Design of Long Span Steel Structures and Hangars [With Eave Bracing Concept]

Design of Long Span Steel Structures and Hangars

Amit Bharana, President, ERA BUILDSYS Ltd.

The majority of industrial buildings are made out of steel for obvious reasons of high strength/weight ratio. A study, on the Efficient Design of Large span hangars/structures, ensuring lighter foundations is presented.


Amit Bharana
Amit Bharana
Structure with Span larger than 40 m can be regarded as long span structures and need to be carefully designed keeping a balance of all the aspects like its weight, deflections (sway) and foundation forces. There are many combinations of designing large spans, like conventional truss & RCC column combination, truss & steel columns, Pre-engineered building (PEB) etc.

These days with the concept of PEB, the major advantage we get is the use of high strength steel plates (usually Fe 350), lighter but high strength cold form purlins, and 550 Mpa Galvalume profiled sheets. The use of PEB not only reduces the weight of the structure because high tensile steel grades are used but also ensures quality control of the structure. In the following study, we have designed a hangar using this modern concept of PEB.

Design Philosphy

The design under discussion is a 42 meter clear span hangar for aircrafts maintenance. We have designed this Hangar in 3D on STAAD software, for proper simulation of the load distribution uniformly in three co-ordinates system i.e. X, Y and Z. All the Basic loads i.e. Dead, Live, Wind, Temperature, seismic etc have been taken into consideration for designing of the frames. The structure has been designed under enclosed as well as open condition for application of wind loads, because of the opening & closing of the large sized Hangar Door.

The basic philosophy of rigid frame design is by adopting 'FIXED' or 'PINNED' column base conditions. A fixed column base is always a sturdy frame and helps in controlling allowable deflection (side sway) in the frames. Steel designers always prefer fixed base to pinned base frames. On the contrary, for foundation designers the design of foundations becomes a nightmare particularly in large span buildings. In fixed base design, the frame is rigid, but transfers heavy moments to the foundations. On weak soil, designing foundations becomes tedious task. Likewise for pinned support, the frame does not transfer any moment to the foundation and only vertical & horizontal reactions affect the design of foundation. It looks simple but in case of large spans, controlling deflections of frame in pinned base condition is a challenging task.

To control this deflection, the simplest way is to increase the Geometrical properties/sectional sizes of frame, but it is not advisable as it adds to the tonnage of the whole building, adding not only to the seismic forces but also adding to the cost subsequently. We need a solution wherein the sway of the frame can be controlled and the section sizes are also not increased.

The best way we could find is to 'BRACE' the frame to control the excess deflection. In the present case we have provided bracing at eave level (braced eave) on both sides of the structure along the length for this purpose. Span of this Eave bracing is taken approximately L / 10 of each side. We can observe in the following example that eave bracing is of a great help in controlling Horizontal deflections and leading to lighter foundation design.

NBM&CW January 2011

Click Here
To Know More / Contact The Manufacturer
Please fill in your details, we will contact you as soon as possible
Choose Title from the listPlease let us know your name.
Please let us know your Designation.
Invalid Input
Please let us know your email address.
Please let us know your City.
Please let us know your Contact Number.
Please brief your query.
Our other value-added services:

To receive updates through e-mail on Products, New Technologies & Equipment, please select the Product Category(s) you are interested in and click 'Submit'. This will help you save time plus you will get the best price quotations from many manufacturers, which you can then evaluate and negotiate.

Equipment & Machinery
Invalid Input
Building Products
Invalid Input

Everest Industries Executes PEB Project for Godrej Agrovet

Everest industries delivers a very complex 34.8m high G+6 multi-storey processing plant for Godrej Agrovet under difficult site conditions and with full safety compliance. Godrej Agrovet Ltd is among the largest oil palm producers Read More ...

Importance of Cold-Formed Steel in Seismic-Resistant Design of Structures

Cold Formed Steel is a product made by rolling steel or pressing steel in to semi-finished or finished goods at relatively low temperatures. Manufacturing of Cold Formed Steel (CFS) occurs at room temperature. Read More ...

Fire Resistance of Steel Structures

Structural steel frames are widely used in virtually all types of buildings and industrial installations. Fire-resistant design of structural steel framing is often required, depending on the fire risks Read More ...

Utilization of Steel Slag in Construction Materials

Paver blocks and steel slag binder bricks
Steel slag, a by-product of steel making, is produced during the separation of the molten steel from impurities in steel-making furnaces. Slag whether granulated or crystalline is an important Read More ...

Parametric Study for the Economical Depth of Long Span Arch Type Truss

Arch type space truss
A space frame or space structure is a truss-like, lightweight rigid structure constructed from interlocking struts in a geometric pattern. Space frames can be used to span large areas with few interior supports Read More ...

A Study on Properties of Polypropylene Fibre-Mesh

Fibre Mesh
Concrete is widely used constructional material with its high compressive strength. But it has some flaws like shrinkage and cracking, low tensile and flexural strength, poor toughness Read More ...

Pre-Engineered Construction in India a way forward!

Pre Engineered Construction
The Indian Construction Industry has witnessed a growth trajectory quite comparable to the development of the overall economic infrastructure of the country. The Indian Pre-Engineered Steel Buildings Read More ...

The Growing Demand of Aluminium Extrusions

Aluminium Extrusions
Aluminium - the third most abundant element in the earth's crust finds its implementation in many sectors due to its environment and user -friendly nature - in Building and Construction (B&C), power sector, automotive Read More ...

Steel in vogue for highrise buildings

high rise structure for office
There is no doubt looking at the way the population density particularly in metro cities, horizontal construction has been put on restriction, and comfortably spread out real estate is hard to find. Lack of space Read More ...

Interarch Infrastructure

Interarch office space
Heavy Steel Structure and large infrastructure projects hold nearly 20% share of the infrastructure work that is taking place in our country currently. Indian engineering industry has witnessed an extraordinary Read More ...

Pre-engineered Building PEB System hit Indian construction market

Pre-engineered Building
India has the second fastest growing economy in the world and a lot of it, is attributed to its construction industry which figures just next to agriculture in its economic contribution to the nation. In its steadfast Read More ...

Pre-engineered for Success: Tracking growth of PEB Steel buildings in India

PEB Steel buildings
As Infrastructure construction across the country is combining speed, economy, safety, strength and aesthetics at awe inspiring levels, steel structures, until now a primary foundation element, have risen Read More ...

Performance Assessment of Coated Steel

Coated Steel
There are different assessment options available for performance evaluation of coated steel. This article will give some inside to readers on important performance evaluation options related to physical testing Read More ...

Contemporary Industrial Building Methods

Contemporary Industrial Building
India is on its drive for a massive infrastructure upgrade and the construction techniques in the country have seen a major elevation over the past few years with the adoption of global practices Read More ...

Design Flexibility in Construction with Steel

Construction With Steel
Steel has become a universal building product due to its strength, versatility, durability and economic value. The use of coated steel for structures, roofing & wall cladding is growing rapidly because it offers Read More ...

TCS Campus Siruseri - Chennai

TCS Campus Siruseri
Tata Consultancy Services (TCS) India is building a new $200 million IT Park in Siruseri, Chennai. Designed by Uruguayan architectural firm Carlos Ott Architects in association with Carlos Ponce de León Architects, Read More ...

New Building Material & Construction World

New Building Material & Construction World
MGS Architecture

Modern Green Structures & Architecture

Modern Green Structures & Architecture

Lifting & Specialized Transport

Lifting & Specialized Transport

Indian Infrastructure & Tenders Week

Indian Infrastructure & Tenders Week