Other Information :
The following pages show capacities on the basis of vehicular load distribution and concentrated loading per meter of grating width for a given span. Calculation for concentrated load are similar in format to those for Light Duty Steel grating, except F = 138,000kN/m2. Calculations for vehicle loadings are based on AASHTO Standard Specifications for Highway Bridges and utilize the following formulas:
| M |
= |
Blending Moment, KNm |
| S |
= |
Section Modulus - m /m. of grating width |
| Ib |
= |
Moment of Inertia - m /bar |
| E |
= |
Modulus of Elasticity (2.0684x10⁸ kN/m²) |
| F |
= |
Allowable Bending Stress (138,000 kN/m²) |
| ℓ |
= |
Clear, Simple Span - m |
| D |
= |
Deflection - m |
| a |
= |
Partial Load Contact Parallel to Span - m |
| s |
= |
Centre-to-Centre Spacing between Bearing Bars - m |
| b |
= |
Partial Load Contact Dimension at 90° to Span - m |
| b |
= |
a + (2s) |
| P |
= |
Total Wheel or Partial Load Including Impact - kN |
| P₁ |
= |
P per Bearing Bar |
| P₁ |
= |
P x (s/b) |
|
Step 1. Determine M:
|
M= FSg
|
|
 |
Step 2. Substiting for M,
solve for ℓ:
|
(i) a > ℓ
|
(ii) a < ℓ
|
|
| Step 3. Check D*: |
| D= |
P1[ (2ℓ³) - (a²ℓ) + (a³/4)] |
| 96EIb |
|
|
| Maximum Traffic Conditions |
Wheel Load (kN.)
(1/2 of Axle Load
+30% Impact) |
Loading |
Load Distribution** |
| a |
b |
Truck Traffic
142.343 kN. Axle Load
Dual Wheels |
92.523 |
H-20 |
0.508m |
0.508+(2s) |
Truck Traffic
106.757 kN. Axle Load
Dual Wheels |
69.3922 |
H-15 |
0.3810m |
0.3810m+(2s) |
44.482 kN. Capacity Lift Truck
64.054 kN.
Vehicle
108.536 kN. Total Load (Rubber Tires)
85% Drive Axle Load |
59.962 |
5 Ton |
0.2794m |
0.2794m+(2s) |
26.689 kN. Capacity Lift Truck
43.593 kN. Vehicle
70.282 kN. Total Load (Rubber Tires)
85% Drive Axle Load |
38.833 |
3 Ton |
0.1778m |
0.1778m+(2s) |
8.896 kN. Capacity Lift Truck
18.683 kN. Vehicle
27.579 kN. Total Load (Rubber Tires)
85% Drive Axle Load (Rubber Tires) |
15.235 |
1 Ton |
0.0011m |
0.01016m,
0.1016+(2s) |
NOTES:
- For continuous spans, use continuity factor - 0.80
- **This distribution results in larger grating sizes for light trucks on shorter spans.
- Spans shown for H15/H20 reflect the more critical condition.
- The fork lift wheel loads and load distribution patterns depicted above, generally, and only partially, represent the broad range of rubber tired lift trucks available. For those applications falling outside of these examples, please contact the factory.
- Wheeled vehicles with urethane tires should NEVER be used in conjunction with open grid bar grating.
- HS20 is the same as H20 and HS15 is the same as H15. The “S” stands for semi-trailer.
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Information of a technical nature contained here is intended only for evaluation by technically skilled persons, with any use there to be at their independent discretion and risk. Such information is reliable when evaluated in the proper manner under the conditions as described.
Khansforge Industrial Grating shall have no responsibility or liability for results obtained or damages resulting from improper evaluation or use.
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