Project 2

PEB is cost saving structure

It is 30% cost saving than conventional steel

PEB is time saving structure

it is 30%-50% saving in time.

it have fast delivery

it can quickly erected

PEB have superior quality

PEB is energy efficient building, walls and roofs are insulated properly.

PEB is larger than span.

PEB requires less maintanance

PEB is flexible for future expansions.

Components of pre engineering building

primary structural element

Main frame

Gable frame

Secondery structural element

purlins and girts

eave strut

bracing

roof and wall cladding

Canopy

canopy is an overhead roof structure, that has open sides, canopies are typically intended to provide shelter from rain and sun, but may also be used for decorative purpose, or to give emphasis to a route or part of a building.in classical architecture, canopy was a projecting hood or cover that was suspended over an alter, statue or niche, and was commonly found in churches throughout the middle ages.

• Canopy in construction evolved as an architectural feature during the Renaissance. During that period, it was employed as a fixed structure supported on pillars. Canopies can be supported by the building attached to ground mountings cables, upright support posts, and stanchions. Today, canopies are also constructed as independent structures.

• Mezzanine floor - A mezzanine floor is an intermediate floor between main floors of a building, and therefore typically not counted among the overall floors of a building. Often, a mezzanine is low-ceilinged and projects in the form of a balcony. The term is also used for the lowest balcony in a theatre, or for the first few rows of seats in that balcony. 
• Applications - In industrial applications, mezzanine floor systems are semi-permanent floor systems typically installed within buildings, built between two permanent original stories. These structures are usually free standing and in most cases can be dismantled and relocated. Commercially sold mezzanine structures are generally constructed of three main materials; steel, aluminium, and fibreglass. The decking or flooring of a mezzanine will vary by application but is generally composed of b-deck underlayment and wood product finished floor or a heavy duty steel, aluminium or fibreglass grating.
• The mezzanine is often used in shops and similar spaces for storage of tools or materials. The high roof of the shop is ideal for a mezzanine, and offices can be put either below or above it. Mezzanines are frequently used in industrial operations such as warehousing, distribution or manufacturing. These facilities have high ceilings, allowing unused space to be utilized within the vertical cube. Industrial mezzanine structures are typically either structural, roll formed, rack-supported, or shelf supported, allowing high density storage within the mezzanine structure.
• Bracings - A braced frame is a really strong structural system commonly used in structures subject to lateral loads such as wind and seismic pressure. The members in a braced frame are generally made of structural steel, which can work effectively both in tension and compression.
• Advantages of bracings - 
• Under bending loads compression flange of the main beam tend to buckle horizontally. The Bracing systems resist the buckling of the main beam.
• Bracing system help in distributing the vertical and lateral loads between the main beams.
• Sag rod - a rod for preventing the sagging of an open-web steel joist that is used as a purlin with its depth at right angles to a roof slope.
• All sag rods shall be min. 16mm dia rod confirming to IS; 2062 Grade A, made from first quality steel of standard manufacturer like TISCO / SAIL / IISCO / VSPL / ESSAR / JINDAL.  If sag angles are used, they must be GI, Min 1.6 mm thk and must have slenderness ratio less than 350 in case of IS Codes and 300 in case of AISC 360 - 2010.
• Loads on pre engineered buildings (PEB) - 
• Dead load - self weight, connections and other accessories. Weight of roof sheets, purlins, sag rod, fly braces, bracings.
• Mezzanine floor, deck slab. crane self weight, gantry girder self weight.
• Live load - Gravity load produced by occupancy of structure. Roof live load 75 kg/m^2. Water in eave gutter. Mezzanine floor live load as per occupancy.
• Collateral load - sprinkler system, drop ceilings, HVAC equipment, lighting fixtures.
• Wind load -  Wind pressure, as per site loaction. External wind coefficiants as per dimensions of building. Internal wind coefficiants as per openings.
• Seismic/Earthquick load - response structure to design spectrum as in IS 1893. Masses considered in structure to generate seismic load due to dead load + live load (25 or 50%) depending or intensity (No LL on roof).
• Zone factor, importance factor, reduction factor, damping ratio as in IS 1893.
• Crane load - Impact factor for vertical 1.25 of static load. For transverse 10 % of crab and lifting weight. Longitudinal 5% of static wheel load.  
• Load combinations of pre engineered building as per IS 800 : 2007.
• Strength design - 
• 1.5DL + 1.5LL.
• 1.2DL + 1.2LL + 1.2WL/EL.
• 1.5DL + 1.5WL/EL.
• 0.9DL + 1.5WL/EL.
• Servicebility design - 
• 1.0DL + 1.0LL.
• 1.0DL + 1.0WL/EL.
• 1.0DL + 0.8LL + 0.8WL/EL.
• Strength design with crane - 
• 1.5DL + 1.5LL + 1.05CL.
• 1.5DL + 1.05LL + 1.5CL.
• 1.2DL + 1.2LL + 0.53CL + 1.2WL/EL.
• 1.5DL + 1.5 WL/EL.
• 0.9DL + 1.5WL/EL.
• Servicebility design with crane - 
• 1.0DL + 1.0LL + 1.0CL.
• 1.0DL + 1.0WL/EL.
• 1.0DL + 0.8LL + 0.8LL + 0.8WL/EL.
• Analysis of pre engineered building - 
• Static method based on stiffness matrix method is carried out in staad pro.
• Rafter column frames modeled and analysed as moment frame system in transverse direction to resist both gravity and lateral loads.
• Longitudinal bracing system along with wall and roof functions as lateral load resisting system in longitudinal direction.
• Bracings are analysed and designed using staad and validated spread sheets.
• Secondary members (purlins/girts) are analysed manually as continuous beams using validated spread sheets.
• After analysis is done we can access various results in post processing mode and output file is generated.
• Various results available are displacements, reactions, base pressure, instabilities, member forces and moments, stresses, unity check, animations, contour diagrams etc. 
• Limit states - 
• The structural analysis results are studied under two limit states.
• Limit state is state beyond which the structure no longer fulfills the specified performance requirements.
• Classification - 
• Limit state of strength.
• Limit state of servicebility.
• Limit state of strength - 
• Limit state of strength includes member forces and moments, reactions, unity check etc.
• The section is safe in limit state of strength when utilization ratio < 1.0.
• Utilization ratio of typical frame is shown below. It is frame in given ratio.
• Limit state of servicebility -
• Deflection limits shall be considered as per table 6 of IS 800:2007.
• Maximum deflection limits if purlins checked under various combinations of dead and live load is to be restricted to span/240.
• For combination of dead, imposed and wind loads, purlins, deflection is to be limited to span/150.
• Maximum deflection limit for rafter checked under various combinations of dead loads and imposed loads is to be restricted to span/180.
• Maximum permissible deflections at tip of cantilever shall be limited to span/120.
• For columns nott supporting crane girders, under worst load case combination of DL, LL, WL/EL and temperature load the deflection limit shall be considered as L/150.