Civil Defense Door Frame Installation Pit Avoiding Manual: 6 fatal details that construction team members will not say

In the past five years of inspection of civil defense engineering, the unqualified rate of door frame installation is as high as 42%! As a technical responsible person who participated in 17 personal defense projects, I found that most of the projects have the problem of \”surprise correction before inspection\”. This article reveals the six key control points that are most easily overlooked in the construction site, and includes real rework cases. It is recommended that engineers collect and prepare them.

1. Positioning and discharging must be \”three aspects\” \”

1. Axis retrieval connection: The deviation between the center line of the door frame and the axle of the civil defense wall is ≤2mm (it is measured that the door fan cannot be closed due to a 3mm deviation)

2. Height control: The top height at the door is 15-20mm lower than the finished building surface (pre-reserved thickness of the decoration layer)

3. Verticality Testing: The vertical deviation of the door frame vertical bar should be ≤2mm/m (it is recommended to use laser pendant retrieval)

2. Embedded parts inspection and acceptance \”three checks and three tests\”

– Check specifications: straight stratum of the rum-shaped steel reinforcement ≥16mm, distance ≤250mm

– Check welding: door frame and embedded parts Welding length ≥80mm (welding height ≥6mm)

– Test firmness: use 1.5kg hand tap without hollowing

(Case: A project failed to detect air tightly in the protective door due to the welding of embedded parts)

3. Install the door frame \”Golden 3 hours\”

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1. Suspension stage: Use special spreaders, steel wire rope and door frame contact pad rubber protection

2. Fine window: Micro-tuning is completed within 30 minutes after installation (temperature changes can easily lead to deformation of the steel)

3. ​​Simultaneous fixation: adjustable oblique slugging is used, and direct welding of temporary support points is prohibited

IV. Fatal taboos in welding operations

1. Strictly prohibit arcing in the door frame (a project therefore Cracking is ordered to rework)

2. The solder should be welded on layers, and the layer temperature is controlled at 60-80℃

3. Magnetic particle detection and detection must be carried out within 24 hours after welding

5. \”Three Precautions\” for Concrete Stainless Steel

1. Anti-displacement: When the floor is cut, the height difference is ≤500mm

2. Anti-displacement: A cross-support bracket is installed in the door frame (it is recommended to use ∠50×5 corner steel)

3. Anti-leakage: Buried piping at the door frame and concrete joint, with a distance of 300mm

VI. 5 self-checks must be done before the experience

1. Gas densityTest: Use a feeler gauge to check the gap between the closed strips ≤1mm

2. Chain test: The opening force of the door fan is ≤150N (real test data)

3. Grounding resistance: Door frame grounding resistance value ≤0.2Ω

4. Paint film thickness: anti-staining paint ≥120μm, topcoat ≥60μm

5. Finished product protection: Detachable angle steel cover is installed at the bottom of the door frame

Xueyan Teaching: A residential area has a 5mm deviation in the verticality of the door frame, resulting in After the protection door is closed, the light leakage exceeds the standard. In the end, the 1.5m-wide walls on both sides are reconstructed, and 230,000 yuan is directly lost.

Civil defense engineering is nothing small, the quality of the door frame installation is directly related to the combat protection performance. Only by keeping a firm eye on \”mm-level precision control and zero tolerance for quality\” can we pass the most stringent human defense experience. Transfer this article to the project group to help the class team avoid walking!