1. Step wise procedure for Modeling, Analysis and Designof Monorails and EPs for
Monorails:
1. Please refer to mechanical data on monorails, based on the clear lift height
required / BOS specified by mechanical, note down the maximum depth possible
for the monorail beam, and elevation of the beam.
2. To start with, provide stools (supporting vertical tie members) at a c/c distance of
about 2 mts.
3. Modeling - geometry:
Monorail beams and stools supporting the monorail beams are modeled,
using beam elements.
Please provide appropriate offset to connect stool between top of beam
and bottom of slab (so that the stool length get reduced).
To start with assign some sectional details for the monorail beamd and
some section for the stool. Then revise it iteratively.
Some design data obtained here at our office is mailed to you, for an idea
to assign sections,
a) 15 t capacity - FB: 30m Elev – ISMB 250 beam with 22thk bot. plate.
Stool – ismb 100 with 6 thk plate at T & B
b) 15 t capacity - FB: 48.4m Elev – ISMB 300 beam with 22thk bot. plate.
Stool – ismb 100 with 8 thk plate at T & B
c) 5 t capacity - FB: 50m Elev – ISMB 250 beam with 8thk bot. plate.
Stool – ismb 100 with 6 thk plate at T & B
d) 2 t capacity - FB: 30m Elev – ISMB 250 beam. Stool – ismb 100
e) 3 t capacity - RWB: 53.5m Elev – ISMB 250 beam with 6thk bot. plate.
Stool – ismb 100
f) 25 t capacity - SGB: 60m Elev – ISMB 450 beam with 28thk bot. plate.
Stool – ismb 200 with 16 thk plate at T & B
(All beams have only bot plate)
4. Material – STEEL
5. Boundary – fixed at far end of stools (at Bot of slab) and at the ends of monorail
beam (only if the beam is connected on either side to walls through EPs).
2. 6. Loading – Static –
DL = (Self weight + Hoist load)
(Hoist load shall be taken from mechanical input. If input is not available, it shall
be assumed as 20 % of the capacity of the monorail).
LL – Lifted load (capacity of monorail) + impact factor of 10 % of the lifted load.
Hoist load and LL shall be applied as point loads at following points in
separate STAAD models / load cases:
a. Mid span of longest span between stools
b. Exactly below a stool (better below a middle stool rather than end
stool)
c. If a curved path is available for the monorail, have a separate load case
/ STAAD model where point loads are applied at the curved portion of
the beam.
d. If the monorail beam is fixed to walls, please find the nearest approach
point of the hoist to the wall (say 500mm from wall), and apply load at
the nearest point so as to get a maximum shear in the wall EP.
7. Loading – Dynamic
Mass lumping shall be done as follows:
Total mass lumped = Self weight (distributed mass) + Motor load (we have taken
it as half of hoist load, ie, 25 kN for 25t capacity crane) + Half of Lifted load (ie
capacity of monorail).
The masses shall be lumped at appropriate points where LL and hoist (static)
loads are applied, depending on the case analysed (Refer point 6) – any one point
lumped at a time.
8. Analysis – Static and Spectrum analysis are performed with appropriate slab’s
FRS.
9. Design is performed as per IS800 in STAAD (Please see ratios are not exceeding
0.9 so that sections will pass in AERB).
10. Bottom flange is designed as per the excel sheet attached (assuming one wheel
load on a flange acting at half the width of flange and BM distributed over a
length obtained by 30 degree dispersion). – Accordingly Bottom plate thickness
required is decided.
11. EP design is performed for the EP forces obtained
3. 12. Stiffeners are provided for the STOOL at the base (near slab end), and an
intermediate plate is provided between STOOL and base EP.
13. 6mm continuous fillet welds are provided for all connections.
