Prefabricated House Lifting Balance Beam

The lifting balance beam for prefabricated houses needs to be custom-designed according to the specific characteristics of the components, with the core principle being to ensure even load distribution and prevent structural deformation.

I. Design Basics of Universal Balance Beams

The lifting of prefabricated houses can refer to the structure of universal lifting balance beams. Their main bodies are typically formed by welding steel plates or section steels, and they need to meet the following requirements:

• Structural Integrity: No cracks, weld failures, sharp corners, or other defects. The main load-bearing components (such as main beams and connecting plates) should have no significant deformation.
• Safety Factor: The design safety factor should be greater than 4 times to cope with dynamic loads and accidental impacts.
• Balance Mechanism: Achieve even load distribution through symmetrically distributed lifting lugs or cable lugs, avoiding single-point loading that could cause component tilting or damage.
  This type of design is suitable for scenarios with uniform load distribution, but the specifications of the main beam (such as the model of H-section steel and the thickness of steel plates) need to be adjusted according to the size and weight of the prefabricated house components.

II. Optimized Design Cases for Prefabricated Components

1. Lifting Plan for Portal-Frame Prefabricated Concrete Columns
   Adopt H-section steel (length ≥ 584mm) with end plates welded at both ends, connected to "Ω"-shaped clamps with bolts, achieving the following advantages:

   • Movable Connection: Adapts to columns with different cross-sectional sizes, avoiding direct contact between steel wires and the component surface, reducing wear risks.
   • Local Reinforcement: The combination of end plates and clamps can disperse lifting stresses, preventing local crushing of the concrete column.
     Note: This plan needs to be verified for its applicability to the overall lifting of prefabricated houses or only for individual components.

2. Anti-Deformation Design for Long Components
   Referring to pipeline lifting technology, a balance beam combining H-section steel and steel plates is used to solve the problem of deformation during the lifting of long components (such as prefabricated beams and slabs) through the following methods:

   • Multi-Point Support: Set multiple lifting points on the main beam to disperse the self-weight of the components.
   • Rigid Connection: Weld the steel plates and H-section steel into a whole to improve torsional rigidity.
   • Node Optimization: Use rounded transitions or reinforcing ribs at connections to avoid stress concentration.

III. Technology Transfer from Heavy-Load Scenarios

The 150t-class balance lifting beam used in wind power equipment manufacturing, with its characteristics of "heavy-load adaptation and precise coordination", can provide references for the lifting of large components of prefabricated houses:

• Dynamic Adjustment: Adapt to the center-of-gravity positions of different components through adjustable connectors (such as hydraulic jacks or bolt sets).
• Precision Assembly: Combine laser positioning or sensor monitoring to ensure the stable posture of components during the lifting process.
• Material Upgrade: Use high-strength steel (such as Q690) or alloy structural steel to reduce self-weight while improving load-bearing capacity.
  Note: Such technology needs to have its parameters adjusted according to the actual loads of prefabricated houses (such as single-story/multi-story, concrete/steel structures).

IV. Design Verification and Safety Specifications

After custom design is completed, the following steps need to be taken to ensure safety:

1. Strength Calculation: Verify the bending and shear strength of the main beam according to the Design Specifications for Cranes (GB/T 3811).
2. Stability Testing: Simulate lifting conditions to check whether the balance beam experiences side-tipping or local instability.
3. On-Site Test Lifting: Conduct test lifting with 50%-70% of the rated load, monitor the deformation amount, and adjust the connecting nodes.