SEMINAR ON “PRE ENGINEERED BUILDINGS”

Concept , Design & Construction

BY KUMBAR BHANU PRAKASH,M.Tech 1st Sem,Structural Engineering,DSCE, B’lore.

INTRODUCTION

Pre-determined inventory of raw materials that can satisfy a wide range of structural and aesthetic design requirements.

Pre-Engineered Buildings can be adapted to suit a wide variety of structural applications, the greatest economy will be realized when utilizing standard details. An efficiently designed Pre-Engineered Building can be lighter that the conventional steel buildings by up to 30%.

These are the structures basically produced at the factory with high tensile steel material by collecting complete information of the shed/building (viz; Length, Width, Height etc,).

The entire design of column, rafters and other accessories is based on International structural standards and involve high technical welding and quality production.

BUILDING COMPONENTS 1. Prime Steel Framing Systems

2. Secondary SystemsSecondary structural steel framing system refers to purlins, girts, eave struts, wind bracing, flange bracing, base angles,

clips and other miscellaneous structural parts.

3. Coated Steel Sheet Products

Colour coated sheets provide excellent resistance to corrosion and hence has become the most preferred material for a wide range of construction uses, particularly roofing and walling.

4. Decking SheetsFlordec Sheets (Corrugated Sheet for Composite Floor)

Flordec decking sheets are composite floor systems, constructed with cold-rolled corrugated steel decking covered with concrete.

Insulation (PEBI) Uniformly textured inorganic glass fibers bonded together

by a non-water soluble and fire-retardant thermosetting resin. It is free from coarse fibers and shot due to its mineral composition.

PEBI is non-toxic and not hazardous to health.

DESIGN OF PRE ENGINEERED BUILDINGS

The main framing of PEB systems is analyzed by the stiffness matrix method.

The frame data is assembled based on number of frame members, number of joints, number of degrees of freedom, the conditions of restraint and the elastic properties of the members.

The overall joint stiffness matrix is obtained based on the above frame data by summation of individual stiffness matrices considering all possible displacements.

The load vector is then generated based on the loading data and the unknown displacements are obtained by inverting the overall joint stiffness matrix and multiplying with the load vector.

Design Codes

AISC: American institute of steel construction manual

AISI: American iron and steel institute specifications

MBMA: Metal building manufacturer’s code

ANSI: American national standards institute specifications

ASCE: American society of civil engineers

UBC: Uniform building code

IS: Indian standards

Latest International Codes & Deflection

Design Criteria DESIGN METHOD: Allowable stress design method is

used as per the AISC specifications.

DEFLECTIONS: Unless otherwise specified, the deflections will go to MBMA, AISC criteria and standard industry practices.

PRIMARY FRAMING: Moment resisting frames with pinned or fixed bases.

SECONDARY FRAMING: Cold formed Z sections or C sections for purlins or girts designed as continuous beams spanning over rafters and columns with laps.

LONGITUDANAL STABILITY: Wind load on building end walls is transferred through roof purlins to braced bays and carried to the foundations through diagonal bracing.

DESIGN SOFTWARE

The latest software that is used for design is STAAD 2007.

ERECTION SYSTEMERECTION SYSTEM

Preparation for ErectionPreparation for Erection1.1. Pre Erection checksPre Erection checks2.2. Receiving Materials at siteReceiving Materials at site3.3. Unloading ContainersUnloading Containers

Erection of the FramingErection of the Framing1.1. Preparation of the First BayPreparation of the First Bay2.2. Main framesMain frames3.3. Mezzanine floorsMezzanine floors4.4. Crane BeamsCrane Beams

Sheeting & TrimmingSheeting & Trimming

Sheeting preparationSheeting preparation

Sheeting the wallsSheeting the walls

Sheeting the roofsSheeting the roofs

Miscellaneous trimmingsMiscellaneous trimmings

FasciaFascia

Self weight Self weight

30% lighter30% lighter Primary Member is Primary Member is

tapered sectiontapered section Secondary members Secondary members

are light weight rolled are light weight rolled framed “Z” and “C” framed “Z” and “C” sectionsection

Self weightSelf weight

More heavyMore heavy Primary members are Primary members are

Hot rolled “I” sectionHot rolled “I” section Secondary members are Secondary members are

“I” or “C” section “I” or “C” section which are heavy in which are heavy in weight.weight.

Delivery – average 6 to 8 Delivery – average 6 to 8 weeksweeks

Foundation-simple design, Foundation-simple design, easy to construct & light easy to construct & light wt.wt.

Erection cost and time- Erection cost and time- accurately knownaccurately known

Delivery- average 20 to Delivery- average 20 to 26 weeks26 weeks

Foundation- expensive, Foundation- expensive, heavy foundation heavy foundation required.required.

Erection cost and time- Erection cost and time- 20% more than PEB20% more than PEB

Overall price -30%lowerOverall price -30%lower Architecture-achieved at Architecture-achieved at

low costlow cost Erection process is easy, Erection process is easy,

fast, step by stepfast, step by step

Overall price - Higher Overall price - Higher price per square meter.price per square meter.

Architecture- achieved at Architecture- achieved at higher costhigher cost

Erection process is slow Erection process is slow and extensive field labor and extensive field labor is required.is required.

PRE ENGINEERED BUILDING vs CONCRETE BUILDINGS

APPLICATIONS

Industrial BuildingsIndustrial Buildings WarehousesWarehouses Commercial ComplexesCommercial Complexes ShowroomsShowrooms OfficesOffices SchoolsSchools Indoor StadiumsIndoor Stadiums Outdoor Stadiums with canopiesOutdoor Stadiums with canopies Gas StationsGas Stations Metro Stations, Bus Terminals, Parking LotsMetro Stations, Bus Terminals, Parking Lots Primary Health Centers, Angan wadi’sPrimary Health Centers, Angan wadi’s And many more…And many more…

Industrial Industrial BuildingBuilding

Parking lotsParking lots

Indoor StadiumsIndoor Stadiums

Railway StationRailway Station

Aircraft HangarsAircraft Hangars Metro StationMetro Station

Wear houseWear house High rise BuildingHigh rise Building

ADVANTAGES

Aesthetic AppealAesthetic Appeal Faster CompletionFaster Completion EconomicalEconomical Seismic ResistanceSeismic Resistance Ease of ExpansionEase of Expansion Maintenance FreeMaintenance Free Large Clear SpansLarge Clear Spans Controlled QualityControlled Quality

CONCLUSION

PEB concept has been very successful and well established in North America, Australia and is presently expanding in U.K and European countries. PEB construction is 30 to 40% faster than masonary construction. PEB buildings provide good insulation effect and would be highly suitable for a tropical country like India.

The pre-engineered building calls for very fast construction of buildings and with good aesthetic looks and quality construction. Pre-engineered Buildings can be used extensively for construction of industrial and residential buildings.

REFERENCES

KIRBY Building System KUWAIT. KARTHIK FABRICATORS India P Ltd. MULTCOLOR PROJECTS India Ltd. LLOYD INSULATIONS India Ltd MABANI STEEL LLC, U.A.E STRUCTURAL ENGINEERING at WSP Asia Limited

Philippines ZAMIL STEEL Building India Pvt.Ltd