Construction design scheme of site fence

1, measuring line

According to the site layout plan, the positioning of the fence is first controlled. Based on the north-south axis and site control data, the west control baseline was derived. Two points are drawn to determine a straight line as the control line of the west side guard net, and the extension control line is 2-3 meters as the control pile. Use a steel tape measure to determine the focus position on the west side of the control line. In the same way, the remaining point lines were measured using a theodolite.

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2, earth excavation

According to the measured straight line of the protection net, the protection net is divided into various segments according to the actual conditions of the atlas and drawings. The segment length is 3300 mm, and the position of each midpoint is determined. Due to the small depth of excavation, only the working surface can be left. The size is set to 800Ã—800 mm. During the excavation process, the edges are trimmed and controlled.

3, install the template

Because this project has a small amount of template and is a basic small template, no complicated calculation is required. This template adopts the steel formwork support system. Before the assembly, the site should be compacted. After the assembly of the formwork, the dimensions should be checked, and the separating agent should be evenly applied. When installing, the axes, template edges, horizontal control elevations, and template bottoms are level and firm. If the requirements are not met, the cement mortar leveling layer shall be used. The ground anchors used for column reinforcement shall be well embedded and ready for use. Installation column template, column piece mold â†’ installation column hoop â†’ calibration column placement, vertical and position â†’ comprehensive inspection and calibration â†’ group fixation â†’ pre-test

4, concrete construction (C15)

The project plans to use commercial concrete. The placement of concrete should be carried out in layers. Intermittent time should not exceed the initial setting time of the concrete. Generally, it does not exceed two hours. Layers of material are stratified and the thickness of each layer is the effective vibration length of the vibrating rod. With a plug-in vibrator, the insertion distance is not more than 1.25 times the length of the vibrator. Try to avoid the collision of embedded parts, pre-embedded bolts, and prevent the embedded parts from shifting. The concrete that has been poured should be covered and watered in about 12 hours, and normal temperature maintenance should not be less than 7 days.

5, the installation of steel

In the template set the center line, embedded 300 Ã— 100 Ã— 5 steel plate. The position and elevation of the school board should be maintained until it is fixed.

6, split template and earth backfill

(1) Remove the template

When the concrete strength can ensure that the corners of the concrete can not be damaged due to the demolition of the template, the concrete can be removed. Before the removal of the mould, special personnel should check the strength of the concrete. When dismantling the concrete, remove the concrete from the side and do not use a sledgehammer or a crowbar. Oh, so as not to cause damage to concrete corners. After 7 days of maintenance, demolish the template according to the strength.

(2) Earthwork backfill

This project uses the original soil for backfilling. The backfill soil shall be paved and compacted, and shall not be greater than 200 mm when manually backfilled, and each layer shall be tapped at least 3 times. Ask for a half-hour pressure. When backfilling, the construction of backfill soil should be carried out until the foundation reaches a certain strength, so as to avoid damage to the structural foundation.

7, welding installation

According to the elevation size, -200Ã—20 steel plates and 300Ã—100Ã—5 steel plates are welded. Then welded Î¦50 steel pipe according to the position and size. Welding L160Ã—20 angle steel. Welders must hold certificates and work sites to prevent accidents such as electric shocks and burns. The grades of steel bars must meet the design requirements, and there are product certification inspection report and re-inspection report. Steel plates used for embedded parts must not have cracks, rust, or deformation. Select the appropriate welding process during welding, the diameter of the welding rod, the welding speed, and the length of the welding arc, verified by the welding process test.

8, install the finished steel wire mesh

Finished steel wire mesh should be protected after being transported to the site. It should not be stepped on and squeezed, and then cut in segments. After the repair is completed, perform the installation calibration.

9, protection and maintenance

The welding of steel parts shall be done by troweling, and rust prevention shall be carried out in accordance with the requirements of the drawings when all works are basically completed.