Gantry

CADOSS ^(R)	Project Useful Data			Job Ref WS2001.001
	Part of Structure Gantry Girder Formulae			Calc Sheet No. / Rev GGFormulae / 1
	Drawing Ref	Calc By M.G.D	Date Jan 2002	Check By	Date

Formulae for Maximum Bending Moments and Shears in Gantry Girders

The formulae given assume the following conditions:-

L = Span of Gantry Girder (adjacent girders are of equal span and are assumed to be simply supported).

C = Centres of end carriage wheels (two wheels are assumed for each end carriage, and where two cranes occur they are assumed to be identical in all respects).

G = The minimum centres between adjacent wheels of two end carriages (only applicable when two cranes are considered and when G < C ).

Mx = Maximum Bending Moment in the Gantry Girder, for the crane configuration shown.

Fv = Maximum Shear Force in the Gantry Girder, for the condition stated.

W = The loading from one wheel. (all wheels are assumed to have the same load).

Gantry Girder Formulae

Loading Configuration

Maximum Moment

Maximum Shear

C > 0.5858.L

x = L/2

Mx = W.L/4

x = 0

If C < L then

Fv = W/L(2.L - C)

If C > L then

Fv = W

C < 0.5858.L

x = L/2 - C/4

Mx = 2.W.x²/L

x = 0

Fv = W/L(2.L - C)

G < 0.5858.L

x = L/2 - G/4

Mx = 2.W.x²/L

x = 0

Fv = W/L(2.L - G)

x = L/2 + C/6 - G/6

Mx = 3.W. x²/L - W.C

x = 0

Fv = W/L(3.L - 2.G - C)

x = L/2 - G/4

Mx = 4.W. x²/L - W.C

x = C

Fv = W/L(4.L - 4.C - 2.G)

Notes

1. All possible crane configurations should be checked to determine the maximum force in the gantry girder.

Document (No. 20020120/WS/001)