|
Design Specification: |
|
ACI 318-83 & AASHTO |
Load Factor design method |
|
Capacity
reduction factors:
(ACI 318-83) |
|
Shear |
0.85 |
|
Axial compression combined with bending |
0.90 |
|
Material Properties: |
|
Welded wire fabric, min. specified yield stress |
65,000 PSI |
|
Steel reinforcement |
ASTM A-615-75, grade 60 |
|
Concrete, minimum specified compressive strength |
5,000 PSI |
|
Loading Data: |
| Load factor, dead load |
1.5 |
| Load factor, live load |
2.2 |
Truck axle load:
H2O
Interstate |
32,000 lbs
2 @ 24,000 lbs each |
| Impact (variable with depth) see AASHTO Bridge Specs,
1982 |
0 to 30% |
| Uniform internal pressure |
0.0 |
| Depth of water in box section |
equal to inside height |
| External ground water pressure |
0.0 |
| Soil Data: |
| Unit weight |
120 lb/ft3 |
| Ratio of lateral to vertical pressure from weight of
earth |
0.25 min to 0.50 |
| Additional lateral pressure from approaching truck
wheels |
700 + H, lbs/ft2 where H = earth cover, ft |
| External water table |
below box section invert |
| Effective weight coefficient |
1.0 |
| Structural Arrangement: |
| Min. concrete cover over steel |
1.0 in. |
| Haunch dimensions |
12" |
