Available range
Manufacture and installation of concrete cover plate for cable trench and other passages in substation engineering
Process flow:
Construction preparation-angle steel frame fabrication-angle steel frame galvanizing-steel bar fabrication and installation-concrete pouring-curing-cover plate installation-quality inspection and evaluation.
Description of process flow and main quality control points:
Construction preparation? (1) material preparation: sand and stone should have a retest report, and cement should have a factory certificate and a retest report; The reinforcement shall be inspected for appearance and data (quality certificate) and passed the second interview after the sample is submitted; Angle steel should have a certificate of approval, appearance inspection should be carried out when entering the site, no deformation and warping phenomenon, specifications, models and wall thickness should meet the design requirements. Covered electrode should have a certificate of approval, and the welder should have a job certificate.
(2) Preparation of prefabrication site: The prefabrication site shall be located in the substation area that does not affect the construction site, and the site size shall be determined according to the prefabrication quantity and service time. The surface of the site should be calendered, and the calendered surface should be flat, smooth and solid (cable ditch cover plate production site
(3) Technical preparation: 1) Drawing review: Do a good job in drawing review in strict accordance with the requirements of State Grid Corporation's Guidelines for Construction Technology Management of Electric Power Construction Projects (hereinafter referred to as the Guidelines). ? 2) Technical disclosure: Technical disclosure shall be made for all subdivisional works according to the guidelines. The content of technical disclosure should be substantive, targeted and instructive, and all personnel involved in the construction should participate in the disclosure and sign it to form a written disclosure record.
Make an angle iron frame According to the setting-out size of the frame, the angle iron shall be cut by a special person, the two ends of the angle iron shall be cut at 45 degrees, and the angle iron frame shall be welded at 45 degrees. There should be no overheating, undercut and slag inclusion when welding the angle iron frame. When welding, in order to ensure the unity of the size and deformation of the angle iron frame, a flat steel plate can be placed at the bottom of the frame, and the wire is stretched on the steel plate, and the angle steel is used to weld the angle iron frame model around. When welding, put the angle iron into the model for welding. In order to ensure that the concrete in the frame is firmly bonded with the galvanized frame, several threaded steel bars can be welded on the inside of the frame. After the frame is welded, it will be sent to the galvanizing plant for hot galvanizing treatment. The frame is easy to deform after zinc plating. Before pouring, it should be corrected to make the diagonal, flatness and size of the frame meet the requirements.
Fabrication and installation of steel bars
According to the requirements of the drawings, steel bars, hook I-beams, steel bar nodes are all bound with lead wires, and the steel bars reserved for mesh bars and angle steel frames should also be bound.
Concrete pouring: the angle steel frame is horizontally placed on the prefabrication site, and the bottom of the frame is paved with 3mm thick rubber skin to ensure that the bottom of the molded cover plate does not leak slurry, and the bottom surface is flat and smooth, and the concrete at the bottom is not higher than the angle steel frame.
In order to ensure the uniform color of the surface of the concrete protective layer, the concrete raw materials shall enter the site once as far as possible and be stacked separately. The concrete raw materials shall be measured by special personnel and evenly mixed.
Spread a layer of concrete in the angle steel formwork, vibrate it with a flat vibrator (small flat plate) for compaction, put the steel mesh into the formwork, then add the concrete to spread the angle steel cover plate, and vibrate it with a flat vibrator for compaction until the surface is radiant with protoplasm. Before the final set of concrete, the calender shall be not less than 3 times. After calendering, there shall be no scratches on the surface, and pits and sand holes are strictly prohibited. After pouring, remove the concrete and mortar around the frame.
Maintenance:
At room temperature, after concrete cover plate is poured 12h, the surface is covered with film, and it is watered and maintained for not less than 7d.
Installation of cover plate: the direction of cover plate should be considered during transportation, and the cover plate is easy to break due to reverse force. Put the cover plate on the cable trench, and use theodolite at both ends of the cable trench to fix points every 20 meters. Pull the cable to adjust the straightness and flatness of the cover plate. 3mm thick rubber pad is placed at the bottom of the cover plate resting point to adjust the stability and surface flatness of the cover plate.
Quality acceptance:
According to Code for Quality Acceptance and Evaluation of Electric Power Construction Projects? 1 Part: Civil engineering (DL/T52 10. 1-2005) shall be inspected and evaluated according to the relevant provisions of 10.4. The main quality standards are:
◆ Steel frame with channel steel cover plate: length deviation of 3? mm； Width deviation 3? mm； Diagonal difference ≤3? Hmm.
◆ Channel cover plate: length deviation 5? mm； Width deviation 5? mm； Thickness deviation 3? mm； Diagonal deviation ≤5? mm； Surface flatness deviation ≤5? Hmm.
Well, this is the construction process of cable ditch cover plate. Is there a feeling of awakening after reading it? Anyway, rabbits feel this way. When we are in construction, we must pay attention to our own safety. Safety comes first, which is the most important thing. Then the construction must be carried out in strict accordance with the technical standards for cable trench construction. Before construction, we must make some preparations, such as technical preparation and material preparation. Finally, we must pay attention to environmental protection.