Structural Calculations for Mobile Crane – Dubai Warehouses
Introduction
Mobile cranes are a vital part of industrial operations inside warehouses in Dubai—whether it’s for installing machinery, lifting HVAC units, or repositioning heavy goods. But using a mobile crane indoors isn’t as simple as driving it into place and lifting.
The floor slab and foundation must be structurally verified to ensure they can handle the concentrated wheel loads, outriggers, and dynamic forces from the crane operation.
In fact, Dubai Municipality (DM), Trakhees, and DDA all require structural checks before issuing permits for mobile crane use inside warehouses, especially if lifting involves loads exceeding 5 tons or if there’s a risk of overstressing existing slabs.
In this guide from Structural Solutions, we’ll walk you through:
- What structural calculations are required
- How crane loads affect warehouse slabs
- What codes and load combinations are used
- How to submit documents to Dubai authorities
- Real-life examples of structural verification for crane us
Table of Contents
Why Structural Calculations Are Required for Indoor Crane Use
Warehouses are designed for distributed loads—like racking systems or goods on pallets. A mobile crane imposes point loads, wheel pressures, and sometimes outrigger forces that exceed the original floor design.
Without proper verification, you risk:
- Cracked or collapsed floor slabs
- Damage to underground services (drainage, electrical, firefighting)
- Safety incidents or injury
- Authority penalties or stop work orders
When Are Structural Checks Required?
Structural calculations are typically mandatory when:
- Crane total capacity exceeds 5 tons
- Lifting involves a boom extension inside a building
- Crane is supported on a suspended slab
- Floor is raised or includes voids/services below
- The warehouse is older than 10 years
Even if the lift is brief, authorities may refuse operation without:
- Stamped structural drawings
- Slab load-bearing capacity report
- Outrigger and wheel point load analysis
Key Forces That Affect the Warehouse Slab
| Force Type | Description |
| Wheel Load | Heavy point loads transferred by the rubber wheels of the mobile crane |
| Outrigger Load | High-intensity loads at the base of stabilizers during lifting |
| Dynamic Load Factor | Load multiplier due to swinging or hoisting movement (typically 1.2–1.4× static load) |
| Concentrated Load | From counterweights or material being lifted |
| Axle Load | Combined loading from the mobile crane’s front and rear axles |
Engineering Checks Required
At Structural Solutions, we follow a systematic approach:
1. Slab Load Capacity Check
- Calculate the existing slab thickness, reinforcement, and concrete strength
- Compare against imposed wheel load pressure (kN/m²)
- Consider impact factor (DLF) for dynamic lifting
2. Subgrade and Soil Bearing Pressure
- If slab is ground-bearing, verify soil allowable bearing capacity
- Check whether crane load causes excess settlement or shear failure
3. Outrigger Pad Verification
- Ensure outrigger forces are dispersed over a wide area
- Pad size and material selection (e.g., steel plate or timber mat) are critical
4. Load Combinations (ASD / LRFD)
- We use combinations like:
- 1.2 DL + 1.6 LL + 0.5 Crane Impact
- 0.9 DL + 1.0 Crane Load + Wind (if applicable)
Applicable Codes & Standards in Dubai
| Standard / Code | Used For |
| ACI 318 | Concrete slab and reinforcement design |
| ASCE 7 | Load combinations and impact factors |
| BS 8110 / Eurocode 2 | Older warehouse structures |
| ASTM / AASHTO | Bearing pad checks, wheel pressure |
| DM Guidelines | Permit approval for heavy equipment |
Required Documents for Approval
To operate a crane inside a warehouse, authorities require a structural verification package:
| Document | Description |
| Warehouse Structural Drawings | Existing slab layout, reinforcement, and details |
| Crane Load Specs | Wheel load, axle spacing, boom length, weight chart |
| Load Calculation Report | Pressure comparison, factor of safety |
| Outrigger Load Assessment | Pressure, pad size, deflection check |
| Engineer’s Stamp | Certified structural engineer in UAE |
If the original drawings are missing, Structural Solutions can conduct a site inspection and generate as-built structural assumptions with cautionary recommendations.
Real-Life Project Example: Indoor Crane in JAFZA Warehouse
Project: Lifting 7-ton chiller unit inside JAFZA warehouse using 50-ton mobile crane
Issues:
- Warehouse slab = 150 mm thick with unknown reinforcement
- Crane outrigger load = 200 kN per point
- Authorities required slab check before allowing lift
Action:
- Structural Solutions performed a non-destructive slab scan
- Applied ACI 318 + ASCE load checks
- Designed steel plate pads (1.2 m x 1.2 m) for outrigger support
- Submitted stamped report to Trakhees
- Approval received in 5 working days
Site Safety Considerations
Beyond engineering, site safety is critical:
- Mark crane path and pad area with cones/barriers
- Keep staff and materials away during operation
- Coordinate with MEP team to avoid trench ducts or buried pipes
- Place fire extinguishers near lift zone
📌 Note: Trakhees and DM may conduct spot inspections during lifting.
How Structural Solutions Helps with Crane Calculations
We specialize in fast-turnaround crane structural checks, offering:
✅ Site inspection (if needed)
✅ Slab analysis and wheel load comparisons
✅ Outrigger pad design
✅ Drawing overlays (AutoCAD or PDF markups)
✅ Stamped structural report accepted by DM, DDA, Trakhees
✅ Submission guidance if authority approval is needed
Typical turnaround: 2–4 working days
FAQs
Q: Can I use a crane on a 150 mm slab?
✅ Maybe — depends on slab reinforcement, concrete grade, and load spread. We must analyze it first.
Q: Is Trakhees approval required for crane use in JAFZA?
✅ Yes. Trakhees (under EHS) regulates all construction in JAFZA and Palm Jebel Ali zones.
Q: Can you do the calculation even if we don’t have original slab drawings?
✅ Yes. We perform engineering assumptions with safety factors or offer scanning if required.
Q: What happens if we operate without slab verification?
❌ You risk structural failure, site damage, injury, and authority fines or shutdowns.
Conclusion
Operating a mobile crane inside a Dubai warehouse is a high-risk task that must be supported by structural verification and authority clearance. The concentrated loads from crane wheels and outriggers can easily exceed slab capacity if not properly checked.
At Structural Solutions, we help contractors, warehouse managers, and facility teams:
- Analyze crane loads
- Verify slab strength
- Design outrigger support pads
Prepare stamped structural reports accepted by Dubai authorities
📩 Need structural calculations for your next crane lift?
Get fast, reliable engineering support from Structural Solutions.
🌐 www.structuralsolutions.ae
📧 info@structuralsolutions.ae
📞 Call or WhatsApp now
We’ll help you lift with confidence—without compromising safety or compliance.
