NATIONAL ALUMINIUM COMPANY LIMITED - Rites

18.3 ADDITIONAL DESIGN CRITERIA
a) Design of steel structures shall be done in accordance with IS:800 IS:800-1984. 1984.
b) In absence of specified dynamic factor to be considered for the load from the belt
conveyor, a dynamic factor of not less than 1.3 shall be considered for the design of
floor beams and gallery girders.
c) Gallery trusses and stringers as well as floor be beams ams of junction house shall be checked
for obviating occurrence of resonance and shall be designed such that the ratio of
applied frequency to natural frequency shall not lie within the range 0.7 to 1.5.
d) As far as possible gallery structure shall be mmade
ade independent of junction houses. A
trestle shall be planned close to the junction house to avoid gallery span resting on the
junction house.
e) The contractor after the award of work shall submit design criteria to owner /
consultant for approval befo before submission of design drawings.
f) The design drawings shall be submitted in complete for a unit along with design
calculations both in hard copy and soft copy. Design shall be done using STAAD.
g) The effective ratio of utility of all main sections shall be limited to 0.85
h) Structural schematic general arrangement with plans at various levels, elevations along
each row and axes, sections, considered loads and load diagrams with location etc. and
Structural design drawings with BOQ and Table of me members mbers containing design forces shall
be submitted for Owner’s/Consultant’s approval. However the approval shall be limited
to checking of overall dimensions, general stability of system, effective load transfer and
deflection limits etc. The approval shall not relieve the contractor of his responsibility of
correctness in design, adequacy of connections, accuracy etc.
i) Submission of Stability certificate for all the steel structures is under the scope of the
contractor.
18.4 Description of loads and loading codes
a) Unless specified otherwise hereinafter, all the live loads shall be considered in
accordance with IS: 875 (Part (Part-2) -1987.
b) Wind loads shall be considered in accordance with IS: 875 (Part (Part-3)-1987. 1987.
c) Seismic loads shall be considered in accorda accordance nce with IS:1893(part1)
IS:1893(part1)-2002 and
1893(part 4)-2005
d) Live loads from conveyor on the gallery floor shall be as per conveyor suppliers load
data.
e) While designing the fixed support/rigid trestles in an expansion block of conveyor
gallery the following loads (in addition to wind load) shall be considered.
Technical Specification:Sec-4,System System Parameters, Operation & Control Philosophy
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