Professional Guide to Steel Road Plate Usage
This guide provides essential engineering specifications and safety requirements for the use of steel trench plates during construction. All data is based on HS-20-44 Traffic Loading standards. Road Plate Tabulated Data – Iron Lot
1. Introduction
Road plates (also known as trench plates or crossing plates) are essential for maintaining traffic flow over excavations during construction. These plates are designed to provide a stable, flush surface for vehicles and pedestrians while ensuring site safety. The following data is based on engineering specifications for Iron Lot, LLC steel plates (p. 1).
2. Choosing the Right Plate: Tabulated Data & Specifications
All plates listed below are made from minimum ASTM A36 steel, with a yield strength of 36 ksi, and are designed for HS-20-44 traffic loading (pp. 1, 4). Any span exceeding these table limits requires additional engineering (p. 4).
Plate Specifications
Plates must be minimum ASTM A36 Steel with a yield strength (Fy) of 36 ksi.
| Plate Thickness | Maximum Allowed Span | Common Sizes (ft) | Weight Range (lbs) |
|---|---|---|---|
| 1″ | 4′ – 6″ | 4×8, 4×10, 5×8, 5×10, 6×10, 8×10, 8×16, 8×20, 10×20 | 1,307 – 8,167 lbs |
| 1 1/4″ | 7′ – 0″ | 4×8 4×10, 5×8, 5×10, 6×10, 8×10, 8×16, 8×20, 10×20 | 1,633 – 10,208 lbs |
Note: 3/4″ thick plates are strictly for off-road use only (e.g., sidewalks or warehouses) and are not for on-road vehicle traffic (p. 4).
3. Installation Best Practices
Proper installation is critical to prevent movement and ensure safety (p. 4).
- Surface Contact: Plates must have positive contact with all supporting surfaces to prevent accidental movement from traffic deflection (p. 4). Cold patch can be used to fill voids beneath the plate (p. 4).
- Anchorage: Plates may require anchoring (pinning or welding) when speeds exceed 45 MPH or on slopes greater than 5% (p. 4).
- Trench Stability: This chart assumes a stable trench; stability must be determined by a competent person or engineer (p. 4).
4. Overlap & Transition Requirements
Ensure sufficient overlap to support the load and use transition ramps for smooth passage (p. 4).
- Minimum Overlap (Each Side):
- Asphalt (Speed < 45 MPH): 12 inches minimum per side (p. 4).
- Asphalt (Speed > 45 MPH): 24 inches minimum per side (p. 4).
- Dirt (Speed < 45 MPH): 24 inches minimum per side (p. 4).
- Transition Ramps: An 18″ minimum cold mix asphalt transition ramp should be installed all around the plate edges (p. 4).
5. Maintenance & Inspection
Regularly inspect plates to check for proper positioning, and ensure lifting points are clear for mechanical handling (p. 4).
Disclaimer: The information provided is based on specific engineering calculations and standards for construction use. It does not constitute professional engineering advice for specific site conditions.