick and double-layer bidirectional steel Φ14@200. The production and binding of steel bars should be constructed in strict accordance with the design requirements, and the next process can be constructed only after the completion of the binding and acceptance.

5. Foundation concrete pouring

In this project, C25 concrete is used for the base plate of the box transformer. During the pouring process, the samples should be carried out in accordance with the concrete pouring operation rules. The insertion points of vibrators should be uniform during the pouring, especially the concrete near the embedded flat steel to ensure the compaction. After the foundation concrete is poured, the surface is illuminated, and a certain slope is formed to the water trough next to the foundation, and the water trough is tilted to the direction of the sewage outlet.

6 Foundation drainage system and masonry walls

In order to prevent water seepage in the pit during construction rain and snow, resulting in corrosion of the equipment, it is required to build a brick wall with a width of 370 and a height of 2450mm along the perimeter of the foundation pit, bury a diameter of 110mm at the top, and a wall thickness of 2mm. Plug the cable tightly with cotton silk after threading the pipe, or other fireproof. And make 1:2.5 cement mortar waterproof coating inside and outside, 20mm thick, the mortar is required to be full, there should be no gaps. The maintenance wall is provided with a steel ladder, which has two vertical ribs of Φ22 and three level steel, and the ladder is Φ14 secondary steel, with a distance of 200mm. The bottom water tank is connected with the embedded sewage pipe.

7 Concrete roof pressing

The top surface of the brick wall is topped with 370*200 concrete, the top is C25 concrete, the longitudinal steel is 4Φ14, and the stirrup is 2 steel Φ14@200. The rigid plate of 200*200*12 is evenly embedded on the press top, and the claw hook (round steel 4 Φ14, L=15cm) is buried in the ring beam on the back of the embedded rigid plate. When the masonry height of the brick wall does not exceed 20mm, the support mold pouring begins.

8 Quality assurance measures

1. After the grounding device is installed, the grounding resistance can be tested only when the ground humidity reaches the specifications in clear weather. If there is a grounding device whose grounding resistance value does not meet the requirements, the corresponding grounding pole and grounding bus should be added according to the regulations until the grounding resistance value meets the design requirements.

2. The height of wall masonry should not exceed 1.2m per day.

3. When backfilling earth, strictly check the use of backfill materials, and do not contain plant residues, garbage and other magazines.

4. Earthwork backfill must be compacted in layers according to regulations to ensure the compactness of backfill.

5, the corner of the masonry should be laid at the same time. When the masonry can not be done at the same time, it should be left in accordance with the regulations.

6, the temporary construction hole on the wall, its side from the intersection of the wall should not be less than 500mm, the net width of the hole should not exceed 1m.

9 Security Measures

Before construction, the person in charge of construction should make a special technical safety disclosure to the operator.

On-site electrical equipment should have leakage protectors, and cables should be reliably insulated.

The construction personnel in the foundation pit, especially the drainage construction personnel, must do a good job of anti-shock measures, wear insulation gloves, wear insulation shoes.

Before removing the formwork, it must be confirmed that the concrete strength meets the requirements, and can only be carried out after the demoliting application is approved. There must be a concrete strength report, and the concrete strength does not meet the requirements.

Safety inspection shall be carried out before masonry, and construction shall be carried out only after the site operating environment, safety measures, protective equipment and machinery meet the requirements.

Scaffolding should be set up when building walls.

The height of stacked bricks on the scaffold shall not exceed 3 leather side bricks, and the operator on the same scaffold board shall not exceed two people.

Masonry shall not be trampled during construction.