I. Basic Classification and Characteristics of Cranes

1. Type Classification

• Main Types:
  • Single-girder crane (≤10t)
  • Bridge crane (double-girder)
  • Electric hoist (single-line motion)
  • Wall-mounted crane (special applications)

2. Operation Methods

• Ground Control Type:
  • Relatively flexible structural requirements
  • Lower deflection control standards
• Cabin Control Type:
  • Strict deformation control indicators
  • Requires steel ladders, walkways, and other auxiliary facilities

II. Key Technical Parameters

1. Basic Parameters

• Lifting Capacity:
  • Unit: t
  • Notation method: main/auxiliary hook (e.g., 75/20t)
• Span Design:
  • Unit: mm
  • Standard span series:
    • 10500 (corresponding to building 12000)
    • 13500 (corresponding to building 15000)
    • 16500 (corresponding to building 18000)
    • 19500 (corresponding to building 21000)
    • 22500 (corresponding to building 24000)
    • 25500 (corresponding to building 27000)
    • 28500 (corresponding to building 30000)
    • 31500 (corresponding to building 33000)

2. Working Class

Based on GB/T 3811 standard:

• Utilization class (U0~U9)
• Load state (Q) Combined to determine working class (A1~A8)

III. Structural Design Points

1. Load Calculation

• Vertical Load Amplification Factor:
  • Considers self-weight and accessories
  • Multiplied by amplification factor
• Horizontal Loads:
  • Transverse: trolley braking force
  • Longitudinal: crane braking force
  • Calculation basis: wheel pressure percentage

2. Support Design

• Type Selection:
  • Plate support: simple fabrication, large eccentricity
  • Flange support: small eccentricity, complex fabrication
• Layout Principle:
  • Middle support: preferably flanged
  • End span: plate type

3. Rail Connection

• Bolt Connection:
  • Minimum beam width: 280mm
  • Consider upper flange reduction
• Welded Connection:
  • Good structural integrity
  • Simpler strength calculation

IV. Calculation and Verification Points

1. Load Combinations

• Fatigue and Deformation Calculation:
  • Use standard combination
  • No dynamic factor
• Bearing Capacity Calculation:
  • Consider dynamic factor
  • Flexible hook crane: 1.05 (A1~A5)
  • Rigid hook crane: 1.1 (including A6~A8)

2. Multiple Crane Design Considerations

• Strength verification: Maximum 2 cranes
• Deformation verification:
  • Vertical: ≤2 cranes
  • Horizontal: 1 crane (maximum load)
• Fatigue verification: 1 crane (maximum load)

V. Atlas Application Guidelines

1. 20G520-1 Atlas Usage Notes

• Based on dual crane conditions
• Default welded rail connection
• Large span gradation
• Horizontal load impact not considered

2. Tie Rod Design Recommendations

• Independent tie rod recommended
• Consider constraint effect
• Add knee braces when necessary

VI. Design Optimization Suggestions

• Specific calculation based on project parameters
• Reference atlas construction practices
• Focus on node detail design
• Consider installation convenience
• Emphasize maintenance requirements