Pre-engineered buildings

Rushank Mishra -2008BARC012 Gyandeep Jaiswal -2008BARC065 Akshay Gupta -2008BARC073

Pre-Engineered Building (PEB’s)

• A Pre-Engineered Building is a metal building that consists of light gauge

metal standing seam roof panels on steel purlins spanning between rigid

frames with light gauge metal wall cladding. It is a relatively flexible

structure vs. a conventional steel framed building. In other words, it has a

much greater vertical and horizontal deflection. The intent for this

publication is to recognize the nature and limitations of pre-engineered.

• Pre-engineered building concept is widely used in many of the

industrialized countries. It consists of a complete steel-framed building

system, with components pre-designed to fit together in a vast variety of

combinations to meet the unique requirements of specific end uses.

Different members in the assembly of the pre-engineered buildings

1. Eave strut 2. Roof panel 3. Roof purlin 4. Rigid frame rafter 5. Ridge line 6. End wall 7. Wall panel

8. Side wall 9. Rigid frame column 10. Downspout 11. Gutter 12. Ridge panel 13. Cable bracing or rod

bracing(at roof and wall)

Terminologies in Pre-Engineered Buildings

• Base Plate A plate attached to the base of a column which rests on the foundation or other support, usually secured by anchor bolts.

• Butt Plate The end plate of a structural member usually used to rest against a like plate of another member in forming a connection. Sometimes called a split plate or bolted end plate.

• Bay The space between frame centre lines or primary supporting members in the longitudinal direction of the building.

• Brace Rods Rods or cables used in roof and walls to transfer loads such as wind loads, and seismic and crane thrusts to the foundation. (Also often used to plumb buildings, but not designed to replace erection cables.)

• Clear Height: This is the distance between the Finished Floor Level to the bottom of knee joint. • Roof Slope (x/10): This is the angle of the roof with respect to the horizontal. The most common roof slopes are 0.5/10 and

1/10. Any practical roof slope is possible.

Typical Pre-Engineered Building Assembly

• The “Rigid Frame” assembly is the most common frame used in pre-engineered buildings.

• Basically, the rigid frame consists of a structural steel (hot-rolled) moment-resisting column and beam assembly that carries the cold-formed roof purlins (usually “Z” shaped) and wall girts (usually “C” shaped).

• In addition, diagonal rod bracing is required in the walls to resist horizontal loading on the building (i.e., wind loads and/or seismic). Rod bracing is also provided within the roof framing to resist "racking", or twisting of the building.

MEZZANINE FLOOR

DIFFERENT TYPES PRIMARY FRAMING SYSTEM

NORTH LIGHT

MONITOR TYPE

CANOPY

DETAILS of FITTINGS

PARTITION SIDEWALL ROOF EXTENSION MEZZANINE AT ENDWALL

ENDWALL ROOF EXTENSION WITH SOFFIT

CURVED EAVE WITH PROJECTION

CURVED EAVE WITHOUT PROJECTION

TYPES OF PURLIN

• Z-Section Purlin used in the roofing at sports complex, MANIT

Pre-Engineered Building Process

These are the stages which are involved in the Pre-Engineered building

ADVANTAGES

1. Fast Project Construction:

- Buildings are fabricated and delivered within a short period due to standardisation. - Fast erection because all members are field bolted.

2. Functional Versatility: - Modular construction.

- Large clear Spans (up to 100m). - Long Bay Spacing (up to 13m). - Buildings are easily expandable on all sides (allowing for future expansion).

3. Architectural Flexibility:

- Aesthetic features such as fascias, parapets and curved eaves greatly improve the appearance of the building. - Readily available interface details between steel and other materials (glazing, block wall, curtain wall, etc.).

4. Low Maintenance and Operating Costs:

- Virtually no maintenance required for all panels. - Roof requires only periodic cleaning. - Annual washing of Eave Gutters. - Watertight roofs.

Possible Disadvantages

1. Relatively short life-span 2. Sometimes has an “industrial” or

“warehouse” look to it 3. The foundation system is NOT designed by

the manufacturer 4. On-site alteration in design can’t be done.

Application of Pre-Engineered Buildings

• Commercial buildings • Auditoriums and Halls • Administration buildings

Factories

Warehouses

Stadiums Animal feed sheds

High rise buildings

Shipyards

Mall

Processing mills

Airport

Case Study: Sports Complex, MANIT, Bhopal

Flange Brace Angle

Ridge Line

Warehouse, Mandideep, Kirby Building Systems

C-Section Purlin

Z-Section Purlin

Diagonal bracing

I-Section Column

I-Section Column

Base Plate

Foundation

Bolting at base plate

Diagonal bracing for addition supports

Roof Panel

Warehouse, Samashgarh, Bhopal

Some of the significant advantages of PEB buildings over conventional buildings

PEB Buildings Conventional Building Aesthetically appealing appearance Special aesthetic design required

Reduced time because of international design standards & codes using standard sections and connections

Increased design time due to scratch and availability of less design aids

Higher resistance to seismic forces due to low weight flexible frames

Rigid heavy weight structures not suitable for seismic zones

30% less PEB steel structures weight through efficient use of steel

High weight due to excessive safety factor and the usage of heavier steel sections

Factory controlled quality Every project to be fabricated at site

Lower initial cost of peb steel buildings(cost per square meter about 30% less than the conventional) and faster delivery

Special design and features developed for each project at higher costs

Simple Foundation, easy to construct and light weight of PEB structures Extensive heavy foundation

Average delivery time 6-8 weeks Average delivery time 22-28 weeks