Prefabricated Beam-Slab House Stacking Project

In the prefabricated beam-slab house stacking project, it is crucial to pay close attention to the stacking layers, stacking principles, component details, and safety regulations. The specifics are as follows:

I. Stacking Layers for the Superposition Method of Prefabricated Roof Truss Beams

According to the 'Code for Construction of Concrete Structures' (GB 50666-2011) and engineering practice, when using the superposition method to produce prefabricated roof truss beams, it is generally recommended to stack a maximum of 3-4 layers. Beyond 4 layers, the load on the bottom components increases sharply, potentially leading to deformation and adhesion risks, and imposing extremely high requirements on the lifting process. The specific number of layers needs to be calculated and determined based on the following parameters:

• Component Self-Weight: For example, a prestressed concrete roof truss beam with an 18-meter span weighs 5-10 tons, requiring an assessment of the bottom layer's load-bearing capacity.
• Concrete Strength Grade: Typically not lower than C30; insufficient strength can easily cause cracking.
• Mold Rigidity: Steel molds are superior to wooden molds, reducing the risk of deformation.
• Foundation Bearing Capacity: Generally requires ≥150kPa; weak foundations need reinforcement.

II. Core Principles for Stacking Prefabricated Components

1. Zoning and Positioning: Divide exclusive stacking areas based on component type (beams, slabs, columns), specifications, and lifting sequence to avoid mixed stacking and set identification signs.
2. Foundation Treatment: The foundation of the stacking area needs to be compacted in layers (compaction degree ≥90%). For soft areas, lay a gravel cushion or pour a concrete cushion to ensure the total load does not exceed the foundation's bearing capacity.
3. Protective Measures: Place rubber pads or foam boards between components. Protect vulnerable parts (such as exposed rebar and embedded parts) in advance to avoid hard impacts.
4. Proximity to the Work Surface: The stacking area should be no more than 30 meters away from the lifting point. Stack components according to the principle of 'the first to be lifted is placed outside' to improve lifting efficiency.

III. Stacking Details for Different Components

• Prefabricated Shear Wall Panels: Preferably placed vertically, fixed with adjustable diagonal support brackets (angle ≥75 degrees), with a stacking height not exceeding 6 layers (when a single panel weighs ≤1.5 tons); for heavier components, reduce the number of layers (e.g., a maximum of 4 layers when weighing 2 tons per panel).
• Superimposed Slabs: When placed horizontally, align them and place rubber pads between each layer. The stacking height needs to be calculated based on the component's strength and the foundation's bearing capacity.
• Prefabricated Beams: Main frame beams (such as pre-tensioned prestressed beams) and secondary frame beams (such as ordinary concrete beams) need to be stacked separately to avoid deformation.

IV. Safety and Regulatory Requirements

• Lifting Safety: The higher the number of stacked layers, the larger the tonnage and longer the boom length of the lifting equipment required. The risk of high-altitude lifting increases, necessitating strict adherence to operating procedures.
• Laws and Regulations: Compliance with the 'Construction Law of the People's Republic of China', 'Regulations on the Administration of Construction Engineering Quality', and other relevant laws and regulations is required to ensure quality standards are met and adjacent relationships are properly handled.

Engineering Practice Reference: For medium-sized components (such as prestressed hollow slabs and roof truss beams), standard specifications strictly limit the stacking to 3-4 layers; for small components (such as prefabricated lintels and short columns), they can sometimes be stacked up to 5-6 layers, but calculations based on specific parameters are required.