Bridge Load Calculator

STRUCTURAL

Bridge Load Calculator

AASHTO LRFD · HL-93 · Dead & Live Loads · Reactions · Shear · Moment

kN kN·m AASHTO

Bridge dimensions

Span length (L)

Bridge width (W)

Number of girders

—

Girder spacing (S)

Girder depth (d)

Support type

—

                            Span-to-depth ratio
                            —
                            —
                        

Deck area — m²

Girder spacing — m

Bridge classification — —

L/d ratio = span / girder depth

Bridge elevation

30.0 m d

Elevation view — simply supported girder bridge

Geometry checks

L/d ratio ✓ OK

Girder spacing ✓ OK

Slenderness ✓ OK

Support type Simply

Dead loads (DC)

Deck slab (self-weight)

kN/m

Girder self-weight

kN/m

Barriers / parapets

kN/m

Wearing surface (DW)

kN/m

                            Total dead load (DC)
                            —
                            kN/m
                        

Dead load per girder — kN/m

Total DC + DW — kN/m

w_DC = Σ dead loads

Live loads (HL-93)

Design truck (HL-93)

Lane load (uniform)

kN/m

Impact factor (IM)

—

                            Truck load (with IM)
                            —
                            kN
                        

Lane load — kN/m

HL-93 equivalent — kN

Multiple presence factor 1.20 —

HL-93 = truck + lane + impact

Load comparison

Load comparison (kN) — dead vs live vs total

HL-93 loading

HL-93 design truck + lane load (AASHTO LRFD)

Analysis results

Total factored load (w_u)

kN/m

From load combination tab

Concentrated load (if any)

Load position (x)

                            Reaction at A (RA)
                            —
                            kN
                        

                            Reaction at B (RB)
                            —
                            kN
                        

Max shear (V_max) — kN

Max moment (M_max) — kN·m

Deflection (Δ) — mm

R_A = w·L/2 + P·b/L | M_max = w·L²/8 + P·a·b/L

Bending moment diagram

_max —

BMD for simply supported beam

Shear force diagram

_max —

SFD — constant for UDL, step for point load

Load factors (AASHTO LRFD)

Dead load factor (γ_DC)

—

Wearing surface factor (γ_DW)

—

Live load factor (γ_LL)

—

Combination type

—

Dead load (DC) — kN/m

kN/m

Wearing surface (DW) — kN/m

kN/m

Live load (LL) — kN/m

kN/m

                            Factored load (wu)
                            —
                            kN/m
                        

DC contribution — kN/m

DW contribution — kN/m

LL contribution — kN/m

Combination Strength I —

w_u = γ_DC·DC + γ_DW·DW + γ_LL·LL

Load contribution

Factored load contribution by source

Combination summary

Load factor type Strength I

Dead load factor 1.25

Live load factor 1.75

Resulting w_u —