Comprehensive Design Example for Prestressed Concrete (PSC) Girder Superstructure Bridge
3. Flow Charts
Live Load Distribution Factor Calculations Flow Chart Text
- Determine the type of cross-section, Table S4.6.2.2.1-1 (Design Step 5.1)
- Determine the Kg factor (S4.6.2.2.1) (Design Step 5.1.3)
- For skewed bridges, determine the skew correction factor for moment (if allowed by the owner) (S4.6.2.2.2e) and for shear (S4.6.2.2.3c) (Design Step 5.1.6)
- Determine LL distribution factors for moment for the interior girder under single lane and multi-lane loading (S4.6.2.2.2b) (Design Step 5.1.5)
- Determine LL distribution factor for shear for the interior girder under single lane and multi-lane loading (S4.6.2.2.3a) (Design Step 5.1.7)
- Apply the skew correction factor (Design Step 5.1.8)
- Determine the controlling (larger) distribution factors for moment and shear for the interior girder (Design Step 5.1.9)
- Divide the single lane distribution factors by the multiple presence factor for one lane loaded,1.2, to determine the fatigue distribution factors (Notice that fatigue is not an issue for conventional P/S girders. This step is provided here to have a complete general reference for distribution factor calculations.)
- Repeat the calculations for the exterior girder using S4.6.2.2.2d for moment and S4.6.2.2.3b for shear (Design Step 5.1.10)
- Additional check for the exterior girder for bridges with rigidly connected girders (Design Step 5.1.15)
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