Design / Loads & analysis

Distribution Factor

Live load distribution factors for a concrete deck on steel or precast concrete I-girders (AASHTO LRFD 4.6.2.2, cross sections a, e and k): interior and exterior girders, moment and shear, one lane and multiple lanes, with skew corrections.

Bridge

Girder typeSteel adds the rigid-body check

Span length, L

Number of girders, N_b

Girder spacing, S

Overhang to curb, d_eExterior web to inside face of barrier

Skew angle, θ

deg

Deck & girder stiffness

Deck thickness, t_sStructural, no wearing surface

Modular ratio, nE_girder / E_deck

—

Girder inertia, INon-composite

in⁴

Girder area, A

in²

Centroid offset, e_gGirder to deck centroid