Structure Designing
Pre-Engineered Steel Buildings
Types of Pre-Engineered Buildings
- Muti-Gable
- Mono slope clear span
- Lean-to
- Flat Roof
- Roof System
- Mezzanine Floor
- Clear Span with Top running Crane
PEB Design Parameters
- Building Length, Width, Height
- The clear span between bearing points
- Bay spacings; Roof Slopes
- Live Loads on roof & frames
- Dead Loads
- Wind Loads
- Earthquake (Seismic) Zone
- Deflection Criteria
Design Methodology:
- To identify and design the structure as per the various loads and load combinations acting on the structure.
- To design the industrial warehouse as per IS codes.
- To determine the least possible weight of the structure so that the cost will reduce.
- To check the structure as per IS code in the staadprov8i software is safe or not.
- To arrange the section at the identified location only as per the requirement of that spot.
- As per bending moment diagram, the sections will vary along the length.
- As there is smallest section, steel is saved as well as cost is reduced significantly.
CODES AND STANDARD
- IS Code Practice for General Construction in Steel : (IS:800-2007)
- IS Code Practice for Hot rolled sections and plates : (IS:2062)
- IS Code of Practice for Cold Form : (IS:801-1975)
- IS Code of Practice for Design Loads Part-3-: : (IS:875-1987)
- IS Code of Practice for Earth Quake Loads Part-1: (IS:1893-2002)
- American Welding Society Specification : (AWS D1.1.98)
- American Institute of steel construction: (AISC)
- Metal building manufactures association :(MBMA)
- Eurocode 3: Design of steel structures (EN 1993)
MATERIAL OF CONSTRUCTION
- Built up Section from high tensile steel grade as per ASTM A572 Grade-50, 345MPa.
- Hot rolled secondary members for channels, angles, pipes confirming ASTM A572, Grade36, 250MP / IS: 2062, Gr. A, 250Mpa.
- Cold formed secondary member conforming to ASTM A570M grade 50, 340Mpa / IS513, IS801.
- Anchor bolts for foundation-ASTM A 36M / IS 2062.
- Bracing and sag rods to conform to IS 2062, Gr. A, 250Mpa / ASTM A36,
- 250Mpa. Minimum dia. for sag rods shall be 16 mm.
- Primary connection bolts- High strength bolts, ASTM A325-ANSI
- Secondary connection bolts – Machine bolts ASTM, A307 / IS: 1367 CLASS4.6 (part 1 to 3).
- Self drilling self tapping screws – AS3566.1-2202 corrosion resistance class3 or equivalent.
- Wind ties, if required, shall be minimum flat of size 40 mm x 6 mm.
- Structural steel where ever not mentioned shall conform to Grade A of IS: 2062
TECHNICAL SPECIFICATIONS FOR PRE ENGINEERED BUILDINGS (PEB)
- Angle/Rod bracing for roof and wall is considered.
- Main frame column base considered as pinned support.
- Built up & Hot rolled sections to be designed as per Manual of Steel Construction, 9th edition, American Institute of Steel Construction (AISC) & IS: 800.
- Cold formed members to be designed as per 1996 Edition of Cold-Formed Steel Design Manual, American Iron and Steel, Institute (AISI), IS: 801&
- IS: 513.Welding shall be applied in accordance with: American Welding Society
- (AWS D1.1.98) Structural Welding Code - Steel. IS: 800, IS: 813 & IS: 816.
PERMISSIBLE DEFLECTIONS
The permissible vertical deflection for structural steel members shall be as specified below:
- For Primary Span / 180
- For Secondary Span / 150
- Steel Structure simple span Beam shall be Span / 240.
- Steel Structure for cantilever span Beam shall be Span / 120.
- Permissible horizontal displacement at crane level / eaves level shall be Height / 150.
- Permissible Deflection for Purlin shall be Span / 150. Permissible Deflection for Side Runner Shall be Span / 150
- Permissible Deflection for Chequered Plate/Grating shall be Span / 200 or 6 mm, whichever is lower